Equipoise arm assembly

Claim 2

An equipoise arm assembly for supporting an article in equipoise, the equipoise arm assembly comprising: a support arm with a body portion with a proximal end and a distal end; a proximal arm joint pivotally coupled to the proximal end of the support arm at a proximal pivot axis; a means for supporting an article relative to the distal end of the support arm; a spring arrangement with a distal end coupled to the body portion of the support arm and a proximal end pivotable about an effective pivot axis spaced a given distance from the proximal pivot axis to create a spring force moment arm of a given length whereby the spring arrangement will tend to provide a resistive torque in support of the support arm against rotation in a given direction wherein the spring arrangement includes a spring member with a proximal end and a distal end; and a means for altering the distance between the effective pivot axis of the spring arrangement and the proximal pivot axis of the support arm during a pivoting of the support arm to change the length of the spring force moment arm thereby to change the resistive torque per unit spring force provided by the spring arrangement in support of the support arm wherein the means for altering the distance between the effective pivot axis and the proximal pivot axis comprises a stop surface disposed adjacent to a portion of the spring arrangement in combination with an open area adjacent to the stop surface wherein the support arm can be pivoted through a given range of pivoting wherein the portion of the spring arrangement will pivot through at least part of the open area until the portion of the spring arrangement contacts the stop surface thereby to prevent further pivoting of at least part of the portion of the string arrangement whereby the effective pivot axis of the spring arrangement and the spring force moment arm will be altered.

Claim 3

The equipoise arm assembly of claim 1 wherein the means for altering the distance between the effective pivot axis and the proximal pivot axis to change the length of the spring force moment arm creates a non-linear resistive torque pattern that corresponds more than a linear resistive torque pattern would to the non-linear torque pattern imparted on the proximal arm joint by the weights of the support arm and the article over a range of pivoting of the support arm.

Claim 4

The equipoise arm assembly of claim 1 wherein the spring arrangement includes a pivot link coupled to the proximal arm joint wherein the stop surface and the open area are disposed adjacent to the pivot link whereby the pivot link can be pivoted through a given range of pivoting until at least a portion of the pivot link makes contact with at least a portion of the stop surface whereby that at least a portion of the pivot link will be prevented from further pivoting whereby the effective pivot axis of the spring arrangement and the spring force moment arm will be altered.

Claim 5

The equipoise arm assembly of claim 3 wherein the pivot link comprises a flexible member.

Claim 6

The equipoise arm assembly of claim 4 wherein the stop surface is variably sloped whereby the pivot link will progressively make increasing contact with the stop surface as the support arm is pivoted thereby creating a moving effective pivot axis for the spring arrangement.

Claim 7

The equipoise arm assembly of claim 3 wherein the spring arrangement includes multiple pivot links.

Claim 8

The equipoise arm assembly of claim 6 wherein the stop surface is variably sloped whereby the pivot links will make sequential contact with the stop surface as the support arm is pivoted thereby creating a moving effective pivot axis for the spring arrangement.

Claim 9

The equipoise arm assembly of claim 7 wherein the pivot links are rigid and wherein the stop surface has a plurality of variably sloped subsections for contacting a plurality of the pivot links.

Claim 10

The equipoise arm assembly of claim 3 wherein the open area comprises a pivot alcove in the proximal arm joint.

Claim 11

The equipoise arm assembly of claim 1 wherein the means for altering the distance between the effective pivot axis and the proximal pivot axis operates to increase the distance between the effective pivot axis and the proximal pivot axis during a pivoting of the support arm to increase the length of the spring force moment arm thereby to increase the resistive torque per unit spring force provided by the spring arrangement in support of the support arm.

Claim 12

The equipoise arm assembly of claim 1 wherein the means for retaining an article relative to the distal end of the support arm comprises a distal arm joint pivotally coupled to the distal end of the support arm at a distal pivot axis.

Claim 13

The equipoise arm assembly of claim 11 wherein a parallelogram pivoting arrangement is established between the support arm and the proximal and distal arm joints whereby the distal arm joint will demonstrate parallel movement relative to the proximal arm joint.

