GB2285940A

GB2285940A - Fastening system

Info

Publication number: GB2285940A
Application number: GB9401513A
Authority: GB
Inventors: Malcolm Turner
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-01-27
Filing date: 1994-01-27
Publication date: 1995-08-02
Also published as: GB9401513D0; CA2158980A1; EP0690964A1; JPH08512122A; AU1421495A; GB2285940A9; WO1995020727A1

Abstract

The terminal portion of screwdriver blade 11 has stepped portions of successively smaller dimension towards its tip for use with any of a range of screws with different dimensions where the largest of the screws will have a complementary stepped slot to be engaged by all of the portions 12, 13, 14 of the blade, smaller screws will have a slot to be engaged by the portions 12 and 13 only, and the smallest will have a recess to be engaged by the tip portion 12 only. In other embodiments (Fig. 4) the portion of the tool may be hexagonal or of other non-circular shape and again the screws are to have complementary recesses. The invention is useful with screws, bolts and other fastening pins both threaded or non-threaded of a wide range of types, and in the case of non-threaded fasteners the tool and recess cross-section need not be non-circular. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO TOOLS The present invention relates to tools and, more specifically, to tools for tensioning and un-tensioning threaded elements.

In this specification the term "threaded elements" is intended to cover bolts or screw elements, for co-operation with a nut, and elements having a spiral thread, reducing in diameter from the head of the element towards the tip, such as wood screws and wherein a thread for co-operation with the threaded element is generally cut by the element.

Bolts and screws may include a hexagonal head, engageable by a spanner and by which the threaded elements may be rotated to tension the element with, or release the element from, its co-operating internal threaded member. In other embodiments the bolt or screw may include a slotted head, whereupon the threaded element is tensioned and un-tensioned by the use of a screwdriver, and in more recent years the head of the threaded element may include an hexagonal recess, into which a hexagonal sectioned key can be engaged to tension or release the threaded element from its co-operating internal thread.

A serious problem with conventional threaded elements arises from the fact that there are a very large number of different diameter sizes of such threaded elements and, for each type of threaded element, the workman requires a plurality of tools for manipulating the differently sized threaded elements. Thus, if the threaded elements have hexagonal heads, the size of the head will vary as the diameter of the threaded element varies and a workman requires a plurality of spanners for tensioning and un-tensioning the range of threaded elements. In like manner the workman will require a plurality of differently dimensioned screwdrivers, for working different sizes of slotted threaded elements, and even for hexagonally recessed screws and the like threaded elements the workman requires a plurality of hexagonally sectioned keys to accommodate the different sizes of hexagonal recesses.

The present invention seeks to provide a tool capable of being used to tension and un-tension a wide variety of differently sized threaded elements.

According to the present invention there is provided a tool for use with threaded elements, the said tool presenting a first element aligned with, and extending from a second element, the second element having cross-sectional dimensions greater than those of the first element, the first element being arranged to engage in a recess in the head of a threaded element having a diameter which is less than a predetermined diameter, and whereby said first element when engaged in the said recess can be rotated to tension or untension the threaded element, and said first and second elements being engageable in recesses formed in the head of threaded elements above a predetermined diameter to tension and un-tension the threaded element.

Thus, with this arrangement, the threaded elements above a predetermined diameter have a first recess, for receiving the first element of the tool, and said first recess is formed in the bottom of a second recess for receiving the second element of the tool.

Preferably the tool includes a third working element and the second working element is rigidly depending from said third working element.

Preferably, all threaded elements are provided with a recess engageable by the first working element, all threaded elements above a predetermined size are provided with a recess engageable with the first and second working elements and all threaded elements above a specific size include a recess engageable by the first, second and third elements of the tool.

In one embodiment the first, second and third elements of the tool are of rectangular cross-section, whereupon the tool acts as a screwdriver.

In another embodiment the first, second and third elements of the tool are of multi-sided construction, concentric with an axis passing though the centre of area of each cross-section of said first, second and third elements.

In one preferred embodiment the cross-sections of the first, second and third elements are hexagonal.

In one embodiment in accordance with the invention the recess extends across the head of the threaded element.

In another embodiment the said recess is a multisided recess and, more preferably, the multi-sided recess is substantially concentric with the axis of the threaded element.

In a preferred form in accordance with the invention the multi-sided recess is an hexagonal recess.

The invention will now be described further by way of example with reference to the accompanying drawings in which: Fig 1 shows, in prospective view, the working end of a screwdriver-type tool in accordance with the invention.

Fig 2 shows, in plan view, a screw head arrangement for use with the tool illustrated in Fig 1.

Fig 3 shows an axial section through the head region of the screw illustrated in Fig 2, on the line II-II in Fig 2.

Fig 4 shows, in prospective view, a tool end for a hexagonal-recessed threaded element and Fig 5 shows in axial cross-section, a threaded element arrangement for use with the tool illustrated in Fig 4.

The screwdriver type tool illustrated in Fig 1 is formed on one end of a bar element 11 and the extreme end of the element 11 is shaped to define a first screwdriver element 12, a second screwdriver element 13 and a third screwdriver element 14. The element 12 has a width and thickness enterable into the slotted end of the smallest ranged of screw heads to be accommodated by the element 11, the second element 13, integral with the element 12, has a width and thickness greater than the width and thickness of the element 12, to enter into a range of screw heads larger than the screw heads to be accommodated solely by the element 12 but having a maximum diameter less than the width of the element 14, and the element 14 is of such width as to be capable of tensioning and unr tensioning the larger range of screw heads to be accommodated by the tool end 11.

