GB2342134A

GB2342134A - Screw head cap

Info

Publication number: GB2342134A
Application number: GB9921447A
Authority: GB
Inventors: Kenneth Simpson
Original assignee: Newmond Building Products Ltd
Current assignee: Newmond Building Products Ltd
Priority date: 1998-09-12
Filing date: 1999-09-13
Publication date: 2000-04-05
Also published as: GB9921447D0

Abstract

A screw head cap (1) for use with a screw (5) having a shank (4) and a head comprising a base portion (2), a top portion (7) and side walls (6). An aperture (3) extending through the base portion (2) receives the shank (4) of a screw (5) being driven into a substrate (11). An annular recess is formed between the side walls (6) intermediate the top (7) and base (2) portions. The top (7) portion comprises two or more co-operating segments (7a) extending inwardly from the side walls (6) through to the recess The head cap (1) having a first substantially inverted cone shaped condition wherein the segments (7a) in the top portion (7) provide an opening having an axis concentric with the aperture (3) in the base portion (2) and a second substantially cylindrical shaped condition wherein the screw (5) is received in the recess.

Description

2342134 SCREW HEAD CAP The present invention relates to plastic screw head

caps used to conceal 5 metallic screw heads particularly in external roofline work.

It is known to conceal metallic screw heads by using caps made from a plastics material. Known screw head caps generally comprise two components; firstly a collar placed around the screw shank prior to insertion of the screw into a substrate secondly a cap which is secured to the collar by means of a snap-fit engagement after insertion of the screw into the substrate. Such known caps often become disengaged from the collar and are lost, furthermore there is a need to carry and fit two components.

The object of the present invention is therefore to provide a single component screw head cap which can be fitted to the shank of the screw before sale if required and does not become disengaged from the screw head.

According to a first aspect the present invention provides a screw head cap for use with a screw having a shank and a head secured thereto, the screw head cap comprising a base portion, a top portion and side walls, an aperture extending through the base portion to receive the shank of a screw when the screw is required to be driven into a substrate, an annular recess formed between the side walls intermediate the base and top portions, and extending outwardly from the said aperture, the top portion comprising two or more co-operating segments formed by slots extending inwardly from the side walls through to the said recess, the head cap having a first substantially inverted cone shaped condition, in which the 2 segments in the top portion provide an opening having an axis concentric with the aperture in the base portion and a second substantially cylindrical shaped condition in which the screw head is received in the recess, movement from the first to the second condition resulting from the screw being driven into the substrate thereby forcing the screw head through the opening formed by the segments making up the top portion and against the base portion forcing the head cap to assume the second substantially cylindrically shaped condition and to thereby conceal the screw head when the screw is driven home and provide a seal between the screw head and 10 the substrate.

Preferably the base and top portion of the head cap are at right angles to the side walls.

The provision of a one component screw head cap avoids the possibility of the cap becoming dislodged and lost and avoids the need to carry and fit two components. The screw head cap of the present invention is easy to fit as it covers the screw head during insertion of the screw into the substrate, no separate fitting is required.

Preferably the top portion comprises four segments extending inwardly from the side wall each comprising a quarter of a circle segment. The use of four segments provides a substantially circular opening therebetween when the cap is in the first condition.

The screw head cap of the present invention may be moulded onto the screw shank or alternatively preassembled on to the screw shank before sale or use which saves time on-site.

3 Preferably the screw head cap is made from a resiliently flexible plastics material. The screw head cap is preferably formed by injection moulding most preferably multicavity injection moulding.

The base portion may be substantially continuous or alternatively the base portion may be formed from one or more discrete portions. Preferably the base portion is provided with extensions thereof which lie parallel to the substrate when the cap is in the first condition. In use the screw head preferably contacts such extensions of the base portion on insertion into a 10 substrate. Pressure applied to the base portion and/or the extension thereof moves the screw head cap from the first condition to the second condition.

The present invention will now be described by means of example only with reference to the figures in which:- Figure 1 shows a top view of a screw head cap of the present invention in the first condition; 20 Figure 2 shows a cross section view of the screw head cap of figure 1 in use with the screw partially driven into a substrate; Figure 3 shows a top view of the screw head cap of the present invention in the second condition; and 25 Figure 4 shows a cross section view of the screw head cap of figure 3 in use with the screw fully driven into the substrate.