Claim 14

The equipoise arm assembly of claim 12 wherein the parallelogram pivoting arrangement is provided by first and second control arms and the proximal and distal arm joints wherein each control arm has a proximal end pivotally coupled to the proximal arm joint and a distal end pivotally coupled to the distal arm joint.

Claim 15

The equipoise arm assembly of claim 13 further comprising an arm housing with an open inner volume for housing at least a portion of the spring arrangement and at least a portion of the first control arm.

Claim 16

The equipoise arm assembly of claim 14 wherein the arm casing has at least one window therein for enabling an exposure and accessing of a portion of the spring arrangement.

Claim 17

The equipoise arm assembly of claim 12 wherein the parallelogram pivoting arrangement includes at least a first control arm and wherein the distal end of the spring arrangement is coupled to the first control arm.

Claim 18

The equipoise arm assembly of claim 11 wherein the support arm comprises a first support arm and further comprising a second support arm with a body portion, a proximal end pivotally coupled to the distal arm joint to pivot about a proximal pivot axis, and a distal end pivotally coupled to a second distal arm joint and further comprising a means for supporting an article relative to the second distal arm joint whereby the second support arm, the second distal arm joint, and the means for supporting an article relative to the second distal arm joint comprise the means for supporting the article relative to the distal end of the first support arm.

Claim 19

The equipoise arm assembly of claim 17 further comprising a spring arrangement with a distal end coupled to the body portion of the second support arm and a proximal end pivotable about an effective pivot axis spaced a given distance from the proximal pivot axis of the second support arm to create a spring force moment arm of a given length whereby the spring arrangement will tend to provide a resistive torque in support of the second support arm against rotation in a given direction wherein the spring arrangement includes a spring member with a proximal end and a distal end and further comprising a means for altering the distance between the effective pivot axis of the spring arrangement and the proximal pivot axis of the second support arm during a pivoting of the second support arm to change the length of the spring force moment arm thereby to change the resistive torque per unit spring force provided by the spring arrangement in support of the second support arm.

Claim 20

An equipoise arm assembly for supporting an article in equipoise, the equipoise arm assembly comprising: a first support arm with a body portion with a proximal end and a distal end; a proximal arm joint pivotally coupled to the proximal end of the first support arm at a proximal pivot axis; a means for supporting an article relative to the distal end of the first support arm comprising a distal arm joint pivotally coupled to the distal end of the support arm at a distal pivot axis; a spring arrangement with a distal end coupled to the body portion of the first support arm and a proximal end pivotable about an effective pivot axis spaced a given distance from the proximal pivot axis to create a spring force moment arm of a given length whereby the spring arrangement will tend to provide a resistive torque in support of the first support arm against rotation in a given direction wherein the spring arrangement includes a spring member with a proximal end and a distal end; a means for altering the distance between the effective pivot axis of the spring arrangement and the proximal pivot axis of the first support arm during a pivoting of the first support arm to change the length of the spring force moment arm thereby to change the resistive torque per unit spring force provided by the spring arrangement in support of the first support arm; a second support arm with a body portion, a proximal end pivotally coupled to the distal arm joint to pivot about a proximal pivot axis, and a distal end pivotally coupled to a second distal arm joint and further comprising a means for supporting an article relative to the second distal arm joint whereby the second support arm, the second distal arm joint, and the means for supporting an article relative to the second distal arm joint comprise the means for supporting the article relative to the distal end of the first support arm; a spring arrangement with a distal end coupled to the body portion of the second support arm and a proximal end pivotable about an effective pivot axis spaced a given distance from the proximal pivot axis of the second support arm to create a spring force moment arm of a given length whereby the spring arrangement will tend to provide a resistive torque in support of the second support arm against rotation in a given direction wherein the spring arrangement includes a spring member with a proximal end and a distal end and further comprising a means for altering the distance between the effective pivot axis of the spring arrangement and the proximal pivot axis of the second support arm during a pivoting of the second support arm to change the length of the spring force moment arm thereby to change the resistive torque per unit spring force provided by the spring arrangement in support of the second support arm; wherein the second support arm comprises a control arm that pivots about the proximal pivot axis of the second support arm and a disparate member that pivots relative to the proximal arm joint with the control arm and wherein the means for altering the distance between the effective pivot axis of the spring arrangement and the proximal pivot axis of the second support arm during a pivoting of the second support arm comprises a coupling of the proximal end of the spring arrangement to the disparate member.

