Gem grinder with approach control means

Claim 2

A gem cutting and polishing machine, comprising: a. a base; b. a flat rotatable disc or lap, mounted upon the base, for mounting selectable abrasive surfaces; c. a pivot body support structure, mounted upon the base, comprising in turn; 1. a pivot shaft with axis parallel to the lap plane; 2. an ultimate stop structure; 3. a structure which supports the ultimate stop structure and pivot shaft, and which can be adjusted to control the height of the pivot shaft above the lap and the angle between the lap plane and an axis running from the pivot shaft to the ultimate stop structure; d. a pivot body, mounted rotatably upon the pivot shaft in such a way that its rotation in one or both directions past a certain point is blocked by the ultimate stop structure; e. a dop, mounted in part within the pivot body, rotatable about an axis normal to the axis of the pivot shaft, and having at one end a structure to firmly grip the gem stone to be cut or polished; f. a sensor to detect and to signal the concluding motions of the pivot body or dop as it approaches and finally contacts the ultimate stop structure; g. electrical circuitry to transfer the sensor signals to a signalling device h. a signalling device to present to the user of the machine information such as the force being applied to the gem, the rate of cutting, or the distance remaining before a desired surface or shape of the gem is reached.

Claim 3

an ultimate stop structure;

Claim 4

an ultimate stop structure;

Claim 5

A gem cutting and polishing machine, as claimed in claim 1, wherein the sensor is comprised of one or more strain gages.

Claim 6

a structure which supports the ultimate stop structure and pivot shaft, and which can be adjusted to control the height of the pivot shaft above the lap and the angle between the lap plane and an axis running from the pivot shaft to the ultimate stop structure; d. a pivot body, mounted rotatably upon the pivot shaft in such a way that its rotation in one or both directions past a certain point is blocked by the ultimate stop structure; e. a dop, mounted in part within the pivot body, rotatable about an axis normal to the axis of the pivot shaft, and having at one end a structure to firmly grip the gem stone to be cut or polished; f. a sensor to detect and to signal the concluding motions of the pivot body or dop as it approaches and finally contacts the ultimate stop structure; g. electrical circuitry to transfer the sensor signals to a signalling device h. a signalling device to present to the user of the machine information such as the force being applied to the gem, the rate of cutting, or the distance remaining before a desired surface or shape of the gem is reached.

Claim 7

a structure which supports the ultimate stop structure and pivot shaft, and which can be adjusted to control the height of the pivot shaft above the lap and the angle between the lap plane and an axis running from the pivot shaft to the ultimate stop structure; d. a pivot body, mounted rotatably upon the pivot shaft in such a way that its rotation in one or both directions past a certain point is blocked by the ultimate stop structure; e. a dop, mounted in part within the pivot body, rotatable about an axis normal to the axis of the pivot shaft, and having at one end a structure to firmly grip the gem stone to be cut or polished; f. a sensor to detect and to signal the concluding motions of the pivot body or dop as it approaches and finally contacts the ultimate stop structure; g. electrical circuitry to transfer the sensor signals to a signalling device h. a signalling device to present to the user of the machine information such as the force being applied to the gem, the rate of cutting, or the distance remaining before a desired surface or shape of the gem is reached.

Claim 8

A gem cutting and polishing machine, as claimed in claim 1, wherein the sensor comprises a flexible, longitudinal member, affixed at or near one end to the pivot body support structure and situated so as to be contacted and flexed by a portion of the pivot body or of the dop during the concluding movements of the pivot body or dop leading up to the pivot body or dop contacting the ultimate stop structure, and a plurality of strain gages attached to the flexible member to detect and signal deflections of the member.

Claim 9

A gem cutting and polishing machine, as claimed in claim 1, wherein the sensor is comprised of one or more proximity sensors.

Claim 10

A gem cutting and polishing machine, as claimed in claim 1, wherein the sensor is comprised of a proximity sensor, secured to the pivot body support structure, and situated so as to be approached and finally contacted by a magnetized portion of the pivot body or dop or by a magnet affixed to the pivot body or dop, as the pivot body or dop approaches and finally contacts the ultimate stop structure.

