Safety sensor for a lift assembly

• US 6,997,442 B2
• Filed: 03/29/2004
• Issued: 02/14/2006
• Est. Priority Date: 07/28/2000
• Status: Expired due to Term

• Current Assignee: Electronic Theatre Controls Incorporated
• Original Assignee: Hoffend & Sons Inc. (Daktronics Incorporated)
• Inventors: Hoffend, Donald A. Jr.
• Primary Examiner(s): MARCELO, EMMANUEL MONSAYAC
• Application Number:
  US10/813,424
• Publication Number:
  US 20040183060A1
• Time in Patent Office: 687 Days
• Field of Search: 242/267, 242/269, 242/270
• US Class Current: 254/267
• CPC Class Codes: A63J 1/028 Means for moving hanging scenery
• CPC Class Codes: B66D 1/00 Rope, cable, or chain winding mechanisms; Capstans portable or mobile lifting or hauling appliances B66D3/00
• CPC Class Codes: B66D 1/39 by means of axially-movable drums or barrels pivotably mounted drums or barrel B66D1/365
• CPC Class Codes: B66D 5/22 with axial effect

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

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.