Article support stand

Claim 2

An article support stand comprising, a frame, a generally horizontal article support platform mounted on said frame for reciprocal vertical movement, said means including a lever pivotally mounted in said frame at a fixed pivot point, means operatively connected between said lever, frame and platform, for causing said lever to pivot about said fixed pivot point during vertical movement of said platform and resilient means mounted in said frame for extension is a straight line path in the direction of its axis only and being operatively connected between said frame and a predetermined point on said lever for applying a linearly varying force to said lever at a fixed point and at a fixed angle to the lever during movement of said platform, thereby to resiliently resist vertical movement of said platform in a first direction with a linearly varying torque and a constant weight to distance gradient; said resilient means applying a linearly varying bias to said lever to create therewith a moment force about said pivot point to resist said vertical movement of the article support platform in said first direction and said stand including means for selectively varying the point of application of said bias force to said lever, without varying the preload force of said spring, whereby the moment force resisting said vertical movement of said platform and the force gradient applied to said platform are selectively varied.

Claim 3

The article supporting stand as defined in claim 1 wherein said means for selectively varying the point of application of said bias force to said lever includes a first carriage mounted for movement along said lever and being operatively connected to said resilient means.

Claim 4

The article supporting stand as defined in claim 2 wherein said means for selectively varying the point of application of said bias force to said lever further includes means for selectively varying the location of said first carriage on said lever.

Claim 5

The article supporting stand as defined in claim 3 wherein said means for varying the location of said first carriage on said lever comprises a second carriage mounted in said frame for selective vertical movement and means operatively interconnecting said first and second carriages for moving said first carriage along said lever in response to vertical movement of said second carriage, said last mentioned means permitting pivotal movement of said lever in response to vertical movement of said platform and holding said first carriage in a relatively fixed position, during said pivotal movement whereby the point of application of said bias force to said lever remains substantially constant during pivotal movement of said lever.

Claim 6

The article supporting stand as defined in claim 4 wherein said resilient means includes a spring, a flexible cable connected at one end to said spring and at its opposite end to said second carriage and a plurality of rollers defining a path of travel for said last mentioned cable, including a first roller mounted on said first carriage and a second roller mounted on said second carriage, said last mentioned cable being guided from its point of connection with said second carriage over said roller and then over said second roller to its point of connection with said spring whereby the initial load on said spring is uneffected by the position of said second carriage.

Claim 7

The article supporting stand as defined in claim 5 wherein said means for operatively interconnecting said first and second carriages includes a flexible reference cable operatively connected at its opposite ends to said first and second carriages and at least two rollers defining a path of travel for said reference cable and including a first roller mounted for rotation about said pivot point and a second roller mounted on said lever, at a position wherein said first carriage is between it and said second pivot point, said reference cable being guided from its point of connection with said first carriage over said second roller and thence over said first roller to said second carriage, whereby said first carriage moves along said lever in response to vertical movement of said second carriage, a distance equal to the distance moved by said second carriage.

Claim 8

The article supporting stand as defined in claim 6 wherein said means for causing said lever to pivot comprises at least one cable operatively associated with said lever and connected at one end to said platform and at its other to said frame.

Claim 9

The article supporting stand as defined in claim 7 wherein said means for causing said lever to pivot comprises at least two flexible cables respectively connected at one end to a common point on said frame and connected at their opposite ends to opposite sides of said platform and a plurality of guide rollers including a pair of rollers mounted on said lever for respectively engaging and reversing the direction of said last mentioned cables between their ends whereby, for every two inches of vertical movement of said platform, said rollers move with said lever at most only one inch, as said lever pivots about its pivot point.

Claim 10

The arTicle supporting stand as defined in claim 8 wherein said platform is mounted in said frame adjacent only one edge thereof and extends from said frame as a cantilever and said lever is mounted in said frame for pivotal movement in a vertical plane located beyond said one edge of said platform to permit said platform to move vertically with respect thereto.

