GB2223977A

GB2223977A - Dental tool with interchangeable applicator heads

Info

Publication number: GB2223977A
Application number: GB8921766A
Authority: GB
Inventors: Holger Fitjer
Original assignee: Georg Karl Geka Brush GmbH
Current assignee: Georg Karl Geka Brush GmbH
Priority date: 1988-09-27
Filing date: 1989-09-27
Publication date: 1990-04-25
Also published as: DE3832694A1; DE3832694C2; DE3832694C3; GB8921766D0

Description

- 1 22239-77 DENTAL TOOL WITH INTERCHANGEABLE APPLICATOR HEADS This

invention relates to a dental tool with interchaneeable applicator heads, which tool is useful for cleaning of spaces between teeth in the mouth and for oral hygiene and cleaning of dentures, and for cosmetic dental use, including use by dental surgeons in dental treatment and by technicians in dental labora tories.

For such DurDoses there is a need for an aPD1ictor tool of which the head can be in the form of a whisk, brush or swab all for carrying a liquid, powdery or cosmetic cleaning- agent or a probe or the like for dental surzeon, which head is ensured to be kept in sterile hygienic condition until needed and which does Tiot cause any risk to the health of the user or contamination of the working area when the tool has used. To meet these requirements such tools have been generally provided with the head united with its handle, all in a sterile wrapping, and after use the entire tool is thrown away rather t'han having the entire tool resterilised.

It is an object of the invention to provide such a tool the handle of which can be reused, and wherein the applicator or other type of head is dis posable and can be attached in a releasably locking manner, and preferably the working portion of the head does not have to be touched by hand either when being attached or detached, so that it remains sterile and non-contaminating.

According to the invention we provide a tool for dental use with at least one interchangeable head, e.g. an applicator, in which the head is slidably engagable and disengagable with one end of the holding portion (handle) of the tool and is retained therein by engagement of a terminal portion of the shank of said head with a correspondingly shaped portion of the end of said holding portion, locking means being provided which are mutually engagable and disengagable by a finger of an operator at the end of said holding portion.

The holding portion or handle of the tool is usually elongated in known manner, may have a gripping portion and may be bent along its length, especially near the engagement of the replacable head.

In one embodiment of the invention, the locking means is provided by an inwardly directed springy tongue being formed in the handle end which is engagable in a recess in the portion of the interchangeable head, preferably so that the end of the tongue acts as a locking lug which engages in a correspondingly formed recess in the head, and preferably by twisting the head about its longitudinal axis the tongue is displaceable from its locking or detent position so that the head is removable. The locking lug preferably has a rear edge directed substantially perpendicular to the axis of insertion of the shank of the applicator or other type of head, and is engagable against a similar surface of the recess in the enlarged terminal portion of the head, the remainder of the lug being in the shape of a wedge. The head to be engaged into a tool is pushed into the recess, at the side of which the locking lug is present, so as to first push the lug outwardly and then to allow the lug to snap into place in the recess so as to firmly hold the head in position. The head is releasable by being rotated through about 90' so that the locking tongue is pushed out of the recess by the rotation and the head can then be pulled out.

Preferably a knurled wheel is provided on the shank of the head to facilitate this turning movement 1 3 - in a clean and hygienic manner; such a wheel is pref er ably provided in a position on the shank side just below the enlarged head of the shank, so that when the tool is in position the wheel lies just below the end of the handle of the tool.

The springy tongue can conveniently be formed by making a U-shaped cut into the side of the end of handle so that the free ends of the U are still at a short distance from the front edge of the end of the handle and a flexible cross piece of material remains by which the free end of the tongue is supported.

Alternatively, the preceding described embodiment can be generally reversed, and instead of a female ending to the handle into which the male attachment portion of the interchangeable head is inserted, the end of the handle is received in a cup-like terminal portion of the head, with corresponding retention means being provided, such as a resilient projection or tongue which extends from the end of the head through a hole or slot in said cup-shaped portion of the head; the resilient projecting member can suitably be L-shaped so as to present two ramped surfaces which fit into a corresponding slot and the member being mounted from the end of the handle so as to be displaceable by the uers's finger into a recess within the handle, whereupon the head can be readily pulled off.

In both described embodiments the user's finger is kept away from the working portion of the head (e.g. an applicator), so that this portion remains sterile and the finger which is used is not soiled.

In the latter embodiment the cup-shaped terminal portion of the head end and the corresponding free end of the handle are preferable correspondingly tapered conically so as to fit easily together.

