US2726449A

US2726449A - Locking device for dental drill hand pieces

Info

Publication number: US2726449A
Application number: US435420A
Authority: US
Inventors: Louis W Tirocchi
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-06-09
Filing date: 1954-06-09
Publication date: 1955-12-13
Anticipated expiration: 1972-12-13

Description

Dec. 13, 1955 L, w, cc 2,726,449

LOCKING DEVICE FOR DENTAL DRILL HAND PIECES Filed June 9, 1954 III; ,1114 .psm

1N VEN TOR.

BYJL'A K 7% /,//M'/ 754* United States Patent LOCKING DEVICE FOR DENTAL DRILL HAND PIECES Louis W. Tirocchi, Providence, R. 1.

Application June 9, 1954, Serial No. 435,420

2 Claims. (CI. 32-27) The present invention relates to contra-angle dental drill handpieces and has particular reference to a novel locking device therefor.

The usual construction for a contra-angle dental drill handpiece includes a casing housing reduction gears and having a spindle sleeve with a central drill receiving bore, the drill being provided with an annular slot for receiving a releasable locking member. The standard type includes a casing having a slit for receiving a pivoted lock latch, which is adapted to be swung in alignment with the drill handle for locking the drill, and to be swung laterally through the slot for releasing the drill. The locking latches heretofore used have been found difiicult to manipulate with one hand, and are thus inconvenient when drills must be quickly changed.

It is the principal object of the invention to provide a novel drill locking latch which can be readily manipulated by the thumb when the handpiece is being held, thus facilitating removal of one drill and insertion of another.

Another object of the invention is to provide a drill locking latch which has a thumb piece extending substantially above the handpiece parts, so that the locking and unlocking operations can be carried out by touch.

A further object of the invention is to provide a simple locking latch for replacing swivel type latches.

With the above and other objects and advantages features in view, the invention consists of a novel arrangement of parts more fully disclosed in the detailed description following, in conjunction with the accompanying drawings, and more specifically defined in the claims appended thereto.

In the drawings,

Fig. 1 is a side view of a standard type of drill handpiece, equipped with the novel locking latch;

Fig. 2 is an enlarged detail thereof, parts being broken away to disclose the locking latch and the parts associated therewith;

Fig. 3 is a top plan view of Fig. 2, parts being broken away; and

Fig. 4 is a perspective view of the novel locking latch.

It has been found desirable to provide a locking latch of the slide type for replacement of the standard type swivel latch, and to form the latch so that it may be readily shifted by the fingers of the hand holding the dental handpiece, whereby a simple and convenient means is afforded for rapid changing of drills.

Referring to the drawings, the illustrative dental hand ICC piece 10 includes a handle 11 having a head 12 containing standard contra-angle gears, including a rotatable spindle sleeve 13 for detachably receiving a drill or burr 14 with a standard shaft key flat.

The head 12 has a cover 15 which is spaced above the body of the head to provide a clearance slot 16, the cover having a raised portion 17 which forms a housing 18 into which the upper end of the drill 14 extends, whereby the annular lock groove 19 provided at the upper end of the drill is positioned in alignment with the clearance slot.

A locking latch 20 of resilient metal is slidably positioned in the clearance slot, and includes a fiat body portion 21 having an elongated opening 22, whereby a set screw 23, see Fig. 2, may extend through a suitable opening in the cover and loosely through the opening 22 to threadedly seat in the head body; the outer end 24 of the latch body portion has a U-shaped slide recess 25 which is adapted to seat into the annular drill lock groove sides when the latch 20 is pushed forwardly; the inner end 26 of the latch body portion is extended into a roll 27 of substantial size, the axis of the roll 27 being in line with the plane of the latch body portion, whereby the roll seats into the usual reduced handle portion 28 and extends above and below the head cover, as illustrated in Fig. 2, and is resiliently pressed upwardly by contacting handle portion. If desired, the body portion of the latch may be provided with a small oil hole 29 to receive lubricating oil. The roll 27 is preferably concave on its lower surface 30, to conform to the curvature of the reduced handle portion 28 for resisting side movement.

When the dentist grasps the handpiece in the usual manner, the thumb is in a position to extend over the latch roll for pulling the latch back to release the drill, whereby the free hand of the dentist is available to get the released drill and to replace it with a new drill; the thumb then pushes the roll forwardly to lock the drill in place.

Although I have disclosed a specific embodiment of the invention, it is obvious that changes in the size, shape and proportion of the parts in accordance with different sizes, shapes and proportions of hand pieces, may be made without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. A locking latch for a dental contra-angle hand piece having a reduced cylindrical handle portion, having a fiat body portion, an elongated opening in said body portion, a U-shaped slide recess at one end of the body portion, and a roll at the other end of the body portion, said roll having its axis in the plane of the body portion and being of a size to extend substantially above and substantially below the plane of the body portion, the roll being concave on its lower surface to conform to the curvature of the handle portion.

2. In the locking latch of claim 1, said body portion having an oil hole.

References Cited in the file of this patent UNITED STATES PATENTS