Apparatus, system and method for weighing loads in motion

• US 20080073129A1
• Filed: 09/21/2006
• Published: 03/27/2008
• Est. Priority Date: 09/21/2006
• Status: Active Grant

• Current Assignee: Technical Weighing Services, Inc.
• Original Assignee: Technical Weighing Services, Inc.
• Inventors: Heuer, David M.
• Granted Patent: US 7,514,639 B2
• Time in Patent Office: Days
• US Class Current: 177/136
• CPC Class Codes: B66C 13/16 Applications of indicating, registering, or weighing devices in crane hooks B66C1/40; in safety gear B66C15/00; weighing-apparatus G01G; remote indicating in general G08
• CPC Class Codes: G01G 19/18 having electrical weight-sensitive devices
• CPC Class Codes: G01G 23/3728 with wireless means

Abstract

The apparatus for weighing a load in motion includes a rigid member, a plurality of strain gages mounted within the rigid member and forming a Wheatstone bridge network for measuring a force exerted by such load onto the rigid member and an accelerometer mounted within the rigid member for measuring gravitational acceleration of the load. A controller mounted in remote location compensates the measured force according to a measurement from the accelerometer and according to a predetermined algorithm to determine the actual weight of the load. Strain gages and accelerometer are connected to the controller by way of a wiring connection. The apparatus can be easily retrofitted into existing applications, particularly for loading scrap metal by way of a crane.

Claims

1. An apparatus for weighing a load in motion, said apparatus comprising:

(a) a rigid member having an upper end, a vertically opposed lower end which is oriented toward such load and is axially aligned with said upper end, a first vertical surface portion joining said upper end and said lower end and an opposed second vertical surface portion joining said upper end and said lower end;

(b) a first measuring means attached to said rigid member in a vertical and axial alignment with such load for measuring a force exerted by such load onto said rigid member and for generating at least one force measurement signal, said at least one force measurement signal characterizing said measured force;

(c) a second measuring means attached to said rigid member for measuring a predetermined parameter associated with a motion of such load and for generating at least one motion parameter measurement signal, said at least one motion parameter measurement signal characterizing said measured motion parameter; and

(d) means coupled to each of said first measuring means and said second measuring means for transmitting said at least one force measurement signal and said at least one motion parameter measurement signal to a control means capable of executing a predetermined logic algorithm.

2. The apparatus, according to claim 1, wherein said first measuring means includes:

(a) a first pair of opposed cavities each formed in a respective one of said first surface portion and said second surface portion of said rigid member and disposed at a predetermined distance from a vertical axis of said rigid member, said first pair of opposed cavities forming a first vertically oriented wall portion capable of deforming under said force applied by such load onto said rigid member;

(b) a second pair of opposed cavities each formed in said respective one of said first surface portion and said second surface portion of said rigid member and disposed at said predetermined distance from said vertical axis of said rigid member and opposing said first pair of opposed cavities, said second pair of opposed cavities forming a second vertically oriented wall portion capable of deforming under said force applied by such load onto said rigid member, said second pair of opposed cavities is horizontally aligned with said first pair of opposed cavities;

(c) a first pair of strain gages, each securely fixed to a respective surface of said first vertically oriented wall portion;

(d) a second pair of strain gages, each securely fixed to a respective surface of said second vertically oriented wall portion; and

(e) said first pair of strain gages and said second pair of strain gages being connected in series to form a Wheatstone bridge network.

3. The apparatus, according to claim 1, wherein said second measuring means is an accelerometer and wherein said motion parameter is a gravitational acceleration of such load.

4. The apparatus, according to claim 3, wherein said accelerometer is mounted to a vertical wall of a cavity formed in said rigid member to measure said gravitational acceleration in a vertical plane.

5. The apparatus, according to claim 4, wherein said apparatus includes means disposed intermediate said accelerometer and said vertical wall of said cavity formed in said rigid member for absorbing detrimental shock and vibration forces present in an operating environment of said apparatus.

6. The apparatus, according to claim 1, wherein said signal transmitting means includes at least one of a wired and wireless connection means.

7. The apparatus, according to claim 1, wherein said apparatus further includes said control means capable of executing said predetermined logic algorithm.

8. The apparatus, according to claim 7, wherein said control means is mounted in a remote location.

9. In combination with a load handling apparatus having a load moving portion and a load carrying device and capable of at least one of lifting and horizontally moving a load, the improvement comprising an apparatus for weighing such load in motion, said apparatus including:

(a) a rigid member having an upper end, a vertically opposed lower end which is oriented toward such load and axially aligned with said upper end, a first vertical surface portion joining said upper end and said lower end and an opposed second vertical surface portion;

(b) a first measuring means attached to said rigid member in a vertical and axial alignment with such load for measuring a force exerted by such load onto said rigid member and for generating at least one force measurement signal, said at least one force measurement signal characterizing said measured force;

(c) a second measuring means attached to said rigid member for measuring a predetermined parameter associated with a motion of such load and for generating at least one motion parameter measurement signal, said at least one motion parameter measurement signal characterizing said measured movement parameter;

(d) means coupled to each of said first measuring means and said second measuring means for transmitting said at least one force measurement signal and said at least one motion parameter measurement signal to a control means capable of executing a predetermined logic algorithm;

(e) a first attachment means for attaching said upper end of said rigid member to such load moving portion in a substantially semi-permanent fashion; and

(f) a second attachment means for attaching said lower end of said rigid member to such load carrying device in a substantially semi-permanent fashion.