In a further embodiment, the interchangeable head and the free end of the handle are connected by placing a hook or eye on one of such members over a projecting pin or spigot on the other, most suitably an eye at the end of the shaft of the interchangeable head is arranged to be placed upon a corresponding short pin or spigot projecting from the side of the end of the handle, and the eye is secured by the closing of a small hinged portion also provided at the end of the handle and which can readily be opened or closed by the user's finger; said cover may have a throughhole or recess for receiving the end of said pin or spigot. A groove should be provided inthe end of the handle or cover or both thereof for receiving the shaft of the interchangeable head so as to firmly retain it against sideways movement.

This last embodiment is particularly suitable for use where the interchangeable head is a brush made of a plurality of twisted wires which are brough together as the shaft of the head, the eye being formed by bending the free end of this shaft, the parallel wires being connected to each other so that a separate supporting shaft is unnecessary. A head could be provided with a bifurcated shaft so as to have two hooks or eyes placed respectively over two pins on the end of the handle, for greater rigidity. The applicator shaft and/or the end of the handle can be bent at an angle so as to obtain the desired placing of the working portion of the head in use.

Alternatively the end of the shaft of the inter- changeable head can be formed as a T which fits into a corresponding recess in the end of the handle and is retained therein by the closure of hinged cover thereover.

The handle or part thereof may be made of synthetic plastics material, and in the last embodiment this is advantageous to allow the hinged cover to be resiliently retained by the snap fitting of corresponding small projections and recesses of the cover and opposing portion of the head The hinging of the cover 'can be by means of a film or thin continuous portion of a single plastics molding.

The invention is further described by reference to the several preferred embodiments shown by way of illus- tration in the accompanying drawings, in which:

Fig. 1 is a perspective view of an interchangeable applicator tool according to the invention; Fig. 2 is a perspective view of Fig. 1 modified by angling the handle; Fig. 3 is a longitudinal section through the front end of the tool of Fig. 1 or 2 with the applicator head locked in the working position; Fig. 4 is a view as in Fig. 3 but with the head turned through 90' in partly pulled out position from the recess in the handle; Fig. 5 is a side view of the end of the handle and the interchangeable applicator head of a second embodiment; Fig. 6 is a view as in Fig. 5 but with head separated from the handle of the tool; Fig.7 is a longitudinal section taken along the line VII-VII in Fig. 5 through the assembled tool; Fig. 8 is a perspective view of the head end of a third embodiment of an applicator tool according - 6 to the invention in its assembled position; Fig. 9 is a view corresponding to Fig. 8 but with the clamping cover unfolded open; Fig. 10 is a view as in Fig. 9 with unhooked applicator; and Fig. 11 is a longitudinal section of the end of the handle portion along the line XI-XI in Fig. 8.

In any of the embodiments, the handle of the tool may be shaped as shown in Fig. 1 or 2, namely having a straight stem 1, preferably with slightly raised gripping panels 3 to allow a good hold and a straight terminal portion as in Fig. 1 or an angled portion as in Fig. 2. The interchangeable applicator head 4 is illustrated as having rotary brushes 5, although the head can have any other desired form and function.

In the embodiment shown in Figs. 1 to 4, the shank 6 of the head is enlarged cylindrically and is held in a corresponding recess which is a cylindrical bore 7 in the end of the handle, and is retained therein by a springy tongue 8 formed as portion in the end of the handle 7,- the attachment of the tongue the front edge 9 of the recess 7.

a U-shaped punched out surrounding the recess 8 is spaced away from - 7 This springgy tongue is in the form of a wedge shaped locking lug 11 angled inwards, whereby if desired it could also be provided that the springy tongue lies in the plane of the sleeve and carries on the inner side a corresponding wedge-formed lug 11. This wedge-formed lug 11 with a rear edge 12 directed substantially perpen dicular to the axis of insertion catches in a correspond ingly formed cut-out portion 13 of the supporting shank.

With the help of a knurled band 14 formed of a rotary portion 1, the applicator can be very simply inserted where by first the springy tongue is turned outwards and then self engaged in the hollow 13. To release it again, the knurled band 14 is turned in the direction of the double arrow 15 in one or other direction through 90', by means of which the springy tongue 10 with its locking lug 11 is displaced outwards so that the shank in this way becomes free and, as shown in Fig. 4, can simply be pulled out forwards.

In the embodiment of Figs. 5 to 7, the supporting 20 shank 6' of the applicator 4 is moreover at its rear formed into an enlarged sleeve in which the corresponding head end 2' of the handle 1 ' is insertable. This head end 2' is, at its front end, for its part formed as a sleeve whereby between two sideways extending longitudinal slits 16 is formed a springy tongue 17 with a wedge-shaped lug 18 having two ramp edges 19 and 20 inclined to the longitudinal - 8 axis. This lug 18 is engaged sleeve-shaped supporting shank as a consequence of insertion 19 of the springy tongue 17 shaped lug 18 can spring out corresponding traction over by previous pressure on the in a through-hole 21 of the 6 of the applicator, whereby a tilting of the ramp edges takes place until the wedge of the through-hole 21. By the ramp edge 20, likewise wedge-shaped lug 18 in the direction of the arrow 22, an unlocking results.

