Force transducer

Claim 2

A load transducer comprising; an elongate elastic load carrying beam having a reduced waist portion formed intermediate its ends, the longitudinal axis of said beam extending centrally through said waist portion of said beam; said beam having a hole formed at the waist portion and extending through said beam, the axis of said hole being disposed normally to the longitudinal axis of said load carrying beam; and means supporting said beam at one end thereof to receive a force applied thereto in a direction normal to the plane defining said lonGitudinal axis of said beam and said central axis of said hole to thereby impart a bending stress to said beam along its length, said waist portion being in the unsupported part of said beam, said bending stress being concentrated at said waist portion and strain gage means associated with the inner perimetric surface of said hole to determine the magnitude of said force.

Claim 3

A device as claimed in Claim 1 further comprising: plug means covering each end of said hole to isolate said hole and sensing means contained therein from the ambient atmosphere, said plug means being formed from a readily yieldable material so as not to affect appreciably the resilience of said load carrying member.

Claim 4

A device as claimed in Claim 1 wherein said reduced waist portion is defined by a pair of opposed concave surfaces formed on said load carrying member, the axis of said hole being disposed between said surfaces at the most narrow region of said waist portion.

Claim 5

A device as claimed in Claim 3 further comprising: plug means covering each end of said hole to isolate said hole and said sensing means contained therein from the ambient environment, said plug means being formed from a readily yieldable material so as not to affect appreciably the resilience of said load carrying member.

Claim 6

A device as defined in Claim 1 further comprising: plug means covering each end of said hole to isolate said hole and said sensors contained therein from the ambient environment; and means for fastening said plug means to said load carrying beam said fastening means being located at the neutral axis of said beam so as not to interfere with the structural characteristics of said beam.

Claim 7

A device as claimed in Claim 3 further comprising; plug means covering each end of said hole to isolate said hole and strain gage means contained therein from the ambient environment; and means for fastening said plug means to said load carrying beam, said fastening means being located at the neutral axis of said beam so as not to interfere with the structural characteristics of said beam.

Claim 8

A device as defined in Claim 6 wherein said plug means further includes: an electrical outlet mounted thereon.

Claim 9

A transducer as defined in Claim 1 further comprising: said beam having notches formed at the internal perimetric surface of said hole in the regions of maximum stress concentration thereby to further increase the stress concentration in said regions, said strain gage means being nested within said notches to mechanically protect said strain gage means.

Claim 10

A load transducer comprising: an elongate elastic load carrying beam having a reduced waist portion formed intermediate its ends, said reduced waist portion being formed symmetrically about the longitudinal axis of said beam; said beam having a hole formed at said waist portion and extending through said beam, the axis of said hole being disposed normally and in intersecting relation to the longitudinal axis of said beam; means for supporting rigidly one end of said beam whereby when a force is applied to said beam along a direction that is normal to the plane defined by the longitudinal axis of said beam and the central axis of said hole said force may apply a bending stress to said beam, the resultant strain being concentrated at said reduced waist portion; and means for varying the longitudinal spacing at which said beam is supported thereby to control the strain at said waist portion whereby the sensitivity of said transducer may be varied.

Claim 11

A load transducer comprising: an elongate elastic load carrying beam having a reduced waist portion formed intermediate its ends, said reduced waist portion being formed symmetrically about the longitudinal axis of said beam; said beam having a hole formed at said waist portion and extending through said beam, the axis of said hole being disposed normally and in intersecting relation to the longitudinal axis of said beam; means for supporting rigidly one end of said beam whereby when a force is applied to said beam along a direction that is normal to the plane defined by the longitudinal axis of said beam and the central axis of said hole said force may apply a bending stress to said beam, the resultant strain being concentrated at said reduced waist portion; and means for varying the longitudinal spacing at which said beam is supported thereby to control the strain at said waist portion whereby the sensitivity of said transducer may be varied.

Claim 14

A method as claimed in claim 10 wherein said strain at the interior perimetric surface of said hole is measured at a location most distant from said longitudinal axis of said beam.

Claim 15

A transducer as defined in claim 1 further comprising: said beam having notches formed at the internal perimetric surface of said hole in the regions of maximum stress concentration thereby to further increase the stress concentration in said regions, said strain gage means being nested within said notches to mechanically protect said strain gage means

Claim 16

A pillow block transducer for supporting a shaft rotatable within a pillow block comprising: an elongate, elastic, load-carrying beam having a reduced waist portion formed intermediate its ends, said reduced waist portion being formed symmetrically about the longitudinal axis of said beam; said member having a hole formed at said waist portion and extending through said beam, the axis of said hole being disposed normally and at intersecting relation to the longitudinal axis of said beam; means for supporting rigidly one end of said beam whereby when a force is applied to the other end of said beam along a direction that is normal to the plane defined by the longitudinal axis of said beam and the central axis of said hole, said force will apply a bending stress to said beam, the resultant strain being concentrated at said reduced waist portion; strain gage means operatively associated with the internal perimetric surface of said hole and being so constructed and arranged as to provide an indication of the magnitude of strain generated at said reduced waist portion; means mounting said pillow block to the free, other end of said beam.