Claim 21

An equipoise arm assembly for supporting an article in equipoise, the equipoise arm assembly comprising: a first support arm with a body portion with a proximal end and a distal end; a proximal arm joint pivotally coupled to the proximal end of the first support arm at a proximal pivot axis; a means for supporting an article relative to the distal end of the first support arm comprising a distal arm joint pivotally coupled to the distal end of the support arm at a distal pivot axis; a spring arrangement with a distal end coupled to the body portion of the first support arm and a proximal end pivotable about an effective pivot axis spaced a given distance from the proximal pivot axis to create a spring force moment arm of a given length whereby the spring arrangement will tend to provide a resistive torque in support of the first support arm against rotation in a given direction wherein the spring arrangement includes a spring member with a proximal end and a distal end; a means for altering the distance between the effective pivot axis of the spring arrangement and the proximal pivot axis of the first support arm during a pivoting of the first support arm to change the length of the spring force moment arm thereby to change the resistive torque per unit spring force provided by the spring arrangement in support of the first support arm; a second support arm with a body portion, a proximal end pivotally coupled to the distal arm joint to pivot about a proximal pivot axis, and a distal end pivotally coupled to a second distal arm joint and further comprising a means for supporting an article relative to the second distal arm joint whereby the second support arm, the second distal arm joint, and the means for supporting an article relative to the second distal arm joint comprise the means for supporting the article relative to the distal end of the first support arm; a spring arrangement with a distal end coupled to the body portion of the second support arm and a proximal end pivotable about an effective pivot axis spaced a given distance from the proximal pivot axis of the second support arm to create a spring force moment arm of a given length whereby the spring arrangement will tend to provide a resistive torque in support of the second support arm against rotation in a given direction wherein the spring arrangement includes a spring member with a proximal end and a distal end and further comprising a means for altering the distance between the effective pivot axis of the spring arrangement and the proximal pivot axis of the second support arm during a pivoting of the second support arm to change the length of the spring force moment arm thereby to change the resistive torque per unit spring force provided by the spring arrangement in support of the second support arm; wherein the second support arm comprises a control arm that pivots about the proximal pivot axis of the second support arm and a disparate member that pivots relative to the proximal arm joint with the control arm and wherein the means for altering the distance between the effective pivot axis of the spring arrangement and the proximal pivot axis of the second support arm during a pivoting of the second support arm comprises a coupling of the proximal end of the spring arrangement to the disparate member.

Claim 22

The equipoise arm assembly of claim 19 wherein the means for altering the distance between the effective pivot axis and the proximal pivot axis operates to decrease the distance between the effective pivot axis and the proximal pivot axis during a pivoting of the second support arm to decrease the length of the spring force moment arm.

Claim 23

An equipoise arm assembly for supporting an article in equipoise, the equipoise arm assembly comprising: a support arm with a body portion with a proximal end and a distal end; a proximal arm joint pivotally coupled to the proximal end of the support arm at a proximal pivot axis; a means for supporting an article relative to the distal end of the support arm; a spring arrangement with a distal end coupled to the body portion of the support arm and a proximal end pivotable about an effective pivot axis spaced a given distance from the proximal pivot axis to create a spring force moment arm of a given length whereby the spring arrangement will tend to provide a resistive torque in support of the support arm against rotation in a given direction wherein the spring arrangement includes a spring member with a proximal end and a distal end; and a means for altering the distance between the effective pivot axis of the spring arrangement and the proximal pivot axis of the support arm during a pivoting of the support arm to change the length of the spring force moment arm thereby to change the resistive torque per unit spring force provided by the spring arrangement in support of the support arm wherein the means for altering the distance between the effective pivot axis and the proximal pivot axis to change the length of the spring force moment arm creates a non-linear resistive torque pattern that corresponds more than a linear resistive torque pattern would to the non-linear torque pattern imparted on the proximal arm joint by the weights of the support aim and the article over a range of pivoting of the support arm and wherein the means for altering the distance between the effective pivot axis and the proximal pivot axis to change the length of the spring force moment arm alters the effective pivot axis of the spring arrangement to create a non-linear resistive torque pattern that generally corresponds to a pattern established by the following formula: T s =( W s +1.5 W a )· L ·sin α where T s is the torque imparted by the spring arrangement, W s is the cumulative weight of the article and any other elements supported by the support arm, W a is the weight of the support arm, L is the length of the support arm, and α is the angle between the support arm and vertical.

