Mass-produced flat multiple-beam load cell and scales incorporating it
First Claim
1. A low-profile load cell which comprises:
- a. a flat metal plate having a generally uniform horizontal cross-section comprising;
(1) a load-receiving member comprising a first transverse section integral with a load-receiving tongue, the load-receiving tongue arranged symmetrically about a north-south axis of the plate, extending across an east-west axis of the plate, and receiving the load to be measured over an area symmetrical about the north-south and east-west axes;
(2) a clamping member comprising a second transverse section opposed from the first transverse section across the east-west axis, the clamping member further comprising a pair of clamping tongues integral with the second transverse member and extending across the east-west axis, each camping tongue being symmetrical to the other with respect to the north-south axis; and
(3) two flexure beams extending across the east-west axis and connecting the first and second transverse sections of the metal plate, a first half of each flexure beam symmetrical to a second half about the east-west axis, and the flexure beams symmetrical to each other about the north-south axis; and
b. a pair of strain transducers mounted on each flexure beam with each sensor equi-distant from the east-west axis;
wherein, when a load is applied to the load-receiving element the flexure beams each bend into a symmetrical double-cantilever S-shape, and each transducer in each transducer pair produces an electronic signal equal and opposite to the other transducer in the transducer pair.
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Accused Products
Abstract
This invention is a mass-produced, flat, multiple-beam load cell for use in weighing devices. This load cell is particularly suited to very low-profile scales incorporating a plurality of load cells. It is made from a flat piece of metal and includes: (1) a load-receiving member having a transverse section integral with a load-receiving tongue symmetrical about a north-south axis of the plate, which reach across an east-west axis of the plate; (2) a clamping member having a transverse section and possibly a pair of clamping tongues which reach across the east-west axis; and (3) two flexure beams connecting the two transverse sections of the metal plate, each beam symmetrical about the east-west axis, and the beams symmetrical about the north-south axis. When a load is applied to the load-receiving tongue: (1) the flexure beams bend into symmetrical double-cantilever S-shapes, with equal and opposite stresses at points equi-distant from the east-west axis; and (2) each of a pair of sensors mounted at these points on the flexure beams produces an electronic signal equal and opposite to the other, while rejecting the effect of lateral or eccentric loads. Also disclosed are scales incorporating such a load cell.
103 Citations
13 Claims
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1. A low-profile load cell which comprises:
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a. a flat metal plate having a generally uniform horizontal cross-section comprising; (1) a load-receiving member comprising a first transverse section integral with a load-receiving tongue, the load-receiving tongue arranged symmetrically about a north-south axis of the plate, extending across an east-west axis of the plate, and receiving the load to be measured over an area symmetrical about the north-south and east-west axes; (2) a clamping member comprising a second transverse section opposed from the first transverse section across the east-west axis, the clamping member further comprising a pair of clamping tongues integral with the second transverse member and extending across the east-west axis, each camping tongue being symmetrical to the other with respect to the north-south axis; and (3) two flexure beams extending across the east-west axis and connecting the first and second transverse sections of the metal plate, a first half of each flexure beam symmetrical to a second half about the east-west axis, and the flexure beams symmetrical to each other about the north-south axis; and b. a pair of strain transducers mounted on each flexure beam with each sensor equi-distant from the east-west axis; wherein, when a load is applied to the load-receiving element the flexure beams each bend into a symmetrical double-cantilever S-shape, and each transducer in each transducer pair produces an electronic signal equal and opposite to the other transducer in the transducer pair. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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Specification