GB2356028A

GB2356028A - Threaded fasteners

Info

Publication number: GB2356028A
Application number: GB0026973A
Authority: GB
Inventors: John Jay
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-11-05
Filing date: 2000-11-06
Publication date: 2001-05-09
Also published as: GB9926193D0; GB0026973D0

Abstract

A threaded fastener includes a shank (11) which is threaded for part of its length, with a head (10) at one end of the shank (11) and a spike at the other end of the shank (11).

Description

1 2356028 THREADED FASTENERS

FieldoftheInvention

This invention relates to threaded fasteners.

Backaround to the Invention

The traditional woodscrew is normally threaded for substantially the whole of its length with the result that driving it home by hand is unnecessarily laborious and time-consuming.

It is accordingly an object of the present invention to provide an improved form of threaded fastener.

SummaryoftheInvenfion

According to the present invention there is provided a threaded fastener having a shank which is threaded for part of its length, with a head at one end of the shank and a spike at the other end of the shank..

The fastener is preferably a steel woodscrew, particularly a hardened steel woodscrew, and the length of the spike is preferably not less than 15% of the length of the shank. In a preferred embodiment, the length of the spike is between 25 and 45% of the 2 length of the shank, for example, 35% of the length of the shank, but may have a length which is over 50% of the length of the shank.

The spike may be unthreaded throughout its length but, for some applications, that part of the spike remote from the end proper of the shank may be threaded. The thread formation of such threaded part of the spike preferably merges into the thread formation of the main body portion of the shank. If the part of the spike remote from the end proper of the shank is threaded, the unthreaded part of the spike preferably has a length which is at least 15% of the length of the shank.

The shank of the woodscrew thus preferably comprises a main body portion of uniform diameter which extends from the head of the fastener for, at most, 85% of the length of the shank, and a spike. The thread formation may extend for all or part of the length of the main body portion of the shank. The thread formation may terminate short of the head of the woodscrew. It may also terminate short of the spike.

Brief Description of the Drawings

Figure I is a side view of a first form of woodscrew, Figure 2 is a side view of a second form of woodscrew, Figure 3 comprises side views of five further screw configurations, 3 Figure 4 comprises side views of another five screw configurations, and Figure 5 comprises side views of a five more screw configurations.

Description of the Preferred Embodiments

Figures 1 and 2 show typical countersunk head hardened steel woodscrews in accordance with the present invention. Each of the woodscrews comprises a head 10 and a shank 11. Each shank 11 has a length "L" and comprises a main body portion which is of uniform diameter throughout its length and a spike. The main body portion of the shank 11 comprises a first part (adjacent the head 10) which is unthreaded and has a length "a" and a second part which is threaded and has a length "b". The spike has a length "c'.

Figures 1 and 2 show shanks of preferred configurations and "a" and V are each approximately 35% of "U, while "b" is 30% of L. The heads 10 are of typical countersunk configuration, though other head configurations can be used, for example, domed head configurations and cheese-heads.

When joining two or more materials together, what is most important is secured anchoring, achieved as speedily as possible. Thus, when using the woodscrews shown in Figures 1 and 2, they are placed in position and then hammered in place, for part of the 4 length of the shank, i.e. in just the same way that a nail is hammered in place. Then, once enough purchase is achieved, and the threaded section of the shank 11 has begun to enter the surface of the material, the woodscrew is driven home by means of a screwdriver. There is thus no requirement for any pilot hole drilling and no need to use a bradawl. The resultant saving of time and effort thus gives the woodscrew of the present invention a definite advantage over other hand-driven fastenings or fixings.

Figures 3 a), b), c), d) and e) show woodscrew configurations in which the threaded portion 12 of the shank 11 has a length which is less than 20% of the total length of the shank 11. In Figure 3 a), the threaded portion 12 is adjacent the head 10 and the spike forms over 80% of the total length of the shank 11.

In Figure 3 b), the threaded portion 12 is spaced from the head 10 and is afforded partly by the lower part of the uniform diameter part of the shank 11 and partly by the spike, which has a length in excess of 75% of the total length of the shank 11.