Claim 24

An equipoise arm assembly for supporting an article in equipoise, the equipoise arm assembly comprising: a support arm with a body portion with a proximal end and a distal end; a proximal arm joint pivotally coupled to the proximal end of the support arm at a proximal pivot axis; a means for supporting an article relative to the distal end of the support arm; a spring arrangement with a distal end coupled to the body portion of the support arm and a proximal end pivotable about an effective pivot axis spaced a given distance from the proximal pivot axis to create a spring force moment arm of a given length whereby the spring arrangement will tend to provide a resistive torque in support of the support arm against rotation in a given direction wherein the spring arrangement includes a spring member with a proximal end and a distal end; and a means for altering the distance between the effective pivot axis of the spring arrangement and the proximal pivot axis of the support arm during a pivoting of the support arm to change the length of the spring force moment arm thereby to change the resistive torque per unit spring force provided by the spring arrangement in support of the support arm wherein the means for altering the distance between the effective pivot axis and the proximal pivot axis to change the length of the spring force moment arm creates a non-linear resistive torque pattern that corresponds more than a linear resistive torque pattern would to the non-linear torque pattern imparted on the proximal arm joint by the weights of the support aim and the article over a range of pivoting of the support arm and wherein the means for altering the distance between the effective pivot axis and the proximal pivot axis to change the length of the spring force moment arm alters the effective pivot axis of the spring arrangement to create a non-linear resistive torque pattern that generally corresponds to a pattern established by the following formula: T s =( W s +1.5 W a )· L ·sin α where T s is the torque imparted by the spring arrangement, W s is the cumulative weight of the article and any other elements supported by the support arm, W a is the weight of the support arm, L is the length of the support arm, and α is the angle between the support arm and vertical.

Claim 25

An equipoise arm assembly for supporting an article in equipoise, the equipoise arm assembly comprising: a support arm with a body portion with a proximal end and a distal end; a proximal arm joint pivotally coupled to the proximal end of the support arm at a proximal pivot axis; a means for supporting an article relative to the distal end of the support arm; a spring arrangement with a distal end coupled to the body portion of the support arm and a proximal end pivotable about an effective pivot axis spaced a given distance from the proximal pivot axis to create a spring force moment arm of a given length whereby the spring arrangement will tend to provide a resistive torque in support of the support arm against rotation in a given direction wherein the spring arrangement includes a spring member with a proximal end and a distal end; and a means for altering the distance between the effective pivot axis of the spring arrangement and the proximal pivot axis of the support arm during a pivoting of the support arm to change the length of the spring force moment arm thereby to change the resistive torque per unit spring force provided by the spring arrangement in support of the support arm; wherein the support arm comprises a control arm that pivots about the proximal pivot axis and a disparate member that pivots relative to the proximal arm joint with the control arm and wherein the means for altering the distance between the effective pivot axis of the spring arrangement and the proximal pivot axis of the support arm during a pivoting of the support arm comprises a coupling of the proximal end of the spring arrangement to the disparate member.

Claim 26

An equipoise arm assembly for supporting an article in equipoise, the equipoise arm assembly comprising: a support arm with a body portion with a proximal end and a distal end; a proximal arm joint pivotally coupled to the proximal end of the support arm at a proximal pivot axis; a means for supporting an article relative to the distal end of the support arm; a spring arrangement with a distal end coupled to the body portion of the support arm and a proximal end pivotable about an effective pivot axis spaced a given distance from the proximal pivot axis to create a spring force moment arm of a given length whereby the spring arrangement will tend to provide a resistive torque in support of the support arm against rotation in a given direction wherein the spring arrangement includes a spring member with a proximal end and a distal end; and a means for altering the distance between the effective pivot axis of the spring arrangement and the proximal pivot axis of the support arm during a pivoting of the support arm to change the length of the spring force moment arm thereby to change the resistive torque per unit spring force provided by the spring arrangement in support of the support arm; wherein the support arm comprises a control arm that pivots about the proximal pivot axis and a disparate member that pivots relative to the proximal arm joint with the control arm and wherein the means for altering the distance between the effective pivot axis of the spring arrangement and the proximal pivot axis of the support arm during a pivoting of the support arm comprises a coupling of the proximal end of the spring arrangement to the disparate member.

