GB2251196A

GB2251196A - Screwdriver shroud

Info

Publication number: GB2251196A
Application number: GB9024166A
Authority: GB
Inventors: Victor Hickman
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-10-25
Filing date: 1990-11-07
Publication date: 1992-07-01
Also published as: GB9023227D0; GB9024166D0

Abstract

A shroud 5 for a manually-driven screwdriver comprises a rigid, substantially tubular open-ended body internally dimensioned to accommodate the tip 3 of the screwdriver and the head of a screw such that, in use, the screw is constrained into substantial axial alignment with the screwdriver and the screw may be rotated within the shroud and driven therefrom through a first open end 7 of the shroud, the opening of the other end of the shroud being of reduced diameter to fit closely around the shank 2 of the screwdriver. Resilient biasing means 8 is fitted to the shank of the screwdriver to bias the shroud 5 toward the tip 3 to initially cover the tip. <IMAGE>

Description

SCREWDRIVER SHROUD Field of the Invention The present invention relates to a screwdriver shroud, and more particularly to a shroud for a manually-driven screwdriver.

Nost relevant Drior art known to the ApPlicant Machine tools such as drills and burring tools are commonly provided with shrouds to protect the fast revolving bit from being damaged and prevent the bit from causing damage by accidental shift across the surface of the work-piece upon which the tool is being used.

A recent development is the introduction of the motor-powered screwdriver. Such a screwdriver is provided with a number of inter-changeable bits. Some of these bits are provided with shrouds to constrain a screw thereto and remove the need to hold the screw to the bit during initial insertion of the screw into the worl-piece. The shroud is csseiitially an operator safety device.

To the best of the applicant's knowledge, the use of a shroud to cover the tip of a manually-driven screwdriver has not previously been contemplated, nor has the need for such a shroud been appreciated previously.

Summarv of.the Inv~ention According to a first aspect of the present invcrltioll there is provided a shroud for a manually-driven screwdriver comprising: a rigid, substantially tubular open-ended body internally dimensioned to accommodate the tip of a screw-driver and the head of a screw such that, in use, said screw is constrained into substantial axial alignment with the screwdriver and the screw may be rotated within the shroud and driven therefrom through a first open end of the shroud, the opening of the other end of the shroud being of reduced diameter to fit closely around the shank: of the screw-driver in use; and resilient biasing means adapted to be fitted to the shank of a screwdriver to bias the shroud toward the tip of the screwdriver to initially cover the tip, in use.

According to a second aspect of the invention there is provided a screwdriver having a shroud of the first aspect of the invention fitted thereto.

Preferably the resilient biasing means is a spring adapted to extend from abutment with the handle of the screwdriver to abutment with the said other end of the shroud.

Preferably the spring abuts the handle and/or the shroud via a washer adapted to minimise transmission of friction from the end(s) of the spring to the handle and/or the shroud.

Preferably the shroud is partially or wholly trallsparent to enable the screwdriver tip to be seen, in use.

Brief Descrittion of the Dralfinçs Figure 1 is a view of an embodiment of the second aspect of the invention.

Figure 2 is a longitudinal sectional view of an embodiment of the shroud according to the first aspect of the invention.

Figure 3 is a front view of the shroud of figure 2.

Figure 4 is a rear view of the shroud of figure 2.

Descrintion of the Dreferred embodiment Referring to figure 1, a conventional screwdriver is thereshown which comprises a handle 1 moulded onto the rear end 4 of a shank 2. At the other end of the shank 2 is the head of the screwdriver with its operational tip 3. A shroud 5 embodying the second aspect of the present invention is fitted to the screwdriver covering the head thereof. The shroud 5 comprises a rigid substantially cylindrical transparent plastic body having an open front, in use, end 7 of a bore large enough to permit a screw to be fitted within the shroud 5 and driven therefrom by the tip 3 of the screwdriver. The rear end of the shroud 5 has a comparatively narrower bore opening 6 therein sized to closely fit around the shank 2 of the screwdriver.

