GB2131113A

GB2131113A - Bolt driving formation

Info

Publication number: GB2131113A
Application number: GB08233667A
Authority: GB
Inventors: Chung-Hsing Chang
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-11-25
Filing date: 1982-11-25
Publication date: 1984-06-13

Abstract

In a bolt (10) haying a threaded stem portion (11) and a hexagonally shaped head (12), the head is provided, substantially at the center of the top surface thereof, with a recess (121) which conforms to the shape of the head (12) and which has its sides arranged parallelly to the corresponding sides of the head. This arrangement, when used with a suitable tool (Fig. 3, not shown) allows better torque transmission through the existence of more points of contact between bolt head and wrench. <IMAGE>

Description

SPECIFICATION Improved bolt construction This invention relates to a bolt of improved construction that can be efficiently turned by a socket wrench.

The conventional bolt typically has a head of flat face and multisided edges, generally six sided edges. When turning such bolt by a socket wrench, the socket is sleeved onto the bolt with its six-sided inner walls being in contact with the sides of the bolt head to transmit the applied torque to the bolt. As there are only six engaging sides at most between the socket and the bolt head, it is, sometimes, not sufficient to grip the bolt for turning, thus causing the slipping of the bolt as well as the spoilage to the bolt head.

Additionally the hexagonal head wrench generally has a L-shaped lever of certain length whereby the arm of the force for turning is usually limited. It is not ideal to turn the conventional bolt with such socket wrench when greater torque is necessary to put on or take off the bolt. It is desirable to obtain a bolt of improved construction to be well operated by a socket wrench.

It is an object of the invention to provide a bolt which can be efficiently turned by a socket wrench.

It is another object of the invention to provide an improved type of bolt that can provide more engaging surfaces with the socket to transmit the applied torque therethrough.

According to the present invention, a bolt having a threaded stem portion and polygonally shaped head is characterized in that the head is provided with, substantially at the center of the top surface thereof, a recess which conforms to the shape of the head and has its sides arranged parallel to the corresponding sides of the head.

Advantageously, the bolt is constructed in such a manner that it has a hexagonal head and a hexagonal recess.

These and other objects, features and advantages of the present invention will be more apparent in the following description of a preferred embodiment with reference to the accompanying drawings, in which: Figure 1 is a perspective view of an improved bolt constructed according to the present invention; Figure 2 is a section view of the bolt constructed according to the present invention; and Figure 3 is a section view illustrating the engagement of a bolt with a socket according to the invention.

Referring to Figs. 1 and 2 a bolt 10 according to the invention comprises, a threaded stem portion 11 and a hexagonal head 1 2.

The hexagonal head 1 2 is provided with a hexagonally shaped recess 1 21 of predetermined dimensions which has its six sides parallel to the corresponding sides of the head 12.

As shown in Fig. 3, there is shown a socket 20 which is provided with an accessory 30 which is specially designed for use in turning the bolt 10. The accessory 30 has a hexagonal head 31 adapted to fit in the hexagonal slot 21 of the socket 20. The head 31 of the accessory 30 is provided with two springloaded balls 33 retractably projected from two opposite sides thereof to engage with the inner walls of the socket 20, the accessory 30 thereby being secured in the socket 20. The accessory 30 further has a stem portion 32 which has a cross section of hexagonal shape adapted to fit in the recess 121 of the bolt 10.

When turning the bolt 10, the socket 20 is sleeved onto the bolt head 1 2 and the stem portion 32 of the accessory 30 is fitly inserted in the recess 121, the six sides inner walls of the socket 20 and the stem portion 32 being respectively engaged with six sided edge faces of the bolt head 21 and the six sided walls of the recess 1 21 to transmit the torque. It can be appreciated that the effect of the torque applied to the socket wrench is increased due to the efficient transmission of the forces through the twelve engaging faces of the socket 20 and the bolt 10.

With the invention thus expiained, it is apparent that obvious modifications and variations can be made without departing from the scope of the invention. It is therefore intended that the invention be limited only as indicated in the appended claims.

1. A bolt having a threaded stem portion and a polygonally shaped head characterized in that said head is provided with, substantially at the center of the top surface thereof, a recess which conforms to the shape of said head and has its sides arranged parallel to the corresponding sides of said head.

2. A bolt as claimed in Claim 1, in which the bolt is of hexagonal head wherein said recess is in the shape of a hexagon.

3. A bolt substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improved bolt construction This invention relates to a bolt of improved construction that can be efficiently turned by a socket wrench. The conventional bolt typically has a head of flat face and multisided edges, generally six sided edges. When turning such bolt by a socket wrench, the socket is sleeved onto the bolt with its six-sided inner walls being in contact with the sides of the bolt head to transmit the applied torque to the bolt. As there are only six engaging sides at most between the socket and the bolt head, it is, sometimes, not sufficient to grip the bolt for turning, thus causing the slipping of the bolt as well as the spoilage to the bolt head. Additionally the hexagonal head wrench generally has a L-shaped lever of certain length whereby the arm of the force for turning is usually limited. It is not ideal to turn the conventional bolt with such socket wrench when greater torque is necessary to put on or take off the bolt. It is desirable to obtain a bolt of improved construction to be well operated by a socket wrench. It is an object of the invention to provide a bolt which can be efficiently turned by a socket wrench. It is another object of the invention to provide an improved type of bolt that can provide more engaging surfaces with the socket to transmit the applied torque therethrough. According to the present invention, a bolt having a threaded stem portion and polygonally shaped head is characterized in that the head is provided with, substantially at the center of the top surface thereof, a recess which conforms to the shape of the head and has its sides arranged parallel to the corresponding sides of the head. Advantageously, the bolt is constructed in such a manner that it has a hexagonal head and a hexagonal recess. These and other objects, features and advantages of the present invention will be more apparent in the following description of a preferred embodiment with reference to the accompanying drawings, in which: Figure 1 is a perspective view of an improved bolt constructed according to the present invention; Figure 2 is a section view of the bolt constructed according to the present invention; and Figure 3 is a section view illustrating the engagement of a bolt with a socket according to the invention. Referring to Figs. 1 and 2 a bolt 10 according to the invention comprises, a threaded stem portion 11 and a hexagonal head 1 2. The hexagonal head 1 2 is provided with a hexagonally shaped recess 1 21 of predetermined dimensions which has its six sides parallel to the corresponding sides of the head 12. As shown in Fig. 3, there is shown a socket 20 which is provided with an accessory 30 which is specially designed for use in turning the bolt 10. The accessory 30 has a hexagonal head 31 adapted to fit in the hexagonal slot 21 of the socket 20. The head 31 of the accessory 30 is provided with two springloaded balls 33 retractably projected from two opposite sides thereof to engage with the inner walls of the socket 20, the accessory 30 thereby being secured in the socket 20. The accessory 30 further has a stem portion 32 which has a cross section of hexagonal shape adapted to fit in the recess 121 of the bolt 10. When turning the bolt 10, the socket 20 is sleeved onto the bolt head 1 2 and the stem portion 32 of the accessory 30 is fitly inserted in the recess 121, the six sides inner walls of the socket 20 and the stem portion 32 being respectively engaged with six sided edge faces of the bolt head 21 and the six sided walls of the recess 1 21 to transmit the torque. It can be appreciated that the effect of the torque applied to the socket wrench is increased due to the efficient transmission of the forces through the twelve engaging faces of the socket 20 and the bolt 10. With the invention thus expiained, it is apparent that obvious modifications and variations can be made without departing from the scope of the invention. It is therefore intended that the invention be limited only as indicated in the appended claims. CLAIMS