IP Library Granted Patent US 6,997,442
Granted Patent B2
US 6,997,442 · App. 10/813,424 · Granted Feb 14, 2006

Safety sensor for a lift assembly

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Quick Facts
Patent No.
US 6,997,442
App. No.
10/813,424
Granted
Feb 14, 2006
Kind
B2
Abstract

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

Claims (24)

1. A lift assembly for translating at least one of a batten and a load along a vertical path, the lift assembly comprising:

(a) a sensor connected to and movable vertically with the one of the batten and the load;

(b) a hoisting motor for moving the one of the batten and the load along the vertical path; and

(c) a controller connected to the sensor and a hoisting motor for halting movement of the one of the batten and the load along the vertical path in response to a signal from the sensor.

2. The lift assembly of claim 1 , wherein the sensor is a proximity sensor.

3. The lift assembly of claim 1 , wherein the sensor is an infrared sensor.

4. The lift assembly of claim 1 , wherein the sensor is an ultrasound sensor.

5. A lift assembly having a batten and a hoist connected to the batten for translating the batten along a vertical path, the lift assembly comprising:

(a) a sensor connected to and movable with the batten and located to detect an obstacle in the vertical path of the batten; and

(b) a controller connected to the sensor, the controller configured to stop movement of the batten in response to the sensor detecting an obstacle in the vertical path of the batten.

6. A lift assembly for selectively raising and lowering a load, the lift assembly comprising:

(a) a hoist connected to the load for moving the load along a vertical path;

(b) a sensor connected to and movable with the load to provide a signal corresponding to an object in the vertical path; and

(c) a controller connected to the hoist and the sensor to stop the hoist in response to a signal from the sensor.

7. The lift assembly of claim 6 , wherein the load is a batten.

8. The lift assembly of claim 6 , wherein the controller is wirelessly connected to the sensor.

9. A lift assembly for translating at least one of a batten and a load, comprising:

(a) a sensor fixed to and movable with the at least one of the batten and the load to detect an obstacle in the path of the at least one of the batten and the load; and

(b) a controller for receiving a signal from the sensor and stopping translation of the at least one of the batten and the load.

10. A method of controlling a lift assembly for translating a load along a vertical path, the method comprising:

(a) locating a sensor relative to the load to detect an obstacle in the path of the load, the sensor traveling along a vertical path with the load;

(b) transmitting a signal from the sensor to a controller in response to detecting the obstacle; and

(c) halting movement of the load in response to the transmitted signal.

11. The method of claim 10 , further comprising employing a batten as the load.

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: 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 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 26, 2007
From: HOFFEND, DONALD A., JR
To: HOFFEND & SONS, INC.
Reel/Frame 018811/0030 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 7, 2006
From: HOFFEND & SONS, INC.
To: DAKTRONICS HOIST, INC.
Reel/Frame 018590/0995 →
Continuity (4)
Division 1069013200 · Oct 21, 2003
Division 1027328500 · Oct 17, 2002
Division 0962753700 · Jul 28, 2000
Related Publication 20040183060A1 · Sep 23, 2004