Claim 11

An article support stand comprising a generally vertically extending frame, an article support platform mounted at one end in said frame for reciprocal vertical movement between upper and lower positions on said frame and extending horizontally outward of each frame as a cantilever, and means for resiliently supporting said platform on said frame and for biasing said platform towards its uppermost position, and means including a lever pivotally mounted in said frame at a fixed pivot point for pivotal movement in a vertical plane, a first pair of flexible cables respectively connected at one end to a common point on said frame and connected at their opposite ends to opposite sides of said platform adjacent said one end thereof, a plurality of guide rollers mounted in said frame over which said first pair of cables are guided between their ends including a pair of rollers mounted on said lever for respectively engaging and reversing the direction of said cables between their ends whereby vertical movement of said platform between its upper and lowermost positions causes said lever to pivot about its pivot point; means for applying a biasing force to said lever to create therewith a moment force about said pivot point which resists downward movement of said platform and normally urges said platform towards its upper position, said biasing means including a first carriage mounted for movement along said lever, and a spring operatively connected to said carriage for applying said bias force to said lever in a predetermined direction to resist downward movement of said platform; and means for selectively varying the location of said first carriage along said lever, thereby to vary selectively the point of application of said biasing force to said lever; said means for varying the location of said first carriage on said lever comprising a second carriage mounted in said frame for selective vertical movement, a flexible reference cable operatively connected at its opposite ends to said first and second carriages, a first roller mounted in said frame below said second carriage, a second roller mounted for rotation about said pivot point and a third roller mounted on said lever at a position wherein said first carriage is between said pivot point and said third roller, said reference cable being guided from its point of connection with said second carriage sequentially over said first through third rollers to its point of connection with said first carriage whereby said first carriage moves along said lever, in response to vertical movement of said second carriage, a distance equal to the distance moved by said second carriage.

Claim 12

An article support stand comprising a generally vertically extending frame, an article support platform mounted at one end in said frame for reciprocal vertical movement between upper and lower positions on said frame and extending horizontally outward of each frame as a cantilever, and means for resiliently supporting said platform on said frame and for biasing said platform towards its uppermost position, and means including a lever pivotally mounted in said frame at a fixed pivot point for pivotal movement in a vertical plane, a first pair of flexible cables respectively connected at one end to a common point on said frame and connected at their opposite ends to opposite sides of said platform adjacent said one end thereof, a plurality of guide rollers mounted in said frame over which said first pair of cables are guided between their ends including a pair of rollers mounted on said lever for respectively engaging and reversing the direction of said cables between their ends whereby vertical movement of said platform between its upper and lowermost positions causes said lever to pivot about its pivot point; means for applying a biasing force to said lever to create therewith a moment force about said pivot point which resists downward movement of said platform and normally urges said platform towards its upper position, said biasing means including a first carriage mounted for movement along said lever, and a spring operatively connected to said carriage for applying said bias force to said lever in a predetermined direction to resist downward movement of said platform; and means for selectively varying the location of said first carriage along said lever, thereby to vary selectively the point of application of said biasing force to said lever; said means for varying the location of said first carriage on said lever comprising a second carriage mounted in said frame for selective vertical movement, a flexible reference cable operatively connected at its opposite ends to said first and second carriages, a first roller mounted in said frame below said second carriage, a second roller mounted for rotation about said pivot point and a third roller mounted on said lever at a position wherein said first carriage is between said pivot point and said third roller, said reference cable being guided from its point of connection with said second carriage sequentially over said first through third rollers to its point of connection with said first carriage whereby said first carriage moves along said lever, in response to vertical movement of said second carriage, a distance equal to the distance moved by said second carriage.

Claim 13

The article supporting stand as defined in claim 10 including a flexible cable operatively connected at its opposite ends to said spring and said second carriage, a first guide roller mounted on said first carriage, a second guide roller mounted on said second carriage, and a third guide roller mounted in said frame, below said second carriage, in vertical alignment with said second guide roller, said last mentioned flexible cable being guided from its point of connection with said second carriage over said guide roller on said first carriage, thence over the guide on said second carriage and the third guide roller on said frame to its point of connection with said spring, whereby said spring is operatively connected to said first carriage to apply said bias force to said lever and said bias force is substantially uneffected by the position of said first and second carriages.