The shroud 5 is spring-loaded, such that its front end 7 extends past the tip 3 of the screwdriver, by a spring 8 winding around the shank 2.of the screwdriver and extending from the front, in use, end of the handle 4 to the rear, in use, end of the shroud 5.

The ends of the spring 8 are each separated from the shroud 5 and the handle 4, respectively, by a washer 10, 11. These washers 10, 11 limit transmission of friction from the spring to the handle 4 and shroud 5 to minimise chafing as the screwdris er is rotated and driven axially forward through the shroud 5 further compressing the spring 8.

Any chafing between the shoulders of the screwdriver head and the rear end of the shroud 5 may be reduced or avoided by provision of a low friction annular bushing 9 lining the interior of the rear end of the shroud 5.

The spring- biased shroud 5, 8 may be fitted to a screwdriver during manufacture of the .screwdriver by sliding over the rear end 4 of the shank 2 of the screwdriver prior to fitting of the shank 2 to the handle 4. Alternatively, the spring- loaded shroud 5, 8 may be retro-fitted to the screwdriver by melting the handle and/or wrenching the shank 2 from the handle 4. A retrofit may also be performed without separating the shank 2 from the handle 4 if the shroud 5 is constructed of components which can be assembled around the screwdriver. For example, the shroud 5 may be assembled from a uniform cylindrical body and a separate twopiece annular rear end wall.

To use the screwdriver with spring-loaded shroud 5, 8 fitted thereto, the head of a screw is first inserted into the open front end 7 of the shroud 5. The slot(s) in the head of the screw are fitted over the tip 3 of the screwdriver. The shroud 5 holds the screw in axial alignment with the screwdriver. The bevelled rim of the front end 7 of the shroud 5 is pressed against the workpiece. Where the work-piece is a soft wooden article, the bevelled rim to the front end 7 of the shroud 5 minimises damage to the surface of the wood. Damage to the surface of the work-piece may be further minimised by provision of a proetct?vfe%U1bbsr9raf?i:ted to the rim. As the handle of the screwdriver is turned and pressed toward the work-piece, the front end 7 of the shroud 5 remains pressed against the work-piece by the action of the spring 8, whilst the tip of the screwdriver 3 advances in a helical motion through the shroud 5 to drive the screw into place. Stable positioning of the shroud 5 relative to the work-piece enables the screw to be driven directly into place without skewing off course.

The simple construction of the spring-biased shroud 5, 8 minimises production costs, and the preferred arrangement, whereby the spring extends between the shroud 5 and the handle 4 of the screwdriver enables the screwdriver to be driven a substantial distance out from the front end 7 of the shroud 5. This latter screwdriver enables the screwdriver to be driven a substantial distance out from the front end 7 of the shroud 5. This latter ability may be of particular value for driving home a screw which is to be counter-sunk.

Claims

CLAIMS:

1. A shroud for a manually-driven screwdriver which comprises: a rigid, substantially tubular open-ended body internally dimensioned to accommodate the tip of a screwdriver and the head of a screw such that, in use, said screw is constrained into substantial axial alignment with the screwdriver and the screw may be rotated within the shroud and driven therefrom through a first open end of the shroud, the opening of the other end of the shroud being of reduced diameter to fit closely around the shank of the screwdriver in use; and resilient biasing means adapted to be fitted to the shank of a screwdriver to bias the shroud toward the tip of the screwdriver to initially cover the tip, in use.

2. A shroud according to Claim 1 wherein the resilient biasing means is a spring adapted to extend from abutment with the handle of the screwdriver to abutment with the said other end of the shroud.

3. A shroud according to Claim 2 wherein the spring abuts the handle via a washer adapted to minimise transmission of friction from the end of the spring to the handle

4. A shroud according to Claim 2 or 3 wherein the spring abuts the shroud via a washer adapted to minimise transmission of friction from the end of the spring to the shroud.

5. A shroud according to any preceding claim further characterised in that the shroud is partially or wholly transparent such as to enable the screwdriver tip to be seen, in use.

6. A screwdriver having a shroud according to any of the preceding claims fitted thereto.