In the Figs. 8 to 11 are representations of a third embodiment according to the invention of an applicator tool, the head end 2" is divided in a plare passing through almost the longitudinal insertion axis so that a rigid head end section 23 and a cover 25 is formed pivotable about, for example, a film hinge between which the supporting shank C of the applicator C is clampable. The supporting shank 6" is thereby provided with an attached eye 26 which is hookable on a pin 27 of the rigid head end section whereby the pin 27 projects into an aperture 28 upon closing of the cover 25. This can happen through corresponding operation simultaneously of a clamping locking device to put the cover into the closed position, in which connection obviously also still further locking means could be provided. A channel-shaped depression 29 in the rigid head end section 23 and likewise in the cover 25 serves for secure guidance of the supporting shank C.

Variations of the arrangements shown in Figs. 8 to 11 could also be provided, with the supporting shank C provided with an angled end, likewise with two T-formed 1 supporting cross pins which are hookable upon corresponding removal of the rigid head end section 23, or the cover 25.

Claims

CLAIMS:

1. A tool for dental use with at least one interchangeable head, in which the head is slidably engag able and disengagable with one end of the handle for holding the tool and is retained therei n by engagement of a terminal portion of the shank of said head with a correspondingly shaped portion of the end of said handle, locking means being provided which are mutually engagable and disengagable by a finger of an operator at the end of said handle.

2. A tool as claimed in Claim 1, wherein the handle of the tool is elongated and is bent along its length.

3. A tool as claimed in Claim 1 or 2, wherein the locking means is provided by an inwardly directed springy tongue being formed in the handle which is engagable in a recess in the end portion of the interchangeable head.

4. A tool as claimed in Claim 3, wherein the end of the tongue acts as a locking lug which engages in a correspondingly formed recess in the head.

5. A tool as claimed in Claim 3 or 4, where-in by twisting the head about its longitudinal axis the tongue is displacable from its locking or detent position so that the head is removable.

6. A tool as claimed in Claim 4 or 5, wherein the locking lug has a rear edge directed substantially perpendicular to the axis of insertion of the shank of the interchangeable head, and is engagable against a similar surface of the recess in the enlarged terminal portion of the head, the remainder of the lug being in the shape of a wedge.

4 - 11

7. A tool as claimed in any of Claims 3 to 6, wherein the springy tongue is formed as a U-shaped punched out portion in the side of the recess in the end of the handle.

8. A tool as claimed in any of Claims 3 to 7, wherein a knurled wheel is provided on the shank of the interchangeable head to allow turning of the head by the finger of the operator in order to disengage said locking tongue.

9. A tool as claimed in Claim 1 or 2, wherein the interchangeable head has a cup-like terminal portion into which the correspondingly shaped terminal portion of the handle is fitted.

10. A tool as claimed in Claim 9, wherein a resilient projection is provided on said terminal portion of the handle which extends through a corresponding aperture in the terminal portion of said head.

11. A tool as claimed in Claim 10, wherein said projection is a resilient lug with inclined up- standing surfaces which allow the head to be pushed onto or pulled off from the handle.

12. A tool as claimed in Claim 1 or 2, wherein the locking means comprises a mutual attachment means of the head and handle and a hinged locking means which fits over said attachment.

13. A tool as claimed in Claim 12, wherein said attachment means is a hook-and-eye attachment.

14. A tool as claimed in Claim 13, wherein said attachment means is an extension transverse of the shank of the head which fits into a transverse recess in the end of the handle.

15. A tool as claimed in Claim 12, 13 or 14, which includes an axial groove in the end of the handle for receiving the shank of the heads.

16. A tool as claimed in any preceding claim, wherein the head is a small brush formed of twisted wires.

17. A tool as claimed in Claim 16 as dependent on Claim 13, wherein the wires are twisted to form the shank of the head which is bent to form an attachment eye.

18. A tool for dental use with an interchangeable head, substantially as hereinbefore described with reference to Figs. 1 to 4, 5 to 7 or 8 to 11 of the drawings.

Published 1990 at The Patent Office. State House, 66!71 High Holborn, London WC1R 4TP. Further copies inaybe obtained from The Patent Office Wes Branch, St Mary Cray, Orpington. Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent, Con. V87