IP Library Granted Patent US 7,854,423
Granted Patent B2
US 7,854,423 · App. 12/189,002 · Granted Dec 21, 2010

Modular lift assembly

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Quick Facts
Patent No.
US 7,854,423
App. No.
12/189,002
Granted
Dec 21, 2010
Kind
B2
Abstract

A lift assembly having a drum rotatably mounted to a frame and linearly translatable with respect to one or more portions of the frame. A plurality of head blocks can be connected to the frame along a helical mounting path, wherein linear translation of the drum during takeoff or take-up can maintain a predetermined fleet angle between a take off point from the drum and the head block.

Claims (35)

1. A lift assembly, comprising:

a frame connectable to and supportable by one or more spaced overhead beams;

a drive shaft rotatably connected to the frame about a horizontal axis of rotation;

a drum connected to the drive shaft, the drum including one or more winding sections for reeling one or more cables connectable to a load;

one or more head blocks connected to the frame, each head block configured to turn a cable reeled from the one of the one or more winding sections of the drum; and

a load brake mechanically coupled to a portion of the drum or the drive shaft.

2. The lift assembly of claim 1 , wherein each head block is positioned so as to guide the cable along a cable path in the same direction as the axis of rotation of the drive shaft.

3. The lift assembly of claim 1 , wherein the drum is translatable relative to the frame along the axis of rotation.

4. The lift assembly of claim 3 , wherein translation of the drum maintains a fleet angle between the drum and each head block during raising or lowering of the load.

5. The lift assembly of claim 1 , further comprising at least one loft block for engaging the cable.

6. The lift assembly of claim 1 , further comprising a loft block spaced from the head block, the head block and the loft block defining a cable path passing from the drum to the head block and then horizontally to the loft block.

7. The lift assembly of claim 1 , wherein the load brake includes a drive disc connected to a motor for rotation with the motor, a driven disc connected to the drum for rotation with the drum, and a friction disc located intermediate the drive disc and the driven disc, wherein the drive disc and the driven disc are configured to urge the drive disc and the driven disc against the friction disc in the winding direction of the drum.

8. The lift assembly of claim 1 , further comprising a motor connected to the frame, a gearbox connected to the motor, and wherein the load brake is located between the gearbox and the drum.

9. The lift assembly of claim 1 , further comprising the one or more cables connectable to the load.

10. A lift assembly, comprising:

a frame connectable to and supportable by one or more spaced beams;

a drum rotatably connected to the frame, via a drive shaft, about an axis of rotation, the drum including one or more winding sections for reeling one or more cables connectable to a load;

one or more head blocks connected to the frame, wherein each head block is located to redirect cables extending from the drum along a cable path in the same direction as the axis of rotation of the drum; and

a load brake mechanically coupled to a portion of the drum or the drive shaft.

11. The lift assembly of claim 10 , wherein the drum is translatable relative to the frame along the axis of rotation.

12. The lift assembly of claim 10 , further comprising at least one loft block for engaging the cable.

13. The lift assembly of claim 10 , further comprising a loft block spaced from the head block, the head block and the loft block further defining the cable path passing from the drum to the head block and then to the loft block.

14. The lift assembly of claim 10 , wherein the load brake includes a drive disc connected to a motor for rotation with the motor, a driven disc connected to the drum for rotation with the drum, and a friction disc located intermediate the drive disc and the driven disc, wherein the drive disc and the driven disc are configured to urge the drive disc and the driven disc against the friction disc in the winding direction of the drum.

15. The lift assembly of claim 10 , further comprising a motor connected to the frame, a gearbox connected to the motor, and wherein the load brake is located between the gearbox and the drum.

16. The lift assembly of claim 10 , further comprising the one or more cables connectable to the load.

17. A lift assembly, comprising:

a frame connectable to and supportable by one or more spaced beams;

one or more cables;

a drum rotatably connected to the frame, via a drive shaft, about an axis of rotation, the drum including one or more winding sections for reeling the one or more cables connectable to a load;

one or more head blocks connected to the frame, each head block being fixed relative to the frame for turning one of the one or more cables reeled from the one of the one or more winding sections of the drum;

a loft block spaced from the head block, the head block and the loft block defining a cable path passing from the drum to the head block and then to the loft block, the portion of the cable path between the head block and the loft block being in same direction as the axis of rotation of the drum; and

a load brake mechanically coupled to a portion of the drum or the drive shaft.

18. The lift assembly of claim 17 , wherein the drum is translatable relative to the frame along the axis of rotation.

19. The lift assembly of claim 17 , wherein the load brake includes a drive disc connected to a motor for rotation with the motor, a driven disc connected to the drum for rotation with the drum, and a friction disc located intermediate the drive disc and the driven disc, wherein the drive disc and the driven disc are configured to urge the drive disc and the driven disc against the friction disc in the winding direction of the drum.

20. The lift assembly of claim 17 , further comprising a motor connected to the frame, a gearbox connected to the motor, and wherein the load brake is located between the gearbox and the drum.

Assignments (5)
SECURITY INTEREST Recorded Dec 30, 2015
From: ELECTRONIC THEATRE CONTROLS, INC.
To: JPMORGAN CHASE BANK, N.A.
Reel/Frame 037405/0710 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 28, 2014
From: HOFFEND, DONALD A., JR.
To: HOFFEND & SONS, INC.
Reel/Frame 034053/0748 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 28, 2014
From: HOFFEND & SONS, INC.
To: DAKTRONICS HOIST, INC.
Reel/Frame 034054/0024 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 28, 2014
From: DAKTRONICS, INC.
To: ELECTRONIC THEATRE CONTROLS, INC.
Reel/Frame 034054/0350 →
DISSOLUTION OF WHOLLY - OWNED SUBSIDIARY Recorded Jul 31, 2014
From: DAKTRONICS HOIST, INC.
To: DAKTRONICS, INC.
Reel/Frame 033453/0503 →