Browse Prior Art Database

Self-Adjusting Caster Leg

IP.com Disclosure Number: IPCOM000035217D
Original Publication Date: 1989-Jun-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 4 page(s) / 91K

Publishing Venue

IBM

Related People

Mott, WE: AUTHOR

Abstract

A self-adjusting caster leg is disclosed which pivots down to contact the floor and support the outer end of a drawer or machine component as it is pulled out for access. The distance that the leg must pivot to contact the floor varies, depending on the mounting height of the machine legs. In order to avoid manual adjustment, the caster leg pivot shaft rotation is constricted by a coil-spring one-way clutch. Thus the caster leg is permitted to freely pivot downward until it touches the floor, in which position it supports the weight of the drawer or component as the one-way clutch prevents contra-rotation. A pawl and ratchet mechanism is deployed as a fail-safe back-up support. As the drawer is returned to its operating position the spring clutch is automatically released and the leg is cammed up into its storage position.

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Self-Adjusting Caster Leg

A self-adjusting caster leg is disclosed which pivots down to contact the floor and support the outer end of a drawer or machine component as it is pulled out for access. The distance that the leg must pivot to contact the floor varies, depending on the mounting height of the machine legs. In order to avoid manual adjustment, the caster leg pivot shaft rotation is constricted by a coil-spring one- way clutch. Thus the caster leg is permitted to freely pivot downward until it touches the floor, in which position it supports the weight of the drawer or component as the one-way clutch prevents contra-rotation. A pawl and ratchet mechanism is deployed as a fail-safe back-up support. As the drawer is returned to its operating position the spring clutch is automatically released and the leg is cammed up into its storage position.

(Image Omitted)

Figure 1 shows an "exploded" view of the present embodiment. Trolley 1 has two sets of rollers on each side. Lower Rollers 2, ride within channel Guides 35 and 37, which are secured to the floor of the enclosure. Upper Rollers 7, ride within channel Guides 36 and 38, which are integral parts of the framework of the subject drawer or machine component.

Angle Plate 4, an integral part of Trolley 1, contains two holes, 5 and 5A which are respectively aligned with two "D"-shaped holes, 3 and 3A. Support Shaft 6 passes through hole 5 and its "D"-shaped end fits into matching hole 3 which thus prevents its rotation. Shaft 6 is captured by retainer 42 which clips into a slot in the shaft.

Spring Clutch Support Arbor 14 is mounted on Shaft 6 with Key 39 inserted in Shaft Keyway 26 and Arbor Keyway 27, preventing rotation of Arbor 14 relative to Shaft 6. The Shaft, Key, and Arbor are locked together by Set Screw 41 through the outer shoulder of the Arbor. Coil Spring Clutch 30 is installed on the hub of Arbor 14 and the end 29 of the Spring Clutch wire coil is inserted in hole 28 in the flange of Arbor 14. This prevents the Spring Clutch from rotating relative to Arbor 14.

Wheel Support Frame 19 includes Spring Clutch Drive Arbor 12 welded in one arm. Support Frame 19 is installed on Shaft 6 so that one side is directly on the shaft beyond Spring Clutch Arbor 14, and the inner shoulder of Drive Arbor 12 is within Coil Spring Clutch 30, in

(Image Omitted)

face to face contact with Support Arbor 14. Drive Arbor 12 is free to rotate on the shaft. However it is constrained by Coil Spring Clutch to rotate in one direction only, the direction that tends to unwind the coil. Spring Clutch Release Lever 11 is positioned on the shoulder of Driving Arbor 12, outside Frame 19. The end 13 of of the Spring Clutch wire coil is inserted in hole 31 of Release Lever 11. Operation of this Lever unwinds Coil Spring 30 slightly releasing Drive Arbor 12 permitting contra-rotation. Wheel 22 is mounted in Frame 19 on Axle 21 and secured by Retainer 44.

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Pawl Release Lever 10 is positioned...