Caster attachment system

A caster attachment system includes an upper section and a lower section. The upper section mounts to a piece of equipment. The lower section provides a post for the mounting of a caster. A shaped key on the lower section fits within a receiver socket on the upper portion. The upper section and the lower section are held together by a threadable connection.

FIELD

The present invention pertains to casters; more particularly, the present invention pertains to a caster attachment system used with a medical/surgical system such as a vitrectomy system.

BACKGROUND

In prior art medical/surgical systems, the interface between a directional caster and a supported structure was typically done with a keyed caster that extended through the structure and was secured with a locking nut disposed within the system. It has been found that some designs of equipment will not provide sufficient access to secure a caster with a locking nut in this manner. In addition, such a locking nut makes it more difficult for field service personnel to assemble and service equipment at the customer site. There is therefore a need in the art for a caster attachment system that will allow the caster to be easily secured from the outside of the system.

SUMMARY

The disclosed caster attachment system enables a caster to be secured to a piece of equipment from the outside using just a simple wrench.

The disclosed caster attachment system includes an upper section and a lower section. The upper section is connectable to the bottom of a piece of medical/surgical equipment. The upper section further includes a shaped opening formed therein and externally formed threads surrounding the shaped opening.

The lower section includes a caster mounting post. Substantially aligned with the caster mounting post is a shaped key member. A floating nut engages a collar surrounding the shaped key member.

By threadably connecting the floating nut to the externally formed threads on the upper section and tightening the connection with a wrench, the caster is secured to the piece of equipment.

DESCRIPTION OF THE EMBODIMENTS

The caster attachment system10for use with a medical/surgical system such as a vitrectomy system provides an alternative method for attaching and removing casters100. The disclosed caster attachment system10allows directional locking casters to be secured to the supported structure from the exterior of the medical/surgical system.

As shown inFIG. 1, the attachment fitting used in the disclosed caster attachment system10includes two separate portions20,40. The first portion20is mounted to the bottom exterior of the medical/surgical equipment.

The first or top portion20of the caster attachment system10includes a receiver socket22. Surrounding the receiver socket22is an externally threaded portion24to interface with the floating nut44explained below. The receiver socket22is secured to the supported piece of medical/surgical equipment with a threaded interface25or it can be mounted using nuts28, bolts, pins, insert molded or a cast in feature. Mating anti-rotation features prevent rotation of the second or lower portion40with respect to the upper portion20. Such features may preferably include a machined key feature wherein the machined key and its mating socket have at least one flat side; a set of pins passing through an aligned set of holes30,50; and/or fasteners.

The second or bottom portion40of the caster attachment system10includes a caster post42attached to the caster100. The caster post or shaft42is secured to the upper portion20using a captive nut44. The floating nut44is trapped on the caster post42. The inner diameter of the nut44is larger than the outer diameter of the shaft42. This difference in diameters allows the captive nut44to float about shaft42and to accommodate any misalignments. A flange46is formed around the caster post42of the lower portion40for contact with the interior of the floating nut44. Above the flange46is the male portion or key48which fits into the receiver socket22.

The disclosed caster attachment system takes up very little space. A simple wrench selected to fit on floating nut44is used to couple and decouple the unit from the supported medical/surgical equipment. Those of ordinary skill in the art will understand that the caster attachment system may be accessed from the outside of the supported system and a minimum of parts are used.

As may be seen by the foregoing, a receiver socket22is used with an integrated threaded fastening system and a matching keyed pin with a floating nut. The receiver socket portion22of the caster attachment system can either be mechanically attached with a nut28, or the receiver socket22can be insert molded. When the two portions20,40of the caster attachment system10are joined, the keyed feature controls orientation of the caster100and the floating nut44secures the joint to create a structurally sound interface with the supported structure. If desired a mechanical lock such as a ball and socket my be used to hold the male key48within the receiver socket22while the floating nut44threadably engages the external thread24.

While the disclosed invention has been described according to its preferred embodiment, those of ordinary skill in the art will understand that numerous other embodiments have been enabled by the foregoing disclosure. Such other embodiments shall be included within the scope and meaning of the appended claims.