Claim 27

The equipoise arm assembly of claim 22 wherein the means for altering the distance between the effective pivot axis and the proximal pivot axis operates to decrease the distance between the effective pivot axis and the proximal pivot axis during a pivoting of the support arm to decrease the length of the spring force moment arm.

Claim 28

The equipoise arm assembly of claim 23 wherein the disparate member comprises an arm housing that at least partially encases the control arm wherein the proximal end of the spring arrangement is pivotally coupled to the arm housing.

Claim 29

The equipoise arm assembly of claim 23 wherein the disparate member comprises an arm housing that at least partially encases the control arm wherein the proximal end of the spring arrangement is pivotally coupled to the arm housing.

Claim 30

The equipoise arm assembly of claim 25 wherein a parallelogram pivoting arrangement is established between the second support arm, the distal arm joint, and the second distal arm joint whereby the second distal arm joint will demonstrate parallel movement relative to the distal arm joint and relative to the proximal arm joint.

Claim 31

An equipoise arm assembly for supporting an article in equipoise, the equipoise arm assembly comprising: a support arm with a body portion with a proximal end and a distal end; a proximal arm joint pivotally coupled to the proximal end of the support arm at a proximal pivot axis; a means for supporting an article relative to the distal end of the support arm comprising a distal arm joint pivotally coupled to the distal end of the support arm at a distal pivot axis; a spring arrangement with a distal end coupled to the body portion of the support arm and a proximal end pivotable about an effective pivot axis spaced a given distance from the proximal pivot axis to create a spring force moment arm of a given length whereby the spring arrangement will tend to provide a resistive torque in support of the support arm against rotation in a given direction wherein the spring arrangement includes a spring member with a proximal end and a distal end wherein the spring arrangement includes a plurality of spaced coupling points for the spring member whereby the spring member can have any one of a variety of initial spring extensions whereby the spring arrangement can be adapted to provide support to articles of differing weights; and a means for altering the distance between the effective pivot axis of the spring arrangement and the proximal pivot axis of the support arm during a pivoting of the support arm to change the length of the spring force moment arm thereby to change the resistive torque per unit spring force provided by the spring arrangement in support of the support arm; wherein a parallelogram pivoting arrangement is established between the support arm and the proximal and distal arm joints whereby the distal arm joint will demonstrate parallel movement relative to the proximal arm joint wherein the parallelogram pivoting arrangement includes at least a first control arm and wherein the distal end of the spring arrangement is coupled to the first control arm.

Claim 32

An equipoise arm assembly for supporting an article in equipoise, the equipoise arm assembly comprising: a support arm with a body portion with a proximal end and a distal end; a proximal arm joint pivotally coupled to the proximal end of the support arm at a proximal pivot axis; a means for supporting an article relative to the distal end of the support arm comprising a distal arm joint pivotally coupled to the distal end of the support arm at a distal pivot axis; a spring arrangement with a distal end coupled to the body portion of the support arm and a proximal end pivotable about an effective pivot axis spaced a given distance from the proximal pivot axis to create a spring force moment arm of a given length whereby the spring arrangement will tend to provide a resistive torque in support of the support arm against rotation in a given direction wherein the spring arrangement includes a spring member with a proximal end and a distal end wherein the spring arrangement includes a plurality of spaced coupling points for the spring member whereby the spring member can have any one of a variety of initial spring extensions whereby the spring arrangement can be adapted to provide support to articles of differing weights; and a means for altering the distance between the effective pivot axis of the spring arrangement and the proximal pivot axis of the support arm during a pivoting of the support arm to change the length of the spring force moment arm thereby to change the resistive torque per unit spring force provided by the spring arrangement in support of the support arm; wherein a parallelogram pivoting arrangement is established between the support arm and the proximal and distal arm joints whereby the distal arm joint will demonstrate parallel movement relative to the proximal arm joint wherein the parallelogram pivoting arrangement includes at least a first control arm and wherein the distal end of the spring arrangement is coupled to the first control arm.

