Ratcheted pivot

• US 6,354,549 B2
• Filed: 11/02/1999
• Issued: 03/12/2002
• Est. Priority Date: 11/02/1999
• Status: Expired due to Fees

• Current Assignee: Ergotron Incorporated (Melrose Industries Plc)
• Original Assignee: Ergotron Incorporated (Melrose Industries Plc)
• Inventors: Sweere, Harry C., Scheller, Dennis M, Fluhrer, Robert W.
• Primary Examiner(s): Braun, Leslie A.
• Assistant Examiner(s): Wujciak, A. Joseph
• Application Number:
  US09/432,331
• Publication Number:
  US 20010050327A1
• Time in Patent Office: 861 Days
• Field of Search: 248/292.12, 248/292.13, 248/220.22, 248/292.14, 248/220.21
• US Class Current: 248/292.14
• CPC Class Codes: F16C 11/045 with at least a pair of arms pivoting relatively to at least one other arm, all arms being mounted on one pin crank-pins F16C11/02
• CPC Class Codes: F16M 11/10 around a horizontal axis F16M11/12 takes precedence
• CPC Class Codes: F16M 13/02 for supporting on, or attaching to, an object, e.g. tree, gate, window-frame, cycle
• CPC Class Codes: F16M 2200/024 by positive interaction, e.g. male-female connections

Abstract

Ratcheted pivot incorporating large and small areas of frictional contact and a ratcheting mechanism to provide for rotational repositioning of a mounting plate and a load about a horizontal axis.

Claims

1. A pivot system, comprising:

a first mounting plate, having a hinge axis;

a second mounting plate operatively connected to the first mounting plate, the second mounting plate rotating relative to the first mounting plate about the hinge axis;

a first sliding friction device coupled to the first and second mounting plates, the first sliding friction device imposing a first direction rotation resistance on the first and second mounting plates; and

a second sliding friction device, coupled to the first and second mounting plates, imposing a second direction rotation resistance on the first and second mounting plates that is less than the first direction rotation resistance.

2. The pivot system of claim 1, wherein the first sliding friction device comprises a first friction washer and the second sliding friction device comprises a second friction washer.

3. The pivot system of claim 2, wherein the first friction washer has a smaller contact area than the second friction washer.

4. The pivot system of claim 2, wherein the first and second friction washers comprise a polymer material.

5. The pivot system of claim 4, wherein the polymer material comprises ultra high molecular weight polyethylene.

6. A pivot system, comprising:

a first mounting plate, having a hinge axis;

a second mounting plate operatively connected to the first mounting plate, the second mounting plate rotating relative to the first mounting plate about the hinge axis;

a toothed array, having a plurality of teeth, the toothed array rotating about the hinge axis;

a tooth engaging device located adjacent to the toothed array that engages the teeth of the toothed array such that only a first direction of rotation of the toothed array is permitted;

a first sliding friction device, coupled to the first and second mounting plates, imposing a first direction rotation resistance on the first and second mounting plates; and

a second sliding friction device, coupled to the first and second mounting plates, imposing a second direction rotation resistance on the first and second mounting plates that is less than the first direction rotation resistance.

7. The pivot system of claim 6, wherein the toothed array comprises a ratchet array.

8. The pivot system of claim 6, wherein the toothed array is located along the hinge axis and between the first mounting plate and the second mounting plate.

9. The pivot system of claim 6, wherein the tooth engaging device comprises at least one pawl.

10. The pivot system of claim 8, wherein the tooth engaging device further comprises a spring, and the spring forces the pawl against the ratchet array.

11. The pivot system of claim 10, wherein the spring and pawl are integrally formed.

12. A method of pivoting a workpiece comprising:

attaching a first mounting plate to a foundation, the first mounting plate having a first pivot surface;

attaching a second mounting plate to a workpiece, the second mounting plate having a second pivot surface;

attaching a dual resistance sliding friction pivot between the first mounting plate and the second mounting plate;

rotating the workpiece in a first direction, the rotation being resisted by a first frictional force; and

rotating the workpiece in a second direction, the rotation being resisted by a second frictional force greater than the first frictional force.

13. The method of pivoting a workpiece of claim 12, wherein attaching the dual resistance sliding friction pivot comprises:

placing a ratchet array between the first and second pivot surfaces; and

attaching a ratchet engaging device adjacent to the ratchet array, the ratchet engaging device only allowing rotation of the ratchet array about the axis of rotation in one direction.

14. The method of pivoting a workpiece of claim 13, wherein attaching the dual resistance sliding friction pivot further comprises:

selecting a first friction material and a second friction material;

placing the first friction material in contact with the first pivot surface and the ratchet array;

placing the second friction material in contact with the second pivot surface and the ratchet array.

15. The method of pivoting a workpiece of claim 14, wherein attaching the dual resistance sliding friction pivot further comprises fastening the first pivot surface, the first friction material, the ratchet array, the second friction material, and the second pivot surface together with a fastening assembly that defines an axis of rotation.

16. The method of pivoting a workpiece of claim 15, wherein fastening the first pivot surface, the first friction material, the ratchet array, the second friction material, and the second pivot surface together comprises fastening with a bolt and a nut.

17. The method of pivoting a workpiece of claim 14, wherein selecting the first friction material comprises selecting a first polymer washer and selecting the second friction material comprises selecting a second polymer washer.

18. The method of pivoting a workpiece of claim 17, wherein selecting the first polymer comprises selecting a first polymer washer having a first contact area, and selecting the second polymer washer comprises selecting a second polymer washer having a second contact area that is larger than the first contact area.

19. A pivot system comprising:

a mounting plate;

an assembly of components comprising;

a first pair of pivot brackets defining a pivot axis, the first pair of pivot brackets attached to the mounting plate;

a first pair of ultra high molecular weight polyethylene (UHMWPE) washers located along the pivot axis and between the first pivot brackets;

a pair of spring washers located along the pivot axis and between the first pair of UHMWPE washers;

a pair of ratchet arrays located along the pivot axis and between the pair of belleville washers;

a second pair of UHMWPE washers having a larger contact area than the first pair of UHMWPE washers, the second pair of UHMWPE washers being located along the pivot axis and between the pair of ratchet arrays;

a second pair of pivot brackets located along the pivot axis and between the second pair of UHMWPE washers;

a bolt and nut fastening the assembly of components along the pivot axis; and

a pawl assembly attached to the mounting plate, the pawl assembly engaging the pair of ratchet arrays and only allowing rotation of the pair of ratchet arrays in one direction about the