# US 5,345,253 A · Track ball base structure

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- Number: US 5,345,253 A
- Document ID: US5345253A
- Status: Granted
- Kind: A
- Application number: 08/184,215
- Filed: 1994-01-21
- Granted: 1994-09-06
- Earliest claimed: 1994-01-21
- Assignees: Behavior Tech Computer Corporation
- Inventors: Douglas Chang
- Web page: https://patentgrep.com/patent/US5345253A

## CPC

- G06F 3/03549: {Trackballs (G06F3/03541 takes precedence)}
- Y10T 74/20201: Control moves in two planes
- G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A track ball base structure comprises a single-piece body having a housing being composed of a plurality of standing plates in the top of the body with extruding portions in the upper end of which to get secure connection to a cover, a central circular recess with an opening bottom to hold a ball therein, a plurality of ball bearing holes evenly distributed around the upper rim of the circular panel in the housing with an inner rectangular plate inside the uppermost of each hole for admitting ball bearings therein and at the same time holding them in place, multiple pairs of locking means and slots in both sides of the body for locking the detecting system as well as fixing the body substantially onto an integrated circuit plate. The present invention is characterized by providing a track ball base structure in a non-assembly manner. Therefore, the number of component parts required for the track ball is reduced and clearly any damage occurring under interconnection for each part can be eliminated.

## Claims

### Claim 1

A track ball base structure comprising a single-piece body having:
a housing to receive a ball and an encoder wheel therein being composed of a plurality of standing plates in the top of said body with extruding portions in the upper end of which to get secure connection to a cover; a central circular recess with an opening bottom to hold said ball therein; a plurality of ball bearing holes evenly distributed around the upper rim of the circular panel in said housing with an inner rectangular plate inside the uppermost of each said hole for admitting ball bearings therein and at the same time holding them in place; two strip slots and the corresponding pairs of locking means working together in order to hold said encoder wheel wherein the holding condition can be enhanced due to a lateral gravity force from said ball if sitting in said central circular recess; two locking holes in platforms outer to said housing through which said single-piece body can be screwed up onto an integrated circuit plate by a bolt; a bracket-shaped fixture in the bottom of said single-piece body being provided to substantially engage with a block on which a photoemitter and a photodetector are located in pair.

### Claim 2 (depends on 1)

A track ball base structure according to claim 1, wherein the couples of said ball bearings and said ball bearing holes are replaced by the same shape of bump which is made of anti-friction material so that a much simpler structure can be formed while the same function retained.