DUMP TRUCK LOAD-SENSING ASSEMBLY

• US 3,857,452 A
• Filed: 02/14/1974
• Issued: 12/31/1974
• Est. Priority Date: 02/14/1974
• Status: Expired due to Term

• Current Assignee: James M. Hartman
• Original Assignee: James M. Hartman
• Inventors: Hartman, James M.
• Primary Examiner(s): Miller, Jr., George H.
• Application Number:
  US05/442,375
• Time in Patent Office: 320 Days
• Field of Search: 177/136,139,211 73/141A
• US Class Current: 177/139
• CPC Class Codes: G01G 19/12 having electrical weight-sensitive devices
• CPC Class Codes: G01G 3/1404 combined with means to connect the strain gauges on electrical bridges
• CPC Class Codes: G01L 1/2225 the direction being perpendicular to the central axis

Abstract

A load-sensing assembly supports and measures the weight of a container pivotally carried on a vehicle. One end of the container is pivotally mounted to one portion of the vehicle frame by hinge pin means. The other end of the container is mounted to one end of at least one extendible means which in turn is pivotally mounted by hinge pin means to another portion of the frame. The hinge pin means are adapted to measure and carry the entire weight of the container. Each hinge pin means has an outer tubular collar which includes a plurality of cylindrical sections adapted to engage and join in pivotal coupling relationship various load transferring and load receiving members. Integral with and enclosed by the collar is an essentially cylindrical load cell which has longitudinally spaced peripheral land surfaces for engagement with the various cylindrical sections of the tubular collar, and peripheral recessed surfaces intermediate the land surfaces for the purpose of concentrating axial moment stresses at the bottom peripheral portions thereof. Strain gauges are secured to the bottom peripheral portions of the recessed surfaces and have electrical leads connected to external measuring instrumentation. By this arrangement and the orientation of the strain gauges, the weight of the container and any material present therein may be measured by evaluation of the axial moment stresses produced in the load cells.

Claims

1. A pin load-sensing apparatus for measuring the load between a load transferring member and load receiving members comprising an essentially cylindrical load cell integral with and surrounded by a tubular collar wherein said tubular collar comprises a plurality of cylindrical sections adapted to engage with and join said load transferring and load receiving members in pivotal coupling relationship, and wherein said essentially cylindrical load cell comprises longitudinally spaced peripheral land surfaces adapted to engage the cylindrical sections of said tubular collar, and peripheral recessed surfaces intermediate said land surfaces and positioned to concentrate axial moment stresses at the bottom peripheral portions of said recessed surfaces when a load is applied to said cell, there being a set of electrical strain gauges operationally bonded directly to the bottom peripheral portion of each of said peripheral recessed surfaces in a manner to enable said gauges to respond to differential axial moment stresses therein resulting from deformation of said load cell due to a loading force being exerted on said load cell by said load transferring member.

2. The apparatus according to claim 1 wherein said tubular collar comprises a central cylinder having radially inwardly beveled edges and adapted to engage said load transferring member, and two end cylinders each having a radially inwardly beveled edge abutting a beveled edge of said central cylinder, each end cylinder being adapted to engage one of said load receiving members, and wherein said load cell comprises three of said land surfaces and two of said peripheral recessed surfaces, said peripheral recessed surfaces being positioned opposite the junction of said tubular collar'"'"''"'"'s abutting beveled edges, the bottom peripheral portion of each of said peripheral recessed surfaces having two electrical strain gauges spaced apart and operationally bonded directly thereto along an axis parallel to the axis of said load cell.

3. The apparatus according to claim 2 wherein said load cell further includes a longitudinal groove extending the length of the intermediate peripheral land surface, an open-ended axial socket disposed within one end of said load cell, a duct connecting said socket with the outer surface of said load cell, a seal fitting covering the axial opening of said socket, said seal fitting having four electrical connection means extending outwardly therefrom, and wires connecting each of said strain gauges to one of said electrical connection means extending from said seal fitting, two of said wires passing through said groove and joining the remaining two wires to pass through said duct into said socket to be connected to said electrical connection means, the end of said load cell opposite the end containing said socket having a notch for attachment to a load receiving member to prevent rotation of said load cell, and wherein said apparatus further includes means for connecting said electrical connection means to the appropriate arms of a bridge circuit, adjustable means for balancing said bridge circuit, means for supplying substantially constant electrical energy to said bridge circuit, and means to meter the response of said strain gauges to a loading force exerted on said load cell by said load transferring member.

4. A load-sensing assembly for supporting and measuring the weight of a container pivotally mounted on a vehicle frame comprising:

a vehicle frame mounted for movement over a ground surface;

a container mounted on said frame with one end of said container having at least one load transferring member suspended therefrom which is pIvotally secured by hinge pin means to load receiving members affixed to one portion of said frame, and the opposite end of said container attached to at least one extendible means having a load transferring member pivotally mounted by hinge pin means to load receiving members affixed to another portion of said frame, said hinge pin means supporting the entire weight of said container and adapted to measure said weight;

hinge pin means comprising an essentially cylindrical load cell surrounded by a tubular collar wherein said tubular collar comprises a plurality of cylindrical sections adapted to engage and join said load transferring and load receiving members in pivotal coupling relationship, and wherein said essentially cylindrical load cell comprises longitudinally spaced peripheral land surfaces adapted to engage the cylindrical sections of said tubular collar, and peripheral recessed surfaces intermediate said land surfaces and positioned to concentrate axial moment stresses at the bottom peripheral portions thereof, there being a set of electrical strain gauges operationally bonded directly to the bottom peripheral portion of each of said peripheral recessed surfaces in a manner to enable said gauges to respond to differential axial moment stresses therein resulting from deformation of said load cell;

means for securing said load cell to prevent rotation thereof; and

means to meter the response of said gauges to a loading force exerted on said load cell by said container.