In Figure 3 c), the spike has a length which is approximately 60% of the total length of the shank 11 and the threaded portion 12 is afforded by the lower part of the uniform diameter part of the shank 11. In Figure 3 d), the spike again has a length which is approximately 60% of the total length of the shank 11, and the threaded portion 12 is afforded partly by the lower part of the uniform diameter part of the shank 11 and partly by the spike.

In Figure 3 e) the spike has a length which is approximately 50% of the total length of the shank 11, and the threaded portion 12 is afforded partly by the lower part of the uniform diameter part of the shank 11 and partly by the spike.

Turning next to Figure 4 a), this shows a woodscrew configuration in which the spike has a length which is approximately a third of the length of the shank 11, while the thread formation extends for the whole of the length of the uniform diameter part of the shank 11 and for part of the length of the spike. Figures 4 b), 4 c) and 4 d) show woodscrews in which the spike again has a length which is approximately a third, e.g. 35%, of the length of the shank and the thread formations are at different positions along the shank, the thread formation of Figure 4 d) terminating at a position which is spaced from the end of the spike by a distance equal to approximately 20% of the length of the shank.

Figure 4 e) shows a woodscrew in which the thread formation extends for approximately 80% of the length of the shank, but in which the uniform diameter portion of the shank extends from the head 10 only for a distance of approximately 20% of the length of the shank, i.e. 60% of the length of the shank is afforded by a tapering threaded part of the shank.

Figures 5 a), b), c), d) and e) show a variety of woodscrew configurations in which the length of the spike is approximately 40% of the total length of the shank, and in which the threaded portion 12 is of different lengths and in different positions.

6 The head 10 of the screw can, as mentioned above, be of different configurations and may be formed with any appropriate slot or recess configuration for reception of a screwdriver bit. For example, it may have a simple slot, or a recess. If a recess-headed screw is used, an anvil may be provided having one end formation for fitment in the recess and the other end formation serving as an anvil to which the hammer impacts are applied. The end formation of the anvil for fitment in the recess may incorporate a magnet, to assist in holding a screw in engagement with the anvil.

The invention thus provides a threaded fastener (woodscrew) which can be driven speedily and accurately into position using only hand tools.

7

Claims

Claims:-

1. A threaded fastener having a shank which is threaded for part of its length, with a head at one end of the shank and a spike at the other end of the shank.

2. A threaded fastener as claimed in Claim 1, in which the length of the spike is not less than 15% of the length of the shank.

3. A threaded fastener as claimed in Claim 1, in which the length of the spike is between 25 and 45% of the length of the shank.

4. A threaded fastener as claimed in Claim 3, in which the length of the spike is 45% of the length of the shank.

5. A threaded fastener as claimed in Claim 2, in which the length of the spike is over 50% of the length of the shank.

6. A threaded fastener as claimed in any one of the preceding claims, in which the spike is unthreaded throughout its length.

7. A threaded fastener as claimed in any one of Claims 1 to 5, in which that part of the spike remote from the end proper of the shank is threaded.

8 8. A threaded fastener as claimed in Claim 7, in which the thread formation of the threaded part of the spike merges into the thread formation of the main body portion of the shank.

9. A threaded fastener as claimed in Claim 8, in which the unthreaded part of the spike has a length which is at least 15% of the length of the shank.

10. A woodscrew having a head and a shank which comprises a main body portion of uniform diameter which extends from the head for at most 85% of the length of the shank, and a spike.

11. A woodscrew as claimed in Claim 10, having a thread formation which extends for all of the main body portion of the shank.

12. A woodscrew as claimed in Claim 10, having a thread formation which extends for part of the main body portion of the shank.

13. A woodscrew as claimed in Claim 12, in which the thread formation terminates short of the head.

14. A woodscrew as claimed in Claim 12, in which the thread formation terminates short of the spike.

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15. A threaded fastener substantially as hereinbefore described with reference to and as shown in any one of the Figures of the accompanying drawings.