System for Reducing Injury from Pinch Zones in Adjustable Height Work Surface Assemblies

• US 20190098994A1
• Filed: 10/01/2018
• Published: 04/04/2019
• Est. Priority Date: 10/02/2017
• Status: Active Grant

• Current Assignee: Ole Smed
• Original Assignee: Ole Smed
• Inventors: Smed, Ole Falk
• Granted Patent: US 10,617,201 B2
• Time in Patent Office: Days
• CPC Class Codes: A47B 21/02 with vertical adjustable parts
• CPC Class Codes: A47B 2200/0056 with a motor, e.g. an electric motor
• CPC Class Codes: A47B 2200/0062 Electronically user-adaptable, height-adjustable desk or table
• CPC Class Codes: A47B 9/00 Tables with tops of variable height lecterns with variable height A47B19/06; school forms or desks with variable height A47B39/02, A47B41/02; seats with variable height A47C3/20
• CPC Class Codes: G05B 19/0428 Safety, monitoring G05B19/0423 takes precedence
• CPC Class Codes: G05B 19/416 characterised by control of velocity, acceleration or deceleration G05B19/19 takes precedence
• CPC Class Codes: G05B 2219/50378 Control height gripper as function of thickness of workpiece and height of pallet

Abstract

Embodiments of a system for reducing injury from pinch zones in adjustable-height work surface assemblies are shown, the system including a desk surface; one or more adjustable-height legs, a controller for the adjustable-height legs; a Hall-effect sensor providing a signal to the system corresponding to a current draw of a motor in the adjustable height leg and wherein the system disables the motor if the current draw of the motor exceeds a fixed set point; and a proximity detection sensor being a strip of conducting material disposed adjacent to a perimeter of the desk surface and in electrical connection with an LC tank circuit, wherein the LC tank circuit is configured to exhibit a change in state when an object is in close proximity to the strip of conducting material and wherein the system disables the motor when the LC tank circuit exhibits the change in state.

Claims

1. An assembly comprising:

a desk surface;

at least one adjustable-height leg, said adjustable height leg having an outer shell, a top casting for engagement with the desk surface and an actuator with a motor disposed within the outer shell for adjusting the height of the leg;

a controller for the at least one adjustable-height leg, said controller having an adjustment switch for receiving a user input to raise or lower the adjustable-height leg, said controller further having a system for preventing pinch injuries during the operation of the adjustable height leg, said system comprising;

a Hall-effect sensor in electrical connection with an electrical input terminal of the motor, said Hall-effect sensor providing a signal to the system corresponding to a current draw of the motor and wherein the system is configured to disable the motor if the current draw of the motor exceeds a fixed set point; and

a proximity detection sensor connected to the system, wherein said proximity detection sensor is a strip of conducting material disposed adjacent to a perimeter of the desk surface and in electrical connection with an LC tank circuit, wherein said LC tank circuit is configured to exhibit a change in state when an object is in close proximity to the strip of conducting material and wherein the system is configured to disable the motor when the LC tank circuit exhibits the change in state.

2. The assembly of claim 1, wherein the system for preventing pinch injuries is powered by electrical power from the controller.

3. The assembly of claim 1, wherein the at least one adjustable-height leg is provided with a foot casting and is free-standing.

4. The assembly of claim 1, wherein three adjustable-height legs are included in the assembly.

5. The assembly of claim 1, wherein the change in state of the LC tank circuit is a change in capacitance.

6. The assembly of claim 1, wherein the change in state of the LC tank circuit is a change in frequency.

7. The assembly of claim 1, the LC tank circuit'"'"'s frequency changes when the proximity detection sensor is disconnected and the controller disables the motor in response to this frequency change.

8. The assembly of claim 1, wherein the proximity detection sensor is formed from a material selected from the group comprising aluminum sheets, copper tape, solid copper wire, braided copper wire, aluminum tape and plastic sheets coated with indium tin oxide.

9. The assembly of claim 1, wherein the system further comprises a visual indicator that alerts the user that a collision or a proximity detection event has occurred or may imminently occur.

10. The assembly of claim 1, wherein the system further comprises a audio indicator that alerts the user that a collision or a proximity detection event has occurred or may imminently occur.

11. The assembly of claim 1, wherein the proximity detection sensor has a long, narrow body with a connector disposed at one end thereof.

12. The assembly of claim 11, wherein the proximity detection sensor is 800 mm long and 12 mm wide.

13. The assembly of claim 1, wherein the proximity detection sensor is comprised of layers including an FR4 substrate, a conducting layer and a solder resist layer.

14. The assembly of claim 13, wherein the conducting layer is selected from the group comprising copper, aluminum and gold.

15. The assembly of claim 13, wherein a connector is electrically connected by solder to the conducting layer in the proximity detection sensor.

16. The assembly of claim 15, wherein a wire electrically connects the connector to the system for preventing pinch injuries.

17. The assembly of claim 13, wherein an aperture in the solder resist allows the connector to be soldered to the conducting layer.

18. The assembly of claim 1, wherein the proximity detection sensor is provided at all edges of the desk surface.

19. The assembly of claim 1, wherein the proximity detection sensor is provided at selected edges of the desk surface.

20. The assembly of claim 1, wherein the system for preventing pinch injuries is battery powered.