GB1593545A

GB1593545A - Bolts

Info

Publication number: GB1593545A
Application number: GB3015277A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-05-30
Filing date: 1978-05-30
Publication date: 1981-07-15

Description

(54) IMPROVEMENTS IN AND RELATING TO BOLTS (71) I, EDMUND PRICE, a British Subject of 94 Brampton Grove, Kenton Harrow, Middlesex HA3 8LF do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: The present application relates to bolts and provides a bolt which is adapted not to rotate when used to join two workpieces together.

Conventionally, bolts have a screwheaded shank which is concentric with a head and threadably receives a nut whereby two workpieces can be bolted together by locating the shank through aligned holes in the workpieces and screwing the nut onto the shank to clamp the workpieces together between the head and nut. Usually, the head is shaped to facilitate gripping by a tool to prevent rotation of the bolt whilst the nut is being tightened against the adjacent workpiece. Thus, bolts usually have a square or polygonal, especially hexagonal head, for non-rotational location in a spanner.

However, it is often inconvenient and sometimes impossible to grip the head and there is therefore a demand for a bolt which is adapted not to rotate without the need to use a tool to grip the head. There have been a number of proposals for providing such a non-rotatable bolt and the most common solutions to the problem are to provide an angular section neck, particularly a square section neck, at the head end of the shank or a flat on the head. In the former bolts, it is necessary to form or provide a complementary angular hole in one workpiece to receive the neck and in the latter bolts, it is necessary to provide a flange to abut the flat. Examples of the angular necked bolts are cup-headed coach bolts and examples of the bolts having a flat on the head are the so-called "D-headed" bolts in which a flat is provided by removal of a segment from a circular head of a bolt.It will be appreciated that both of said types of non-rotatable bolts require special provision to be made in the workpiece to receive the bolt or are limited to use with deformable material such as timber.

It is known to provide bolts in which the head is offset from the shank in order to provide a cam surface for adjusting the relative positions of the two workpieces.

Such bolts are described in, for example, UK Patent Specification Nos. 937944 and 1116517. Known offset headed bolts have not, to the best of my knowledge, been used as non-rotatable bolts to secure workpieces together in a non-adjustable manner and if so used would require a counterbore in one workpiece which is offset from the hole receiving the shank. The provision of such a counterbore would be inconvenient and would add substantially to the cost and time in preparing a workpiece to receive the bolt.

It is an object of this invention to provide a bolt which is adapted not to rotate when used to join two workpieces together but which requires merely the drilling of a single respective circular hole in each workpiece.

According to the present invention, there is provided a bolt in which a screw-threaded shank is spaced from a circular head by a circular neck which is eccentrically offset from the shank and has a smaller crosssectional dimension than the head. It will be appreciated that, if a first workpiece is drilled with a circular hole complementary to the neck and a second workpiece is drilled with a circular hole complementary to the shank, the bolt will not rotate if the two workpieces are held in fixed spatial relationship with the neck and shank received in the -respective holes. In particular, if two such sets of holes are provided at spaced locations in the workpieces with the eccentricity of the holes in each set opposed, the workpieces will be retained in said spatial relationship by the respective bolts located therethrough.

The invention provides also a method of bolting two workpieces together using a bolt in which a screw-threaded shank is spaced from a head by a circular neck which is eccentrically offset from the shank and has a smaller cross-sectional dimension than the head, which method comprises forming in a first workpiece a circular hole complementary to the neck of said bolt; forming in the second workpiece a circular hole complementary to the shank of said bolt; locating said bolt with the neck and shank thereof received in the respective holes; and screwing a nut onto the shank to clamp the workpieces between the head and the nut.

In a preferred embodiment of the method of the invention, there are provided two said sets of holes at spaced locations in the workpieces with the eccentricity of the holes in each set opposed; respective bolts of the invention are located in the respective sets and respective nuts screwed onto the shanks thereof to clamp the workpieces together between the heads and nuts.

The bolts for use in the method of the invention can have any of the head shapes used in conventional bolts, for example, square, polygonal, domed or eye-bolted, but preferably is circular and, especially, flat, i.e. disc-like. The head can be eccentric to the shank but preferably is concentric therewith.

The shank can also be of any screwthreaded kind used in conventional bolts and the thread can extend over all or only part of the shank.

Advantageously, the circular neck is spaced at all points along its circumference radially inwardly from the periphery of the head.

The bolts can be formed of any material suitable for the intended purpose of the bolt but usually will be formed of metal, especially steel. They can be formed by, for example, turning or, preferably, forging.

