Load sensor for a human hand
First Claim
1. A load sensor apparatus for a human hand and digits thereof for determining loads exerted between two portions of such hand comprising a sensor including a body, said body having a base portion and a reference platform fixably mounted to said base to provide for engagement with one portion of a hand to be tested;
- said body having a movable block portion, and flexure members connecting said movable block portion to said base of said body, and a movable platform mounted on said block portion and positioned adjacent said reference platform whereby two portions of a hand to be tested can engage the reference platform and movable platform at the same time and cause movement of the movable platform toward the reference platform, and means for measuring the movement of the movable block portion relative to the base portion of the body.
1 Assignment
0 Petitions
Accused Products
Abstract
A human hand load sensor is a strain gauge based force measurement instrument that has two platforms or handles that can be moved together with parts of the human hand, for example, a thumb and finger, or the handles can be grasped between the heel of the hand and several fingers. The instrument permits very precise measuring of strength force by supporting a movable handle relative to a base or reference handle through a flexure system which deforms predictably under shear loading as the handles or platforms are moved together. The flexure system is much like a parallel linkages made from a single block of material between a base and a movable block, and having a small deflecting beam sensing element between the base and the movable block that is isolated from influences of bending or rolling movements on the strain level. The strain energy is sensed with strain gauges that provide a signal directly proportional to the shear loading for very accurate measurements. The making of the base and movable block portions from a single block of material eliminates assembly joints, giving a greater repeatability, high linearity, less zero shift during use, less hysteresis, and more stable calibration coefficients. Further, the machining process or manufacturing process is relatively low cost and highly accurate. The one piece body is easy to calibrate. The base or platform size can be modified quite easily for a wide variety of uses.
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Citations
13 Claims
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1. A load sensor apparatus for a human hand and digits thereof for determining loads exerted between two portions of such hand comprising a sensor including a body, said body having a base portion and a reference platform fixably mounted to said base to provide for engagement with one portion of a hand to be tested;
- said body having a movable block portion, and flexure members connecting said movable block portion to said base of said body, and a movable platform mounted on said block portion and positioned adjacent said reference platform whereby two portions of a hand to be tested can engage the reference platform and movable platform at the same time and cause movement of the movable platform toward the reference platform, and means for measuring the movement of the movable block portion relative to the base portion of the body.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An assembly for measuring loads comprising a unitary block of material, said unitary block having a base portion partially separated from a movable portion of said unitary block by a slot, said base portion having a first platform, and said movable portion of said unitary block having a second platform, said second platform being adjacent to and separated from said first platform by said slot, opening means formed on the movable portion of the unitary block to form first and second block portions and to form a flexure joining the first and second block portions, the flexure comprising spaced apart links, each joined to the first and second block portions through integral hinge sections, and an integral beam positioned between the links and joined to the first and second block portions, the beams deflecting from shear loading when the first and second block portions are moved relative to each other, when a loading is applied to said platforms causing said platforms to deflect towards each other, and means for sensing deflection of the integral beam.
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12. A load sensor apparatus for a hand and digits thereof for determining loads exerted between two relatively movable portions of such hand comprising a sensor including a body, said body having a base portion, support means on the base portion to provide for engagement with one portion of a hand to be tested;
- said body having a movable block portion, flexure members connecting said movable block portion to said base portion of said body, a platform mounted on said block portion and positioned to receive a second portion of a hand to be tested when one portion is engaging the support means so that gripping between the two portions causes movement of the platform toward the support means and means for measuring the movement of the moveable block portion relative to the base portion of the body.
- View Dependent Claims (13)
Specification