GB2088264A

GB2088264A - Screwing tool attachment

Info

Publication number: GB2088264A
Application number: GB8125776A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-11-28
Filing date: 1981-08-24
Publication date: 1982-06-09
Also published as: GB2088264B

Abstract

The tool (10) comprises a shaft (11) of which one end (12) is held in the jaws of a drill and the other end (13) guides a screw and non-rotatably retains a screwdriver blade (15), allen key, or the like. A screw retaining means comprising inner and outer sleeves (18, 19) surrounds the shaft (11) and blade (15) and is movable axially relative thereto, the sleeves (18, 19) retaining the screw during a screwing operation. The inner (18) and outer (19) sleeves are resiliently biased away from the machine engaging end (12) of the tool (10). Balls (34), retained in apertures (33) in the inner sleeve (18) and movable radially in contact with a stepped conical surface (32) inside outer sleeve (19), allow the head of the screw to pass between them when inner sleeve (18) is retracted into outer sleeve (19) by hand or by the workpiece but grip the shank of the screw whilst screwing is performed. <IMAGE>

Description

SPECIFICATION Tool This invention relates to tools, and in particular to tools for use in tightening or removing screws, bolts or nuts or the like.

In addition to the use of screwdrivers or spanners by hand, it is known to use power tools for the above purpose. The use of power tools in this context is particularly advantageous in the event that a large number of screws, nuts or the like are to be tightened or removed since in such a case the use of hand tools can be arduous and cause discomfort to the person concerned.

However particular difficulty is experienced in the use of power tools in the case of inserting and tightening screws, for example wood screws, into a workpiece or fixture. This is due to the lack of control exercisable by the operator of the power tool on the retention of the tool in or around the screw head and in respect of the direction of intended insertion of the screw into the workpiece or fixture. Also such power tools as have been proposed are expensive and unless they are used frequently such expense is not justified.

It is an object of the present invention to provide means whereby the abovementioned operation can be performed with the use of a power tool in a manner not having the aforementioned disadvantages, or at least in which such disadvantages are substantially reduced.

The invention provides a device for use in rotating a screw or the like comprising elongate engaging means having one end thereof adapted to engage and guide said screw and the other end adapted to be received in the jaws of a rotary machine, a screw driving member located within said one end of said engaging means to be surrounded thereby, and a screw retaining means surrounding said engaging means and said driving member and movable longitudinally relative thereto.

By screw or the like is intended to include screws, for example wood screws, bolts, studs, nuts or the like having a screw threaded portion and having a slot, a recess or an outer form adapted to receive a screwdriver, allen key or spanner for the purpose of tightening or removal of the screw.

Preferably said retaining means is resiliently biased longitudinally of said engaging member.

The said driving member may comprise a screwdriver bit or blade, an allen key or plug, or a socket spanner device. The said other end is preferably of circular cross-section.

The engaging means may have a recess in said one end thereof whereby a head of said screw may be received therein.

The invention will now be further described with reference to the accompanying drawings in which: Figs. 1 to 3 are sectional elevations of one embodiment.

Referring now to Fig. 1 there is shown a tool 10 comprising an elongate engaging member or shaft 11, one end 12 of which is of circular crosssection and may be received in the jaws of a drilling machine (not shown) in conventional manner. The other end 13 of shaft 11 is provided with an axially extending bore 14 of hexagonal cross-section and in which a bit 1 5 is received.

The bit 1 5 shown in Figure 1 is a flat bladed screwdriver and may be replaced by a cruciform screwdriver bit or an allen key bit as required by a screw (not shown) to be tightened or unscrewed.

The bit 1 5 is retained in bore 14 by means of a resilient O-ring 17, bore 14 being of a length such that the free end 13 of shaft 11 is substantially in alignment with the blade of bit 1 5 in order to act as a guiding support for a screw when engaged by the bit 1 5. Preferably the bore 14 is chamfered at the end 13, as shown in Fig. 1, for this purpose.

Inner 18, and outer 19, guide sleeves surround the shaft 11 and bit 1 5 and are movable axially relative thereto and relative to each other. A cap 20 is mounted on shaft 11 and is positionally adjustable axially thereof by means of spigots 21, which are provided on a sleeve 1 6 secured to shaft 11 by a pin 35, engaging in respective ones of a plurality of internal grooves 22 axially extending by differing amounts in cap 20.

Alternatively cap 20 may be screwed onto sleeve 1 6. A spring 23 is located in an annular recess 24 in cap 20 and reacts against a washer 25 which in turn abuts outer sleeve 19, whereby cap 20 and outer sleeve 1 9 are resiliently biased away from each other. Internal circlip 26 in outer sleeve 1 9 abutting outer circlip 27 on sleeve 16 limits the movement of outer sleeve 19 away from cap 20.