Claim 33

The equipoise arm assembly of claim 27 wherein the spring arrangement includes a slidable coupler coupled to the proximal arm joint and wherein the plurality of spaced coupling points are disposed on the slidable coupler for adjustably retaining the proximal end of the spring member.

Claim 34

The equipoise arm assembly of claim 28 further comprising a means for slidably coupling the slidable coupler to the first control arm.

Claim 35

An equipoise arm assembly for supporting an article in equipoise, the equipoise arm assembly comprising: a first support arm with a body portion with a proximal end and a distal end; a first arm joint pivotally coupled to the proximal end of the first support arm at a proximal pivot axis; a middle arm joint pivotally coupled to the distal end of the first support arm at a distal pivot axis; a first arm spring arrangement with a distal end coupled to the body portion of the first support arm and a proximal end pivotable about an effective pivot axis spaced a given distance from the proximal pivot axis of the first arm joint to create a spring force moment arm of a given length whereby the first arm spring arrangement will tend to provide a resistive torque in support of the first support arm against rotation in a given direction wherein the first arm spring arrangement includes a spring member with a proximal end and a distal end; a means for altering the distance between the effective pivot axis of the first arm spring arrangement and the proximal pivot axis of the first support arm during a pivoting of the first support arm to change the length of the spring force moment arm thereby to change the resistive torque per unit spring force provided by the first arm spring arrangement in support of the first support arm; a second support arm with a body portion, a proximal end pivotally coupled to the middle arm joint to pivot about a proximal pivot axis, and a distal end pivotally coupled to a second arm joint; a second arm spring arrangement with a distal end coupled to the body portion of the second support arm and a proximal end pivotable about an effective pivot axis spaced a given distance from the proximal pivot axis of the second support arm to create a spring force moment arm of a given length whereby the second arm spring arrangement will tend to provide a resistive torque in support of the second support arm against rotation in a given direction wherein the second arm spring arrangement includes a spring member with a proximal end and a distal end; and a means for altering the distance between the effective pivot axis of the second arm spring arrangement and the proximal pivot axis of the second support arm during a pivoting of the second support arm to change the length of the spring force moment arm thereby to change the resistive torque per unit spring force provided by the second arm spring arrangement in support of the second support arm wherein the means for altering the distance between the effective pivot axis of the first arm spring arrangement and the proximal pivot axis of the first support arm comprises a stop surface disposed adjacent to a portion of the first arm spring arrangement in combination with an open area adjacent to the stop surface wherein the first support arm can be pivoted through a given range of pivoting wherein the portion of the first spring arrangement will pivot through at least part of the open area until the portion of the first arm spring arrangement contacts the stop surface thereby to prevent further pivoting of at least part of the portion of the first arm spring arrangement whereby the effective pivot axis of the first arm spring arrangement and the spring force moment arm will be altered.