The following is a description, by way of example only and with reference to the accompanying drawings, of embodiments of the present invention. In the drawings: Figure 1 is an end view of a bolt in accordance with one embodiment of the invention; Figure 2 is a side elevation of the bolt of Figure 1; Figure 3 is an end view of a bolt in accordance with another and preferred embodiment of the present invention Figure 4 is a side elevation of the bolt of Figure 3; Figure 5 is a cross-sectional view showing the bolt of Figures 1 and 2 securing two workpieces together; Figure 6 is a plan view of a first workpiece to be secured to a second workpiece by bolts of Figures 3 and 4; Figure 7 is a plan view of the said second workpiece; Figure 8 is a plan view of the workpieces of Figures 6 and 7 secured together by bolts of Figures 3 and 4; and Figure 9 is a cross-section on the line AA of Figure 8.

Referring first to Figures 1 and 2, a bolt generally indicated at 1 comprises a screwthreaded shank 2 spaced from a flat circular head 3 by a circular neck 4. Both the head 3 and the neck 4 are eccentrically offset from the shank 2 but said head and neck are mutually concentric in this embodiment.

The bolt shown in Figures 3 and 4 is generally indicated at 11 and also comprises a screw-threaded shank 12 spaced from a flat circular head 13 by a circular neck 14.

However in this embodiment, which is presently preferred, only neck 14 is eccentrically offset from the shank 12; the head 13 being concentric with the shank 12, Referring now to Figure 5, a hole 5 complementary to the shank 2 of bolt I is drilled through a first workpiece 6 and a hole 7 complementary to the neck 4 of said bolt is drilled through a second workpiece 8.

The workpieces.6, 8 are moved relative to each other until the holes 5, 7 are aligned with the same degree of eccentricity as the shank 2 and neck 4. The bolt is then inserted into the holes from the workpiece 8 until the head 3 abuts the surface of the workpiece 8.

In said position, the neck 4 is recieved in hole 7 and the shank passes through hole 5.

Although Figure 5 shows the workpiece 8 having a thickness equal to the depth of the neck 4, it will be appreciated that this is not necessary and that often the thickness of the workpiece 8 will be greater than the depth -of the neck 4. The work pieces are secured together by a nut 9 screwed onto the shank 2 and tightened by a spanner or other tool onto the surface of workpiece 6 to clamp the workpieces 6, 8 together between itself and the head 3. If the relative positions of the workpieces is retained, the bolt 1 cannot rotate during tightening of the nut because of the eccentricity between the neck 4 and shank 2. It is preferred therefore that a second set of holes 51, 7' receive a second bolt 11 with its eccentricity opposed to that of bolt 1.

Figures 8 and 9 show a pair of workpieces 16, 18 clamped together by three bolts 11 and nuts 19 received thereon. The bolts 11 are received in holes 15, 17 in the workpieces 16, 18 respectively (see Figures 6 & ) in the manner described above with reference to Figure 5.

It will be appreciated that the invention is not restricted to the particular details described above but that numerous modifications and variations can be made without departing from the scope of the invention as claimed in the following

Claims

Claims. WHAT I CLAIM IS:

1. A bolt in which a screw threaded shank is spaced from a circular head by a circular neck which is eccentrically offset from the shank and has a smaller cross-sectional dimension than the head.

2. A bolt as claimed in Claim I wherein the head is flat.

3. A bolt as claimed in any one of the preceding Claims wherein the head is concentric with the shank.

4. A bolt as claimed in any one of the preceding Claims wherein the neck is spaced at all points along its circumference radially inwardly from the periphery of the head.

5. A bolt substantially as hereinbefore described with reference to and as shown in Figures 1 and 2 of the accompanying drawings.

6. A bolt substantially as hereinbefore described and as shown in Figures 3 and 4 of the accompanying drawings.

7. A method of bolting two workpieces together using a bolt in which a screwthreaded shank is spaced from a circular head by a circular neck which is eccentrically offset from the shank and has a smaller cross-sectional dimension than the head, which method comprises forming in a first workpiece a circular hole complementary to the neck of said bolt; forming in the second workpiece a circular hole complementary to the shank of said bolt; locating said bolt with the neck and shank thereof received in the respective holes; and screwing a nut onto the shank to clamp the workpieces between the head and the nut.

8. A method as claimed in Claim 7 wherein the bolt is as claimed in any one of Claims I to 6.

9. A method as claimed in Claim 7 or Claim 8 wherein two sets of said holes are provided at spaced locations in the workpieces with the eccentricity of the holes in each set opposed; respective bolts as claimed in any one of the preceding Claims are located in the sets and respective nuts screwed onto the shanks thereof to clamp the workpieces between the heads and nuts.

10. A method as claimed in Claim 7 and substantially as hereinbefore described with reference to Figure 5, or Figures 6 to 9 of the accompanying drawings.