Gaged plate transducer weighing apparatus

• US 4,506,746 A
• Filed: 09/27/1982
• Issued: 03/26/1985
• Est. Priority Date: 09/27/1982
• Status: Expired due to Term

• Current Assignee: Hottinger Baldwin Measurements, Inc. (Spectris PLC)
• Original Assignee: Hottinger Baldwin Measurements, Inc. (Spectris PLC)
• Inventors: Lockery, Harry E.
• Primary Examiner(s): MILLER JR, GEORGE
• Application Number:
  US06/424,485
• Time in Patent Office: 911 Days
• Field of Search: 177/211, 177/229
• US Class Current: 177/211
• CPC Class Codes: G01G 3/12 wherein the weighing element is in the form of a solid body stressed by pressure or tension during weighing
• CPC Class Codes: G01G 3/1402 Special supports with preselected places to mount the resistance strain gauges; Mounting of supports

Abstract

A platform for a scale is formed by elongate elements rigidly interconnected to provide a platform frame structure having, for example, an H-configuration. The strain gage transducer beams are formed integrally at each end of the elongate elements. Vertical load components are introduced into the transducer beams by suitably locating support feet under the platform frame structure so that the beams may properly flex. Load transfer from an upper platform to the transducer beams is preferably accomplished by ball and socket loading devices provided at each end of the elongate elements forming the frame structure.

Claims

1. A strain gage weighing apparatus having upper and lower horizontal members arranged in substantially parallel planes relative to each other, said upper horizontal member comprising platform means for receiving a load to be weighed, said lower horizontal member comprising strain gage transducer beam means for measuring the weight of a load, load transfer means operatively arranged between said upper and lower horizontal members for transmitting vertical force components from the upper horizontal member to the strain gage transducer beam means while substantially preventing the transmission of horizontal force components between said upper and lower horizontal members, and foot means for stabilizing the weighing apparatus, said lower horizontal member comprising at least two elongate elements joined to form said lower horizontal member as a rigid frame structure, said strain gage transducer beam means being constructed as integral parts of said two elongate elements adjacent the ends thereof;

said foot means being operatively arranged relative to the ends of said two elongate elements for applying a load representing force to each of the respective integral strain gage transducer beam means through said transfer means from the upper horizontal member to said strain gage transducer beam means, wherein said integral strain gage transducer beam means are spaced from the end of the respective elongate element, each of said transducer beam means having a root end merging into the respective elongate element in the direction of the center of said elongate element and a free end extending in the direction toward the outer end of said elongate element for flexural movement of the integral strain gage transducer beam means relative to said elongate element, said free end of the transducer beam means being spaced from the respective end of the respective elongate element (55) for defining a non-flexural frame element area (56) between the free flexural end (52) of the transducer beam means (50) and the end (54) of said elongate element (55), whereby said transducer beam means (50) is surrounded along all edges thereof by the respective elongate element (55), securing means for securing said foot means to said non-flexural frame element area (56) at the end of said elongate elements (55) outside of the respective transducer beam means (50), and wherein said load transfer means include a bracket between said upper member and the free flexural end (52) of the respective transducer beam means (50) for deforming the latter.

2. The weighing apparatus of claim 1, wherein said lower horizontal member comprises first and second elongate elements arranged in a common plane in a substantially parallel spaced apart configuration, said lower horizontal member further comprising at least a third elongate connector element integrally joining said first and second elongate elements to form said rigid frame structure (FIGS. 2 or 3).

3. The weighing apparatus of claim 1, wherein said lower horizontal member comprises first and second elongate elements arranged in a cross-over configuration, and means rigidly joining said first and second elongate elements at a cross-over area, (FIGS. 4, 4A, 4B).

4. The weighing apparatus of claim 1, wherein each of said integral transducer beam means is formed in the elongate elements by three slots, two of which are arranged in parallel to each other and a third slot interconnecting the parallel slots at one end thereof for defining the free end of the transducer beam means, and wherein holes are drilled into said elongate element along the slots at said free end, at said root end, and intermediate the free end and root end thereby providing a total of six holes, (FIG. 5).