Claim 36

An equipoise arm assembly for supporting an article in equipoise, the equipoise arm assembly comprising: a first support arm with a body portion with a proximal end and a distal end; a first arm joint pivotally coupled to the proximal end of the first support arm at a proximal pivot axis; a middle arm joint pivotally coupled to the distal end of the first support arm at a distal pivot axis; a first arm spring arrangement with a distal end coupled to the body portion of the first support arm and a proximal end pivotable about an effective pivot axis spaced a given distance from the proximal pivot axis of the first arm joint to create a spring force moment arm of a given length whereby the first arm spring arrangement will tend to provide a resistive torque in support of the first support arm against rotation in a given direction wherein the first arm spring arrangement includes a spring member with a proximal end and a distal end; a means for altering the distance between the effective pivot axis of the first arm spring arrangement and the proximal pivot axis of the first support arm during a pivoting of the first support arm to change the length of the spring force moment arm thereby to change the resistive torque per unit spring force provided by the first arm spring arrangement in support of the first support arm; a second support arm with a body portion, a proximal end pivotally coupled to the middle arm joint to pivot about a proximal pivot axis, and a distal end pivotally coupled to a second arm joint; a second arm spring arrangement with a distal end coupled to the body portion of the second support arm and a proximal end pivotable about an effective pivot axis spaced a given distance from the proximal pivot axis of the second support arm to create a spring force moment arm of a given length whereby the second arm spring arrangement will tend to provide a resistive torque in support of the second support arm against rotation in a given direction wherein the second arm spring arrangement includes a spring member with a proximal end and a distal end; and a means for altering the distance between the effective pivot axis of the second arm spring arrangement and the proximal pivot axis of the second support arm during a pivoting of the second support arm to change the length of the spring force moment arm thereby to change the resistive torque per unit spring force provided by the second arm spring arrangement in support of the second support arm wherein the means for altering the distance between the effective pivot axis of the first arm spring arrangement and the proximal pivot axis of the first support arm comprises a stop surface disposed adjacent to a portion of the first arm spring arrangement in combination with an open area adjacent to the stop surface wherein the first support arm can be pivoted through a given range of pivoting wherein the portion of the first spring arrangement will pivot through at least part of the open area until the portion of the first arm spring arrangement contacts the stop surface thereby to prevent further pivoting of at least part of the portion of the first arm spring arrangement whereby the effective pivot axis of the first arm spring arrangement and the spring force moment arm will be altered.

Claim 37

The equipoise arm assembly of claim 30 wherein the second support arm comprises a control arm that pivots about the proximal pivot axis of the second support arm and a disparate member that pivots relative to the middle arm joint with the control arm and wherein the means for altering the distance between the effective pivot axis of the second arm spring arrangement and the proximal pivot axis of the second support arm during a pivoting of the second support arm comprises a coupling of the proximal end of the second arm spring arrangement to the disparate member.

Claim 38

The equipoise arm assembly of claim 31 wherein the means for altering the distance between the effective pivot axis of the second arm spring arrangement and the proximal pivot axis of the second support arm operates to decrease the distance between the effective pivot axis and the proximal pivot axis during a pivoting of the second support arm to decrease the length of the spring force moment arm.

Claim 39

equipoise arm assembly of claim 30 wherein the first arm spring arrangement includes a pivot link coupled to the first arm joint wherein the stop surface and the open area are disposed adjacent to the pivot link whereby the pivot link can be pivoted through a given range of pivoting until at least a portion of the pivot link makes contact with at least a portion of the stop surface whereby that at least a portion of the pivot link will be prevented from further pivoting whereby the effective pivot axis of the first arm spring arrangement and the spring force moment arm will be altered.

Claim 40

The equipoise arm assembly of claim 33 wherein the pivot link comprises a flexible member.

Claim 41

The equipoise arm assembly of claim 34 wherein the stop surface is variably sloped whereby the pivot link will progressively make increasing contact with the stop surface as the first support arm is pivoted thereby creating a moving effective pivot axis for the first arm spring arrangement.

Claim 42

The equipoise arm assembly of claim 33 wherein the first arm spring arrangement includes multiple rigid pivot links and wherein the stop surface is variably sloped whereby the pivot links will make sequential contact with the stop surface as the first support arm is pivoted thereby creating a moving effective pivot axis for the first arm spring arrangement.

Claim 43

The equipoise arm assembly of claim 30 wherein the open area comprises a pivot alcove in the first arm joint.