Claim 14

The article support stand as defined in claim 11 including a threaded actuating rod mounted in said frame and threAdedly engaged with said second carriage, whereby rotation of said rod selectively varies the vertical position of said second carriage in said frame, thereby to vary the location of said first carriage on said lever.

Claim 15

An article support stand comprising, a frame, a generally horizontal article support platform mounted on said frame for reciprocal movement between upper and lower positions on said frame, and means for resiliently supporting said platform on said frame and for biasing said platform towards its uppermost position, said means including a lever pivotally mounted in said frame, means operatively connected between said lever, frame and platform for causing said lever to pivot, means for applying a biasing force to said lever to create therewith a moment force which resists downward movement of said platform and normally urges said platform towards its upper position, said biasing means including a first carriage mounted for movement along said lever and a spring operatively connected between said frame and said first carriage to apply said biasing force to said lever in a predetermined direction to resist downward movement of said platform; a second carriage mounted in said frame for selective vertical movement with respect thereto, and means, operatively interconnecting said first and second carriages and said spring, for varying the location of said first carriage on said lever in response to vertical movement of said second carriage and for holding said first carriage in a fixed position on the lever during pivotal movement thereof, without effecting the bias force applied to said lever, whereby the moment force resisting vertical movement of said platform may be selectively varied by selected movement of said second carriage.

Claim 16

An article support stand comprising, a frame, a generally horizontal article support platform mounted on said frame for reciprocal movement between upper and lower positions on said frame, and means for resiliently supporting said platform on said frame and for biasing said platform towards its uppermost position, said means including a lever pivotally mounted in said frame, means operatively connected between said lever, frame and platform for causing said lever to pivot, means for applying a biasing force to said lever to create therewith a moment force which resists downward movement of said platform and normally urges said platform towards its upper position, said biasing means including a first carriage mounted for movement along said lever and a spring operatively connected between said frame and said first carriage to apply said biasing force to said lever in a predetermined direction to resist downward movement of said platform; a second carriage mounted in said frame for selective vertical movement with respect thereto, and means, operatively interconnecting said first and second carriages and said spring, for varying the location of said first carriage on said lever in response to vertical movement of said second carriage and for holding said first carriage in a fixed position on the lever during pivotal movement thereof, without effecting the bias force applied to said lever, whereby the moment force resisting vertical movement of said platform may be selectively varied by selected movement of said second carriage.

Claim 17

The article support stand as defined in claim 13 wherein said means for varying the location of said first carriage on said lever includes a flexible reference cable operatively connected at its opposite ends to said first and second carriages, a first roller mounted in said frame below said second carriage, a second roller mounted for rotation about the pivotal axis of said lever and a third roller mounted on said lever at a position wherein said first carriage is between said pivot point and said third roller, said reference cable being guided from its point of connection with said second carriage sequentially over said first through third rollers to its point of connection with said first carriage whereby said first carriage moves along said lever, in response to vertical movement of said second carriage, a distance equal to the distance moved by said second carriage; and a second flexible cable operatively connected at its opposite ends to said spring and said second carriage, a first guide roller mounted on said first carriage, a second guide roller mounted on said second carriage, and a third guide roller mounted in said frame below said second carriage in vertical alignment with said second guide roller, said last mentioned flexible cable being guided from its point of connection with said second carriage over said guide roller on said first carriage and thence over the guide roller on said second carriage and the third guide roller on said frame to its point of connection with said spring, whereby said spring is operatively connected to said first carriage to apply said bias force to said lever and said bias force is substantially uneffected by the position of said first and second carriages.

Claim 18

The article support stand as defined in claim 14 including a threaded actuating rod mounted in said frame and threadedly engaged with said second carriage, whereby rotation of said rod selectively varies the vertical position of said second carriage in said frame, thereby to vary the location of said first carriage on said lever.