DYNAMIC SCALE FOR BULK MATERIAL

• US 20100126781A1
• Filed: 04/25/2008
• Published: 05/27/2010
• Est. Priority Date: 04/26/2007
• Status: Active Grant

• Current Assignee: DIGI SENS Holding AG
• Original Assignee: Digi Sens AG
• Inventors: Lustenberger, Martin
• Granted Patent: US 8,507,810 B2
• Time in Patent Office: Days
• US Class Current: 177/136
• CPC Class Codes: B65F 2003/022 the discharging means comprising a device for determining the weight of the content of refuse receptacles
• CPC Class Codes: B65F 2003/0279 the discharging means mounted at the front of the vehicle
• CPC Class Codes: G01G 19/083 lift truck scale

Abstract

The invention relates to a dynamic scale for bulk material, having two swivel arms (2) and two load-lifting arms (8) mounted to the free end of said swivel arms, with one hole (7) being located in each of the swivel arms (2) and positioned transversely to the extension of the swivel arm and also transversely to the neutral fiber brought about by the flexural load. A pipe (9) is fitted into the hole (7) and is welded thereto. The pipe (9) comprises two sensors (14, 15) transversely to the longitudinal axis thereof, said sensors being located at an angle of substantially 90° to each other and each being disposed at an angle of ±45° to the direction of the shear stress component τ_xy. Under the influence of the shear stress, the cross section of the tube (9) is deformed into an ellipse that is inclined at about 45°, the shorter and longer axis (11, 13) thereof being measured using the sensors (14, 15). Said sensors (14, 15) each comprise two force inlets (16, 17), which are inserted with pretension in suitable recesses in the tube (9).

Claims

1. Dynamic scale for bulk material having two swivel arms (2), which can be moved individually or in unison, two hydraulic cylinders (3) and at least one load holding arm (8) per swivel arm (2),

characterised in that

means are available in each swivel arm (2) to measure the shear stress in said swivel arm,

each independently movable swivel arm (2) carries an acceleration sensor (6), with which the determination of mass can be corrected by the current acceleration value.

2. Dynamic scale for bulk material according to claim 1,

characterised in that

the means for measuring the shear stress in the swivel arm (2) consist of

a pipe (9), which is inserted into a hole (7) transversely to the neutral fibre of the bending strain of the swivel arm (2) and is welded into said hole (7),

at least one sensor (14, 15), which is fitted transversely to the longitudinal axis of the pipe (9) in said pipe and can measure the changes in the diameter of the pipe (9) under the influence of the shear stress,

this at least one sensor (14, 15) is inserted essentially at an angle of ±

45°

to the direction of the shear stress t_xy of the swivel arm (2).

3. Dynamic scale for bulk material according to claim 2,

characterised in that

two sensors (14, 15) are inserted in the pipe (9) and are arranged at a mutual angle of essentially 90°

to each other, wherein the one sensor (14) measures the enlargement of the diameter of the pipe (19), the other sensor (15) its contraction.

4. Dynamic scale for bulk material according to claim 2 or 3,

characterised in that

the sensors (14, 15) have two force inputs (16, 17) each,

for each force input (16, 17) the pipe (9) has a suitable recess, in which the force inputs are inserted under pre-tension.

5. Dynamic scale for bulk material according to claim 2 or 3,

characterised in that

the sensors (14, 15) have two force inputs (16, 17) each,

for every force input (16, 17) a bracket is welded in the pipe (9), on which the force input (16, 17) is secured by means of a screw connection.

6. Dynamic scale for bulk material according to claims 2 and 4,

characterised in that

a weighing window is defined by the measurements of the acceleration sensor (6), within which the acceleration values do not exceed a given limit.

7. Dynamic scale for bulk material according to claims 2 and 4,

characterised in that

a weighing window is defined by the traversal of the lifting arms (2) past at least one contactless switch.

8. Dynamic scale for bulk material according to claim 6 or 7,

characterised in that

during the tipping process, the gross weight is measured while the swivel arms (2) are raised, and the tare weight while the swivel arms (2) are lowered, while said arms are in motion.

9. Dynamic scale for bulk material according to claim 6 or 7,

characterised in that

the determination of the load of the full or empty refuse container (5) is made during the traversal of the weighing window.

10. Dynamic scale for bulk material according to claim 2,

characterised in that

the tipping device is constructed as a front-loading or side-loading or rear-loading device.