5. The weighing apparatus of claim 1, wherein said securing means for said foot means comprise a threaded means with a threaded hole at each end, and an adjustment screw carrying said foot means at one end thereof and reaching with the other end thereof into one threaded hole of said threaded means, said adjustment screw being adjustable for leveling the weighing apparatus, said apparatus further comprising an adjustable set screw in the other threaded hole of the same threaded means for providing an overload stop, said threaded holes of said threaded means being in axial alignment with each other for introducing an overload directly into said foot means.

11. The weighing apparatus of claim 1 or 10, wherein said load transfer means comprise ball and socket elements operatively interposed between a load and said integrally constructed transducer beam means.

6. In a strain gage weighing apparatus including platform means, transducer beam means constructed as an integral part of said platform means, said transducer beam means having a flexural free end and a fixed root end merging into said platform means, strain gage sensor means operatively secured to said transducer beam means, and foot means operatively secured for permitting action on the free end of the respective beam transducer means, the improvement comprising at least two elongate elements arranged substantially in a common plane, means rigidly joining said elongate elements to form said platform means, wherein said strain gage sensor means carrying transducer beam means are integrally formed in said two elongate elements adjacent the ends thereof, and wherein said transducer beam means formed at each end of the two elongate elements are located inside the perimeter of the elongate elements, each side, except the flat sides, of each transducer beam means thereby being wholly enclosed by the respective elongate element.

7. The weighing apparatus of claim 6, wherein said platform means comprises first and second elongate elements arranged in a parallel spaced apart configuration and further comprising at least a third connecting elongate element integrally joining said first and second elongate elements to form a rigid structure.

8. The weighing apparatus of claim 6, wherein each of said transducer beam means comprises two slots formed in the elongate element adjacent the respective ends thereof, said two slots being arranged in a parallel configuration and a third slot interconnecting said two slots for defining said free end, each of said transducer beam means being further formed by holes drilled through said elongate elements at the free end, at the root end, and intermediate said free end and said root end.

9. The weighing apparatus of claim 8, wherein said third slot is located near the outer end of the elongate element so that said free end of said transducer beam means is oriented in the direction of the outer end of the elongate element, said root end being oriented in the direction toward the center of the respective elongate element.

10. The weighing apparatus of claim 6, said apparatus further comprising load transfer means for said beam means arranged for being operatively effective on said flexural free end of the beam transducer means through said load transfer means.

12. A strain gage weighing apparatus having upper and lower horizontal members arranged in substantially parallel planes relative to each other, said upper horizontal member comprising platform means for receiving a load to be weighed, said lower horizontal member comprising strain gage transducer beam means for measuring the weight of a load, load transfer means operatively arranged between said upper and lower horizontal members for transmitting vertical force components from the upper horizontal member to the strain gage transducer beam means while substantially preventing the transmission of horizontal force components between said upper and lower horizontal members, and foot means for stabilizing the weighing apparatus, said lower horizontal member comprising at least two elongate elements joined to form said lower horizontal member as a rigid frame structure, said strain gage transducer beam means being constructed as integral parts of said two elongate elements adjacent the ends thereof;

said foot means being operatively arranged relative to the ends of said two elongate elements for applying a load representing force to each of the respective integral strain gage transducer beam means through said transfer means from the upper horizontal member to said strain gage transducer beam means, each of said strain gage transducer beam means comprising two strain gage elements operatively secured to the respective transducer beam means with a spacing between said two strain gage elements, and wherein each of said foot means comprises a bridging member (75), two spacers (75'"'"'), means (76) securing said bridging member (75) and said spacers (75'"'"') to the bottom side of the respective elongate element centrally across said spacing between the respective two strain gage elements for bridging the respective transducer beam means on the bottom side of said respective elongate element, said foot means comprising a ground engaging foot (74) secured to the bottom of the respective bridging member and in the center thereof, said load transfer means (63) being arranged centrally above said spacing, whereby said foot is located in vertical register with the respective one of said load transfer means and thus vertically under the point of load application.

13. The apparatus of claim 12, further comprising overload stop means (82) arranged for cooperation with a surface of said elongate element (72) opposite said bridging member.

14. The weighing apparatus of claim 12, wherein each of said transducer beam means is formed in the respective ends of the two elongate elements by slots cut to run in parallel to longitudinal sides of the respective elongate element, each of said transducer beam means further comprising holes drilled into said panel means substantially at the ends of said slots and intermediate the ends of said slots, (FIG. 6).