10. The combination, according to claim 9, wherein said load handling apparatus is a crane having a load arm and wherein said first attachment means includes:

(a) a bifurcated portion formed in said upper end;

(b) a pair of apertures formed within said bifurcated portion and disposed about a common horizontal axis;

(c) an elongated link having a first aperture formed adjacent a first end and a second aperture formed adjacent an opposed second end of said link, wherein longitudinal axis of each of said first aperture and said second aperture are disposed in a horizontal plane and are perpendicular to each other;

(d) a first shaft member passed through a combination of said first aperture formed in said link and a complimentary aperture formed in such distal end of such load arm for pivotally connecting said link to such load arm; and

(e) a second shaft member passed trough said pair of apertures of said bifurcated end and said second aperture formed in said link and aligned with said pair of apertures formed within said bifurcated portion for pivotally connecting said link to said rigid member, whereby a pivotal connection of said link to such load arm in combination with a pivotal connection of said bifurcated upper end to said link enable a rotational freedom of said rigid member about such load arm.

11. The combination, according to claim 9, wherein said second attachment means includes:

(a) an aperture formed within said lower end of said rigid member; and

(b) a shaft member passed through said aperture and through a pair of apertures formed within a bifurcated end of such load carrying device for pivotally connecting said rigid member thereto.

12. The combination, according to claim 9, wherein such load carrying device is one of magnet, hook, claw, jaw, bucket and various combinations thereof.

13. In combination with a load handling apparatus having a load moving portion and a load carrying device and capable of at least one of lifting and horizontally moving a load, the improvement comprising a system for weighing such load in motion, said system including:

(a) a control means capable of executing a predetermined logic algorithm;

(b) a first measuring means attached to such load carrying device and coupled to said control means for measuring a force exerted by such load onto such load carrying device and for providing at least one force measurement signal to said control means, said at least one force measurement signal characterizing said measured force;

(c) a second measuring means attached to such load carrying device and coupled to said control means for measuring a predetermined parameter associated with a motion of such load and for providing at least one parameter measurement signal to said control means, said at least one motion parameter measurement signal characterizing said measured movement parameter;

(d) means for coupling said first measuring means and said second measuring means to said control means; and

(e) whereby said control means which is mounted remotely from said first measuring means and said second measuring means compensates said measured force in accordance with said measured motion parameter and in accordance with said predetermined logic algorithm for determining an actual mass of such load as it being moved by such load handling apparatus.

14. In combination with a load handling apparatus having a load moving portion, a load carrying device and a load sensor coupled therebetween, said load sensor having a housing and at least a force measuring member and a motion compensating member mounted within said housing, the improvement comprising means mounted between said motion compensating member and a predetermined portion of said housing for absorbing detrimental shock and vibration forces present in an operating environment of said load handling apparatus.

15. In combination with a load handling apparatus having a load moving portion, a load carrying device and a load sensor coupled therebetween, said load sensor having at least a force measuring member, a motion compensating member and a control means coupled to said force measuring member and to said motion compensating member and capable of executing a predetermined logic algorithm wherein a measurement from such force measuring member is compensated by a measurement from such motion compensating member to determine an actual weight of such load during motion, the improvement comprising a step of defining by such control means within such predetermined logic algorithm a steady state condition during motion of such load prior to determining such actual weight of such load.

16. A method of dynamically weighing a load in motion, said method comprising the steps of:

(a) measuring a force exerted by said load onto said load moving apparatus;

(b) providing at least one force measurement signal which characterizes said measured force to a control means capable of executing a predetermined logic algorithm;

(c) measuring a parameter associated with said motion of said load;

(d) providing at least one motion parameter measurement signal which characterizes said measured motion parameter to said control means;

(e) defining, by said control means, a steady state condition during said motion of said load; and

(f) determining a mass of said load during said steady state condition.

17. The method, according to claim 16, wherein said steady state condition is defined in step (e) by incrementally calculating a change of said measured mass over time and determining when said change is within a predetermined threshold.

18. The method, according to claim 16, wherein said method further includes the step of compensating for a predetermined mass of a load carrying device when measuring said mass of said load in step (f).

19. The method, according to claim 16, wherein said method further includes the step of saving said mass measured in step (f) to a database.

20. In combination with a load carrying device having a rigid upper body for attachment to a load handling apparatus and a load carrying portion coupled to such rigid upper body, the improvement comprising:

(a) a first measuring means mounted within a first predetermined portion of such rigid upper body and in a vertical and axial alignment with such load for measuring a force exerted by such load onto said lifting device and for generating at least one force measurement signal, said at least one force measurement signal characterizing said measured force; and

(b) a second measuring means mounted within a second predetermined portion of such rigid upper body for measuring a predetermined parameter associated with a motion of such load and for generating at least one parameter measurement signal, said at least one motion parameter measurement signal characterizing said measured motion parameter; and

(c) means coupled to each of said first measuring means and said second measuring means for transmitting said at least one force measurement signal and said at least one motion parameter measurement signal to a control means capable of executing a predetermined logic algorithm.