Creep mitigation in ball-bearing systems

Patent metadata

Field	Value
Publication number	US-2023122116-A1
Application number	US-202117504439-A
Country	US
Kind code	A1
Filing date	Oct 18, 2021
Priority date	Oct 18, 2021
Publication date	Apr 20, 2023
Grant date	—

Abstract

A head-mounted display includes a varifocal actuation block and an optics block coupled to the varifocal actuation block. An anti-creep system located in the varifocal actuation block includes a plurality of anti-creep mechanisms that are configured to prevent bearing ball creep associated with bearing balls in the varifocal actuation block. The bearing balls are used to move a movable carriage that is coupled to a fixed carriage in the head-mounted display via the anti-creep mechanism. The anti-creep mechanisms prevent bearing ball creep associated with the bearing balls from occurring in the varifocal actuation block by limiting the movement in an angular direction of the bearing balls that are used to move the movable carriage in a first direction in the head-mounted display.

First claim

What is claimed is:

1 . An apparatus, comprising:
a movable carriage; and a fixed carriage coupled to the movable carriage via an anti-creep mechanism, wherein an angular movement of the anti-creep mechanism by the movable carriage prevents a bearing ball from experiencing bearing ball creep.

2 . The apparatus of claim 1 , wherein:
the anti-creep mechanism limits a movement of the bearing ball to one-half of a movement of a movement control pin that is coupled to the movable carriage.

3 . The apparatus of claim 2 , wherein:
the anti-creep mechanism is coupled to the movable carriage using the movement control pin.

4 . The apparatus of claim 3 , wherein:
the movement control pin is configured to control the angular movement of the anti-creep mechanism.

5 . The apparatus of claim 4 , wherein:
the anti-creep mechanism includes a movement control slot, the movement control slot being configured to allow the movement control pin to control the movement of the anti-creep mechanism.

6 . The apparatus of claim 5 , wherein:
the anti-creep mechanism includes a fixed carriage slot, the fixed carriage slot being configured to be coupled to the fixed carriage.

7 . The apparatus of claim 6 , wherein:
a bearing ball slot located at a central location of the anti-creep mechanism is configured to constrain the bearing ball during the angular movement of the anti-creep mechanism.

8 . The apparatus of claim 7 , wherein:
in order to move the anti-creep mechanism angularly in a first direction, the anti-creep mechanism is coupled to an anchor pin that is coupled to the fixed carriage.

9 . A method, comprising:
positioning a bearing ball slot centrally on an anti-creep mechanism such that a bearing ball is located within the bearing ball slot of the anti-creep mechanism; and moving the anti-creep mechanism angularly in a first direction with respect to an anchor axis to prevent the bearing ball from experiencing bearing ball creep.

10 . The method of claim 9 , wherein:
in order to prevent the bearing ball from experiencing the bearing ball creep, the anti-creep mechanism limits the bearing ball to a bearing ball movement in the first direction that is one-half of a movement control pin distance that a movement control pin coupled to the anti-creep mechanism moves in the first direction.

11 . The method of claim 10 , wherein:
the movement of the anti-creep mechanism in the first direction is controlled by the movement control pin.

12 . The method of claim 11 , wherein:
the movement control pin moves from a first movement control position to a second movement control position.

13 . The method of claim 12 , wherein:
the bearing ball movement is from a first bearing ball position to a second bearing ball position.

14 . The method of claim 13 , wherein:
in order to move the anti-creep mechanism angularly in the first direction, the anti-creep mechanism is coupled to an anchor pin located on the anchor axis.

15 . The method of claim 14 , wherein:
the anchor pin is coupled to a fixed carriage and the movement control pin is coupled to a movable carriage.

16 . A head-mounted display, comprising:
a varifocal actuation block; and an optics block coupled to the varifocal actuation block, wherein an anti-creep system located in the varifocal actuation block uses an anti-creep mechanism to prevent bearing ball creep from occurring in the head-mounted display.

17 . The head-mounted display of claim 16 , wherein:
a movement control pin coupled to a movable carriage moves the anti-creep mechanism angularly in a first direction.

18 . The head-mounted display of claim 17 , wherein:
the anti-creep mechanism limits a distance a bearing ball positioned within a bearing ball slot of the anti-creep mechanism moves in the first direction to one-half of a distance a movement control pin moves in the first direction.

19 . The head-mounted display of claim 18 , wherein:
in order to move the anti-creep mechanism angularly in the first direction, the anti-creep mechanism is coupled to an anchor pin that is coupled to a fixed carriage.

20 . The head-mounted display claim 19 , wherein:
the movable carriage is used to move the optics block in the first direction while controlling the movement of the anti-creep mechanism.

Assignees

• Meta Platforms Inc

Inventors

• Smith Clinton

Classifications

• F16C33/586

  outside the space between the races, e.g. end faces or bore of inner ring · CPC title

• G02B7/10 Primary

  by relative axial movement of several lenses, e.g. of varifocal objective lens · CPC title

• F16C2380/00

  Electrical apparatus · CPC title

• G02B27/0176 Primary

  characterised by mechanical features · CPC title

• F16C29/045

  having rolling elements journaled in one of the moving parts · CPC title