A spring 28 is disposed within outer sleeve 19 to react between circlip 27 and an internal rib 29 so as to bias outer sleeve 19 away from end 12 of shaft 11. If cap 20 is screwed to sleeve 1 6 either one of spring 23 or 28 is not required. Inner sleeve 1 8 is resiliently biased away from end 1 2 by a spring 30 and is limited in its axial movement by a rib 31 abutting an internal conical surface 32 of outer sleeve 19. The conical surface 32 is stepped at 38 (more clearly seen in Fig. 2) so as to accommodate a wide range of screw shank diameters with which the tool 10 may be used.

Inner sleeve 18 has four apertures 33 in which balls 34 are retained, the apertures 33 having a lip 36 at the inner edge to prevent the balls 34 from passing therethrough and also maintaining separation of the balls 34 when in their innermost position and not retaining a screw within the tool 10. In this way also a wide range of sizes of screw can be accommodated by the tool 10.

Before use of the tool 10 it is in a configuration as shown in Fig. 1 with inner sleeve 1 8 protruding from outer sleeve 1 9. By pushing inner sleeve 1 8 into outer sleeve 1 9 against the force of spring 30 the head of a screw may be inserted into the tool 10. The balls 34 may move radially outwardly along conical surface 32 to allow the head of a screw to pass therebetween and to engage bit 1 5.

The tool 10 will then be in the configuration substantially as shown in Fig. 2. The spring 30 will then push inner sleeve 18 in the opposite direction so that balls 34 are forced radially inwardly to engage the shank of the screw, the head of the screw being retained in contact with bit 1 5 and guidingly supported by end 13 of shaft 11.

The screw is then offered to the workpiece and screwing commenced. During this operation the screw is securely located by the tool 10 as above described. Eventually the outer end 37 of inner sleeve 1 8 abuts the workpiece and further screwing causes the inner sleeve 1 8 to be retracted into outer sleeve 1 9. Thereafter outer sleeve 1 9 also abuts the workpiece and both sleeves 18, 19 are forced towards end 12. After further insertion of the screw into the workpiece washer 25 abuts cover 20 as shown in Fig. 3.

During the second phase of the screwing operation the retraction of inner sleeve 1 8 into outer sleeve 1 9 allows the balls 34 to move radially outwardly so that the screw is released and the head of the screw can again pass between balls 34.

When the-situation as shown in Fig. 3 is reached the bit 1 5 will disengage from the screw and screwing will cease. In consequence the axial location of cap 20 relative to sleeve 16 determines the height of the head of the screw relative to the workpiece at the termination of screwing. By adjustment of cap 20 axially of sleeve 1 6 it can be arranged accurately, easily and conveniently, that the head of the screw be proud of, flush with or recessed relative to the surface of the workpiece. In the Figures the cap 20 is shown in a position of adjustment for which the screw head will be recessed into the workpiece by a small amount.

By means of the invention a large range of sizes of screw may be securely retained and guided by the tool 10 during a screwing or unscrewing operation.

Claims

1. A device for use in rotating a screw or the like, said device comprising elongate engaging means having one end thereof adapted to engage and guide said screw and the other end adapted to be received in the jaws of a rotary machine, a screw driving member located within said one end of said engaging means to be surrounded thereby and a screw retaining means surrounding said engaging means and said driving member and movable longitudinally relative thereto.

2. A device according to claim 1 wherein said retaining means is resiliently biased longitudinally of said engaging means.

3. A device according to claim 1 or claim 2 wherein said driving member comprises a screwdriver blade.

4. A device according to claim 1 or claim 2 wherein said driving member comprises an allen key.

5. A device according to any one of claims 1 to 4 wherein said other end is of circular crosssection.

6. A device according to any one of claims 1 to 5 wherein said engaging means has a recess in said one end, said recess being adapted to receive a head of said screw therein.

7. A device according to any one of claims 1 to 6 wherein said retaining means is resiliently biased in an axial direction from said other end to said one end.

8. A device according to claim 7 wherein said retaining means comprises inner and outer sleeve members which are relatively movable axially of said device.

9. A device according to claim 8 wherein said inner sleeve member has at least one aperture therein, and comprising a movable member retained in the or each aperture for movement therein radially of said device.

10. A device according to claim 9 wherein said inner sleeve member has therein a plurality of equi-angularly spaced apertures, each aperture having a lip at the innermost end thereof whereby said movable members are prevented from passing through said apertures and from mutual contact when in their innermost positions.

11. A device according to claim 9 or claim 10 wherein said outer sleeve member comprises an inner conical surface which in use is engaged by the or each movable member.

1 2. A device according to claim 11 wherein said conical surface is stepped.

13. A device according to any one of claims 7 to 12 comprising stop means disposed on said engaging means so as to limit the movement of said retaining means in a direction towards said other end.

14. A device according to claim 13 wherein said stop means comprises a cap the position of which is adjustable axially of said engaging means.

15. A device according to claim 13 or claim 4 wherein said retaining means and said stop means are resiliently biased away from each other.

16. A device according to any one of claims 1 to 1 5 wherein said driving member is adapted to be non-rotatably received in a socket portion of said one end of said engaging means.

1 7. A device for use in rotating a screw member substantially as hereinbefore described with reference to and as illustrated in any one of the various figures of the accompanying drawings.