Claim 44

An equipoise arm assembly for supporting an article in equipoise, the equipoise arm assembly comprising: a first support arm with a body portion with a proximal end and a distal end; a first arm joint pivotally coupled to the proximal end of the first support arm at a proximal pivot axis; a middle arm joint pivotally coupled to the distal end of the first support arm at a distal pivot axis; a first arm spring arrangement with a distal end coupled to the body portion of the first support arm and a proximal end pivotable about an effective pivot axis spaced a given distance from the proximal pivot axis of the first arm joint to create a spring force moment arm of a given length whereby the first arm spring arrangement will tend to provide a resistive torque in support of the first support arm against rotation in a given direction wherein the first arm spring arrangement includes a spring member with a proximal end and a distal end; a means for altering the distance between the effective pivot axis of the first arm spring arrangement and the proximal pivot axis of the first support arm during a pivoting of the first support arm to change the length of the spring force moment arm thereby to change the resistive torque per unit spring force provided by the first arm spring arrangement in support of the first support arm; a second support arm with a body portion, a proximal end pivotally coupled to the middle arm joint to pivot about a proximal pivot axis, and a distal end pivotally coupled to a second arm joint; a second arm spring arrangement with a distal end coupled to the body portion of the second support arm and a proximal end pivotable about an effective pivot axis spaced a given distance from the proximal pivot axis of the second support arm to create a spring force moment arm of a given length whereby the second arm spring arrangement will tend to provide a resistive torque in support of the second support arm against rotation in a given direction wherein the second arm spring arrangement includes a spring member with a proximal end and a distal end; and a means for altering the distance between the effective pivot axis of the second arm spring arrangement and the proximal pivot axis of the second support arm during a pivoting of the second support arm to change the length of the spring force moment arm thereby to change the resistive torque per unit spring force provided by the second arm spring arrangement in support of the second support arm; wherein the second support arm comprises a control arm that pivots about the proximal pivot axis of the second support arm and a disparate member that pivots relative to the middle arm joint with the control arm and wherein the means for altering the distance between the effective pivot axis of the second arm spring arrangement and the proximal pivot axis of the second support arm during a pivoting of the second support arm comprises a coupling of the proximal end of the second arm spring arrangement to the disparate member.

Claim 45

An equipoise arm assembly for supporting an article in equipoise, the equipoise arm assembly comprising: a first support arm with a body portion with a proximal end and a distal end; a first arm joint pivotally coupled to the proximal end of the first support arm at a proximal pivot axis; a middle arm joint pivotally coupled to the distal end of the first support arm at a distal pivot axis; a first arm spring arrangement with a distal end coupled to the body portion of the first support arm and a proximal end pivotable about an effective pivot axis spaced a given distance from the proximal pivot axis of the first arm joint to create a spring force moment arm of a given length whereby the first arm spring arrangement will tend to provide a resistive torque in support of the first support arm against rotation in a given direction wherein the first arm spring arrangement includes a spring member with a proximal end and a distal end; a means for altering the distance between the effective pivot axis of the first arm spring arrangement and the proximal pivot axis of the first support arm during a pivoting of the first support arm to change the length of the spring force moment arm thereby to change the resistive torque per unit spring force provided by the first arm spring arrangement in support of the first support arm; a second support arm with a body portion, a proximal end pivotally coupled to the middle arm joint to pivot about a proximal pivot axis, and a distal end pivotally coupled to a second arm joint; a second arm spring arrangement with a distal end coupled to the body portion of the second support arm and a proximal end pivotable about an effective pivot axis spaced a given distance from the proximal pivot axis of the second support arm to create a spring force moment arm of a given length whereby the second arm spring arrangement will tend to provide a resistive torque in support of the second support arm against rotation in a given direction wherein the second arm spring arrangement includes a spring member with a proximal end and a distal end; and a means for altering the distance between the effective pivot axis of the second arm spring arrangement and the proximal pivot axis of the second support arm during a pivoting of the second support arm to change the length of the spring force moment arm thereby to change the resistive torque per unit spring force provided by the second arm spring arrangement in support of the second support arm; wherein the second support arm comprises a control arm that pivots about the proximal pivot axis of the second support arm and a disparate member that pivots relative to the middle arm joint with the control arm and wherein the means for altering the distance between the effective pivot axis of the second arm spring arrangement and the proximal pivot axis of the second support arm during a pivoting of the second support arm comprises a coupling of the proximal end of the second arm spring arrangement to the disparate member.

Claim 46

The equipoise arm assembly of claim 38 wherein the means for altering the distance between the effective pivot axis of the second arm spring arrangement and the proximal pivot axis of the second support arm operates to decrease the distance between the effective pivot axis and the proximal pivot axis during a pivoting of the second support arm to decrease the length of the spring force moment arm.

Claim 47

The equipoise arm assembly of claim 39 wherein the disparate member comprises an arm housing that at least partially encases the control arm wherein the proximal end of the second arm spring arrangement is pivotally coupled to the arm housing.