Claim 11

A gem cutting and polishing machine, comprising: a. a horizontal base; b. a flat, rotatable disc or lap, mounted upon and parallel to the base, for mounting selectable abrasive surfaces; c. a vertical adjustment support subassembly, substantially longitudinal in shape, mounted upon the base with longitudinal axis normal to the base, adjustable in position on the base in directions parallel to the bAse plane, and finely adjustable in height above the base plane; d. a protractor support member, slidably mounted on the vertical adjustment support subassembly; e. a protractor, consisting of a circular segment mounted by means of the protractor support member in a plane normal to the base plane; f. a saddle block, mounted slidably upon the protractor, a portion of said saddle block serving as an ultimate stop structure; g. a pivot shaft, mounted upon the saddle block, with the axis of the pivot shaft parallel to the base plane; h. a pivot body, mounted rotatably upon the pivot shaft in such a way that its rotation in one or both directions past a certain point is blocked by the ultimate stop structure; i. a dop, mounted in part within the pivot body, rotatable about an axis normal to the axis of the pivot shaft, and having at one end a structure to firmaly grip the gem stone to be cut or polished; j. a sensor to detect and to signal the concluding motions of the pivot body or dop as it approaches and finally contacts the ultimate stop structure; k. electrical circuitry to transfer the sensor signals to a signalling device l. a signalling device to present to the user of the machine information such as the force being applied to the gem, the rate of cutting, or the distance remaining before a desired surface or shape of the gem is reached.

Claim 12

A gem cutting and polishing machine, comprising: a. a horizontal base; b. a flat, rotatable disc or lap, mounted upon and parallel to the base, for mounting selectable abrasive surfaces; c. a vertical adjustment support subassembly, substantially longitudinal in shape, mounted upon the base with longitudinal axis normal to the base, adjustable in position on the base in directions parallel to the bAse plane, and finely adjustable in height above the base plane; d. a protractor support member, slidably mounted on the vertical adjustment support subassembly; e. a protractor, consisting of a circular segment mounted by means of the protractor support member in a plane normal to the base plane; f. a saddle block, mounted slidably upon the protractor, a portion of said saddle block serving as an ultimate stop structure; g. a pivot shaft, mounted upon the saddle block, with the axis of the pivot shaft parallel to the base plane; h. a pivot body, mounted rotatably upon the pivot shaft in such a way that its rotation in one or both directions past a certain point is blocked by the ultimate stop structure; i. a dop, mounted in part within the pivot body, rotatable about an axis normal to the axis of the pivot shaft, and having at one end a structure to firmaly grip the gem stone to be cut or polished; j. a sensor to detect and to signal the concluding motions of the pivot body or dop as it approaches and finally contacts the ultimate stop structure; k. electrical circuitry to transfer the sensor signals to a signalling device l. a signalling device to present to the user of the machine information such as the force being applied to the gem, the rate of cutting, or the distance remaining before a desired surface or shape of the gem is reached.

Claim 13

A gem cutting and polishing machine, as claimed in claim 6, wherein the sensor is comprised of one or more strain gages.

Claim 14

A gem cutting and polishing machine, as claimed in claim 6, wherein the sensor comprises a flexible, longitudinal member, affixed at or near one end to the pivot body support structure and situated so as to be contacted and flexed by a portion of the pivot body or of the dop during the concluding movements of the pivot body or dop leading up to the pivot body or dop contacting the ultimate stop structure, and a plurality of strain gages attached to the flexible member to detect and signal deflections of the member.

Claim 15

A gem cutting and polishing machine, as claimed in claim 6, wherein the sensor is comprised of one or more proximity sensors.

Claim 16

A gem cutting and polishing machine, as claimed in claim 6, wherein the sensor is comprised of a proximity sensor, secured to the pivot body support structure, and situated so as to be approached and finally contacted by a magnetized portion of the pivot body or dop or by a magnet affixed to the pivot body or dop, as the pivot body or dop approaches and finally contacts the ultimate stop structure.