Claim 17

A pillow block transducer for supporting a shaft rotatable within a pillow block comprising: an elongate, elastic, load-carrying beam having a reduced waist portion formed intermediate its ends, said reduced waist portion being formed symmetrically about the longitudinal axis of said beam; said member having a hole formed at said waist portion and extending through said beam, the axis of said hole being disposed normally and at intersecting relation to the longitudinal axis of said beam; means for supporting rigidly one end of said beam whereby when a force is applied to the other end of said beam along a direction that is normal to the plane defined by the longitudinal axis of said beam and the central axis of said hole, said force will apply a bending stress to said beam, the resultant strain being concentrated at said reduced waist portion; strain gage means operatively associated with the internal perimetric surface of said hole and being so constructed and arranged as to provide an indication of the magnitude of strain generated at said reduced waist portion; means mounting said pillow block to the free, other end of said beam.

Claim 18

A transducer as defined in Claim 13 further comprising: means for varying, lengthwise of said transducer, the position at which said pillow block is mounted to said free other end of said transducer.

Claim 19

A torque responsive transducer comprising: a pair of elongate, elastic, load-carrying beams, each of said beams having a reduced waist portion formed intermediate its ends, said reduced waist portions being formed symmetrically about the longitudinal axis of said beam; each of said members having a hole formed at said waist portion and extending through said beam, the axis of each of said holes being disposed normally and in intersecting relation to the longitudinal axis of its associated beam; means for supporting rigidly one end of each of said beams so that the longitudinal axes of said beams are parallel to each other; a transmission plate extending normally to the axes of said beams, the ends of said transmission plate being secured to the other, free end of each beams, whereby a torque applied to said transmission plate between said beams will cause said beams to bend in predetermined directions; and means for sensing the magnitude of strain generated at the internal perimetric surface of each of said holes.

Claim 20

A torque responsive transducer comprising: a pair of elongate, elastic, load-carrying beams, each of said beams having a reduced waist portion formed intermediate its ends, said reduced waist portions being formed symmetrically about the longitudinal axis of said beam; each of said members having a hole formed at said waist portion and extending through said beam, the axis of each of said holes being disposed normally and in intersecting relation to the longitudinal axis of its associated beam; means for supporting rigidly one end of each of said beams so that the longitudinal axes of said beams are parallel to each other; a transmission plate extending normally to the axes of said beams, the ends of said transmission plate being secured to the other, free end of each beams, whereby a torque applied to said transmission plate between said beams will cause said beams to bend in predetermined directions; and means for sensing the magnitude of strain generated at the internal perimetric surface of each of said holes.

Claim 21

A transducer as defined in claim 1 wherein said sensing means comprises: at least two electrodes; means mounting said at least two electrodes, in insulative relation, to the internal perimetric surface of said hole with a space defined between said at least two electrodes, said electrodes being oriented such that said space therebetween will vary in response to flexure of said transducer, whereby when an electric potential is applied across said electrodes the capacitance therebetween may vary in response to said flexure of said transducer.

Claim 22

A transducer as defined in claim 16 wherein said elEctrodes comprise: a first, ground electrode extending into said hole in a direction substantially normal to the longitudinal axis of said load carrying member; a second electrode on one side of and spaced from said first electrode; and a third electrode on the other side of and spaced from said first electrode.

Claim 23

A transducer as defined in claim 16 wherein said electrodes comprise: at least three wedge-shaped electrodes mounted to the internal surface of said hole so that adjacent side edges of adjacent wedges define a space therebetween, whereby flexure of said load carrying column may effect dimensional variation of said spaces.

Claim 24

A transducer as defined in Claim 18 wherein said insulative mounting comprises: a insulative ring secured to the internal perimetric surface of said hole; said wedge-shaped electrodes being mounted to the internal perimetric surface of said ring.

Claim 25

A load transducer comprising: an elongate elastic load carrying beam of circular cross section having a reduced waist portion formed intermediate its ends, the longitudinal axis of said beam extending centrally through said waist portion of said beam; said beam having a hole formed at the waist portion and extending through said beam, the axis of said hole being disposed normal to the longitudinal axis of said beam; and means supporting said beam to receive a torsional force applied thereto in a direction around the longitudinal axis of said beam to thereby impart a torsional stress to said beam, said torsional stress being concentrated at said waist portion, and strain gages associated with the inner perimetric surface of said hole to determine the magnitude of said force.

Claim 26

A load transducer comprising: an elongate elastic load carrying beam of circular cross section having a reduced waist portion formed intermediate its ends, the longitudinal axis of said beam extending centrally through said waist portion of said beam; said beam having a hole formed at the waist portion and extending through said beam, the axis of said hole being disposed normal to the longitudinal axis of said beam; and means supporting said beam to receive a torsional force applied thereto in a direction around the longitudinal axis of said beam to thereby impart a torsional stress to said beam, said torsional stress being concentrated at said waist portion, and strain gages associated with the inner perimetric surface of said hole to determine the magnitude of said force.

Claim 27

A transducer as defined in claim 20 further comprising: means orienting said strain gages diagonally within said hole to increase the sensitivity of said transducer to torsional stresses applied thereto.