5. The assembly according to claim 4 wherein one end of said container has two load transferring members suspended therefrom along an axis which is essentially perpendicular to the longitudinal axis of said frame, each of said load transferring members being pivotally secured by said hinge pin means to load receiving members affixed to the rearward portion of said frame, and wherein the opposite end of said container is attached to one end of an extendible rod, the other end of said rod having a load transferring member pivotally mounted by said hinge pin means to load receiving members affixed to the forward central portion of said frame.

6. The assembly according to claim 4 wherein said tubular collar comprises a central cylinder having radially inwardly beveled edges and adapted to engage a load transferring member, and two end cylinders each having a radially inwardly beveled edge abutting a beveled edge of said central cylinder, each end cylinder being adapted to engage a load receiving member, and wherein said peripheral recessed surfaces are positioned radially inward the junctions of said tubular collar'"'"''"'"'s abutting beveled edges.

7. The assembly according to claim 6 wherein said load cell includes three of said land surfaces separated by two of said peripheral recessed surfaces, the bottom peripheral portion of each of said peripheral recessed surfaces having two electrical strain gauges spaced apart and operationally bonded directly thereto along an axis parallel to the axis of said load cell, and wherein said assembly further includes means for connecting said strain gauges in the appropriate arms of a bridge circuit, adjustable means for balancing said bridge circuit when said container is empty, and means for supplying a substantially constant electrical energy to said bridge circuit.

8. The assembly according to claim 7 wherein said load cell further includes a longitudinal groove extending the length of the intermediate peripheral land surface, an open-ended axial socket disposed within one end of said load cell, a duct connecting said socket with the outer surface of said load cell, and wires secured to said strain gauges, the wires from two of said strain gauges passing through said groove and joining the remaining wires to pass through said duct into said socket for connection to said bridge circuit.

9. The assembly according to claim 8 wherein the end of said load cell opposite the end containing said socket includes a slot for attachment to a load receiving Member to prevent rotation of said load cell.

10. A dump truck load-sensing assembly comprising:

a dump truck frame mounted for movement over a ground surface;

an open container mounted on said frame with the rearward end of said container having at least one load transferring member suspended therefrom along an axis essentially perpendicular to the longitudinal axis of said frame, each load transferring member being pivotally secured by hinge pin means to load receiving members affixed to the rearward portion of said frame, and the forward end of said container attached to the extendible end of at least one hydraulic lift rod, the other end of each lift rod having a load transferring member pivotally mounted by hinge pin means to load receiving members affixed to the forward portion of said frame, said hinge pin means supporting the entire weight of said open container and adapted to measure said weight;

hinge pin means comprising an essentially cylindrical load cell integral with and surrounded by a tubular collar wherein said tubular collar comprises a central cylinder having radially inwardly beveled edges and adapted to engage a load transferring member, and two end cylinders each having a radially inwardly beveled edge abutting a beveled edge of said central cylinder, each end cylinder being adapted to engage a load receiving member, said tubular collar joining said load transferring and load receiving members in pivotal coupling relationship, and wherein said essentially cylindrical load cell comprises three longitudinally spaced peripheral land surfaces adapted to engage the central and end cylinders of said tubular collar, and two peripheral recessed surfaces intermediate said land surfaces and positioned radially inwardly the junctions of said tubular collar'"'"''"'"'s abutting beveled edges so as to concentrate axial moment stresses at the bottom peripheral portions of said recessed surfaces, there being two electrical strain gauges spaced apart and operationally bonded directly to the bottom peripheral portion of each of said peripheral recessed surfaces along an axis parallel to the axis of said load cell in a manner to enable said gauges to respond to differential axial moment stresses therein resulting from deformation of said load cell;

means for securing said load cell to prevent rotation thereof;

means for connecting said gauges in the appropriate arms of a bridge circuit;

adjustable means for balancing said bridge circuit when said container is empty;

means for supplying a substantially constant electrical energy to said bridge circuit; and

means to meter the response to said bridge circuit to determine the response of said gauges to a loading force exerted on said load cell by said container.

11. The assembly according to claim 10 wherein said load cell further includes a longitudinal groove extending the length of the intermediate peripheral land surface, an open-ended axial socket disposed within one end of said load cell, a duct connecting said socket with the outer surface of said load cell, a seal fitting covering the axial opening of said socket, said seal fitting having four electrical connection means extending outwardly therefrom, and wires connecting each of said strain gauges to one of the electrical connection means extending from said seal fitting, two of said wires passing through said groove and joining the remaining two wires to pass through said duct into said socket to be connected to said electrical connection means, and wherein the end of said load cell opposite the end containing said socket includes a slot for attachment to a load receiving member to prevent rotation of said load cell.