Figs 2 shows a plan view of the head of a screw 15, and Fig 3 shows a cross-section of the said screw 15, and which screw 15 is of the largest in the range of threaded elements to be accommodated by the element 11. The said screw head 15 includes a first slot 16, which extends across the head of the screw head 15 and which slot 16 is to dimensioned to receive the third element 14 therein, a recess 17 in the bottom midregions of the slot 16, dimensioned to receive the second element 13 therein, and a further recess 18, in the bottom of the recess 17 and dimensioned to receive the first element 12 therein. Thus, when the element 11 is inserted into the screw head 15 the first element 12 is located in the recess 18, the second element 13 is located in the recess 17, and the third element 14 is engaged in the slot 16 of the screw 15.

With the element 11 so inserted into the screw head 15 the element 11 can be rotated to tension or un-tension the screw, having the head 15, in its co-operating thread.

For an intermediate range of screws, having heads smaller than the width of the element 14 but wider than the element 12, the recess 17 will extend across the head of the screw, to receive the element 13 therein, and the recess 18, to receive the element 12, will be set in the bottom of the transverse slot 17 in the screw head 15.

For the smaller range of threaded elements, having a head diameter smaller then the width of the recess 17, the screw head 15 will have only one slot across it's head and into which the first element 12 can enter, in identical manner to a conventional screwdriver and slotted screw.

Thus, with the above arrangement, the tool element 11 can be used with a wide range of differently dimensioned screw heads and the end of the element 11 having the elements 12, 13 and 14 formed thereon may taper towards the free end of the element 12, as illustrated, so that the elements 12, 12 and 13, or 12, 13 and 14 provide sufficient rigidity to allow all threaded elements engageable by element 11 to be rotated, to tension or un-tension the screw element.

In the tool element illustrated in Fig 4, said tool present an hexagonal cross-section and, at the free end of the tool element 20, the element 20 presents an hexagonal section 21, of smaller cross-sectional dimensions than those of the element 20, and the element 21 presents a further hexagonal section 22 of smaller cross-sectional dimensions than those of the element 21. Thus, in this form of the tool, the hexagonal end section 22 defines the first element of the tool, the hexagonal section 21 defines the second element of the tool and that part of the hexagonal form 20 immediately adjacent the element 21 defines the third element of the tool.

The tool illustrated in Fig 4 is intended for use with a screw 23 having a head 24, shown in cross-section in Fig 5. The head 24 has an hexagonal recess formed therein, the outermost parts of the recess being defined by an hexagonal recess 25, arranged to snugly receive those end regions of the element 20 adjacent hexagonal section 21, an hexagonal recess 26 formed in the base of the recess 25 and dimensioned to receive the hexagonal section 21 thereinto, and an hexagonal recess 27, dimensioned to receive the hexagonal section 22 thereinto, formed in the base of the hexagonal recess 26.

Thus, for large diameter threaded elements of the type shown in Fig 5, the end of the element 20 is inserted into the hexagonal recesses 25, 26 and 27 formed in the head 24 of the screw 23 so that, when the element 20 is rotated to tension or un-tension the screw 23, all three hexagonal sections 20, 21 and 22 engage with their respective recess 25, 26 and 27 to tension or unotension the screw element 23.

For an intermediate range of threaded elements 23, and wherein the head 24 of the threaded element 23 is of smaller diameter, the head 24 may have formed therein only the hexagonal recesses 26 and 27, to receive the hexagonal sections 21 and 22 of the tool element 20 thereinto, and when the threaded elements 23 are of the smaller diameter range the head 24 will include only 1 hexagonal recess, recess 27, to receive the hexagonal section 22 thereinto and whereupon the tool acts like a normal allan key arrangesent.

Claims

1. A system for installing and/or removing screwthreaded elements comprising the use of a tool and a selection made from a plurality of threaded elements of different sizes, in which: (a) The tool has a shaft terminating in a series of at least two axially juxtaposed portions of non circular cross-section and successively smaller dimensions normal to the axis of the shaft and approaching the free end of the shaft.

(b) The larger sizes of said threaded elements each have a stepped recess complementary in shape and size to said shaft termination.

Whereas (c) smaller sizes of said threaded elements have a stepped recess complementary in shape and size to one or more of the smaller dimension portions of said shaft termination but not including a recess portion complementary in shape and size to the largest of said non-circular portions.

2. A tool for use in a system of Claim 1 comprising a handle adapted for applying torque, and a shaft extending from said handle, said shaft being of a non-circular shape and size complementary to the shape and size of the largest recess portion of any of the plurality of threaded elements of different sizes with which the tool is to be used, said shaft terminating in two axially juxtaposed portions of similar non-circular cross-section and successively smaller dimension, and the free end face of the smallest portion being domed or pointed.

3. A screw-threaded element for use in the system of Claim 1 having at one or other or both ends a recess of non-circular shape and of an axial dimension comparable to that of the smallest of the non-circular portions provided in the end of the tool.

4. A screw-threaded element for use in the system of Claim 1 having at one or other or both axial ends a recess comprising a first portion of non-circular shape adjacent to the said end and a second and smaller recessed portion opening therefrom into the screwthreaded element, said smaller portion corresponding in shape and dimension to the smallest dimension portion of the tool termination and the larger recessed portion corresponding in shape and dimension to the next larger portion of the tool.

5. A screw-threaded element for use in the system of Claim 1 provided with a recess at one or other or both axial ends of the fastener, said recess comprising three successive portions of non-circular shape complementary to those of the shaft and termination portions of the tool and the axial dimension and shape of the two smaller recessed portions corresponding to the axial dimension and shape of the said two axially juxtaposed portions of the tool.

6. A system or a tool or an element as claimed in any preceding claim wherein the non-circular shape is hexagonal.

7. A system, a tool or a screw-threaded element as claimed in any preceding claim wherein the said portions or recess portions have substantially planar side faces which are substantially parallel to the axis of the shaft or the screw-threaded element as the case may be.