The screw cap 1 of the present invention comprises a circular base portion 2 having an aperture 3 therein for receipt of the shank 4 of a 4 screw 5, side walls 6, and a top portion 7. An annular recess 12 is formed between the side walls 6 intermediate the base 2 and top 7 portions. The annular recess 12 extends outwardly from the aperture 3 in the base portion 2.

The top portion 7 comprises four segments 7a (see figure 1) formed by providing slots 7b extending inwardly from the side walls 6 through to the said recess 12. The base portion 2 and top portion 7 lie at right angles to the side walls 6.

The head cap 1 has a first substantially inverted frustoconical shaped condition shown in Figures 1 and 2 wherein the side walls 6 extend outwardly from the base portion 2. In the first condition the segments 7a provide an opening having an axis concentric with the aper-ture 3 in the base portion. The opening between the segments 7a is sufficient for the head 8 of screw 5 to pass through.

The base portion 2 has an extension 10 which lies parallel to the substrate 11 when the cap 1 is in the first condition. The nail head 8 contacts and applies pressure to the extension 10 of base portion 2 as it enters the substrate 11.

The head cap 1 has a second condition shown in Figures 3 and 4 wherein like numbers designate like parts and the side wall 6 extends upwardly from the base portion 2 substantially at right angles thereto and the cap 1 adopts a substantially cylindrical shape.

The four inwardly extending segments 7 form a substantially planar surface covering the nail head 8 and the base portion 2 lies parallel to the substrate 11 and the extension 10 surrounds the nail head 8.

In use the screw head cap 1 can be premoulded to the shank 4 during manufacture or can be assembled to the screw shank 4 before sale or use. The cap 1 is assembled to the screw shank 4 in the first condition.

In use the screw shank 4 is inserted into a substrate 11 by use of a screw driver (not shown). The screw head 8 passes between the inwardly extending segments 7 to contact the extension 10 of the base portion 2. Downward pressure applied to the extensions 10 by the screw head 8 as the screw shank 4 is driven into the substrate 11 forces the extension 10 toward the substrate 11 which in turn moves the cap 1 from the first condition to the second condition. The inwardly extending segments 7a contact the shaft of the screwdriver on moving to the second condition and compress until the screwdriver is removed when they expand to form a substantially planar surface covering the screw head 8.

Claims

6 CLAIMS

I A screw head cap for use with a screw having a shank and a head secured thereto, the screw head cap comprising a base portion, a top portion and side walls extending between the base and top portion, an aperture extending through the base portion to receive the shank of a screw when the screw is required to be driven into a substrate, an annular recess formed between the side walls intermediate the base and top portions and communicating with the said apertur, the top por-tion comprising two or more segments formed by slots extending inwardly from the side walls through to the said recess, the head cap having a first substantially inverted cone shaped condition, in which the segments in the top portion provide an opening having an axis concentric with the aperture in the base portion and a second substantially cylindrical shaped condition in which the screw head is received in the recess, movement from the first to the second condition resulting from the screw being driven into the substrate thereby forcing the screw head through the opening formed by the segments making up the top portion and against the base portion forcing the head cap to assume the second substantially cylindrically shaped condition and to thereby conceal the screw head when the screw is driven home and provide a seal between the screw head and the substrate.
2. A screw head cap according to claim I wherein the base and top portions of the head cap are at right angles to the side walls.
3. A screw head cap according to claim I or claim 2 wherein the top portion comprises four segments extending inwardly from the side walls each comprising substantially a quarter a of a circle segment.

7
4. A screw head cap according to any preceding claim wherein the screw head cap is moulded onto the screw shank.
5. A screw head cap according to any one of claims I - 3 wherein the screw head cap is preassembled on to the screw shank before sale or use.
6. A screw head cap according to any preceding claim wherein the base portion is substantially continuous.
7. A screw head cap according to any one of claims I - 5 wherein the base portion is formed from one or more discrete portions.
8. A screw head cap according to any preceding claim wherein the base portion is provided with extensions thereof which lie parallel to the substrate when the cap is in the first condition.
9. A screw head cap substantially as described herein and with reference to the drawings.