GB2584115A

GB2584115A - Screwdriver bit

Info

Publication number: GB2584115A
Application number: GB1907187.7A
Authority: GB
Inventors: John Maxwell Ogilvie Philip
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-05-21
Filing date: 2019-05-21
Publication date: 2020-11-25
Also published as: GB201907187D0; GB2584115A8

Abstract

A bit 1 for a screwdriver comprises a secondary bit component 5 coupled to a primary bit component 3 for engaging with a screw head, the primary and secondary bit components 3, 5 being moveable relative to one another, the primary bit component 3 comprising a plurality of screw head engaging members 9, 11 that are moveably coupled to one another, each comprising distal regions such as blades 15, 17 remote from the secondary bit component 5 that are configured to mate with part of a screw head, such that movement of the secondary bit component 5 towards the primary bit component 3 urges at least one of said screw head engaging members 9, 11 to move relative to the other to increase a distance between their respective distal regions 15, 17. The secondary bit component 5 may include a plunger 45 and a ramp 47 to engage with a lateral wall 37 of one of the screw head engaging members 9, 11. The bit may take several forms such as a flat blade, a Hex wrench, square bit (fig. 8).

Description

SCREWDRIVER BIT

Field

This invention relates to screwdriver bits. In one envisaged implementation of the teachings of the invention, a bit is disclosed which is configured for use with an electrical drill. In another envisaged implementation of the teachings of the invention, a bit is disclosed which is an integral component of a screwdriver (manual or powered). In the following detailed description of the teachings of the invention, particular reference is made to a screwdriver bit that is configured for use with a slotted head screw. It should be remembered, however, that this is merely illustrative of the teachings of the invention, and hence that the scope of the present invention is not limited solely to bits for use with slotted head screws.

Background

Although it is the case that there are many different types of screws in use, the most common types of screw, particularly in a domestic environment, are the so-called PhillipsTM screw and slotted head screw (also known as a slotted screw). Slotted head screws, in particular, tend to be cheap and easy to make, and are often used in applications that require the screws to be turned by hand -such as cabinetry and furniture making, for example.

Slotted head screws come in a variety of different sizes, with differing lengths of thread, differing diameter heads and differently sized slots. A variety of flat head screwdrivers are available for use with slotted head screws, each screwdriver tending to be best suited for use with a particular size of slotted head screw. As a consequence, it is usual for toolboxes to include a number of differently sized flat head screwdrivers.

It is important, in order to avoid damaging a given slotted head screw, to use a flat head screwdriver that is appropriately sized for that screw. Unfortunately, however, it is not uncommon for users to be without the particular screwdriver that would be suitable for that screw, and in such instances it has been known for users to attempt to use a screwdriver that is too small for the screw in question. In such circumstances, when the blade of the screwdriver is inserted in the slot and the user attempts to turn the screwdriver, the blade rotates in the slot until the outermost opposite edges of the blade contact opposite walls of the slot, thereby creating a pair of point contacts between the blade of the screwdriver and the walls of the slot. When the user then applies a rotational force to the screwdriver (for example to drive the screw into a block of wood), the force on the screw at these point contacts is larger than the force that would have been applied to the screw were the entirety of the screwdriver blade to have been in contact with opposite walls of the slot. This increased force can damage the screw, or even cause the screwdriver blade to fracture.

Issues concerning a lack of access to the correctly sized screwdriver for a given screw can also affect screws with other types of screwhead, such as the aforementioned PhillipsTM screw, as well as screws with Tri-angle, Robertson or Hex (Allen) sockets. Aspects of the present invention have been devised with the foregoing in mind.

Summary

In accordance with a presently preferred embodiment of the present invention, there is provided a bit for a screwdriver comprising: a primary bit component for engaging with a screw head; and a secondary bit component coupled to the primary bit component, the primary and secondary bit components being moveable relative to one another; wherein said primary bit component comprises a plurality of screw head engaging members that are moveably coupled to one another, said screw head engaging members each comprising distal regions remote from said secondary bit component that are configured to mate with a respective part of a complementary screw head with which the bit can be used, the arrangement being such that movement of said secondary bit component towards said primary bit component urges at least one of said screw head engaging members to move relative to at least one other of said screw head engaging members to increase a distance between their respective distal regions.

The bit may further comprise a resilient member operable to urge said screw head engaging members to reduce the distance between their respective distal regions.

In one embodiment the secondary bit component may comprise a plunger, movement of said secondary bit component towards said primary bit component causing said plunger to urge at least one of said screw head engaging members to move relative to at least one other of said screw head engaging members to increase the distance between their respective distal regions.

The secondary bit component may comprise an internal chamber opening distally within which said plunger is provided. The plunger may extend distally from an internal wall within said chamber. Preferably at least one surface of said plunger comprises a ramp.

In one embodiment the bit comprises first and second screw head engaging members. In this embodiment, distal regions of said first and second screw head engaging members may each include a blade. Preferably said first and second screw head engaging members are coupled together in such a way that the blade of said first screw head engaging member is substantially parallel to the blade of said second screw head engaging member.

In other embodiments said plurality of screw head engaging members may cooperate to provide a bit selected from: (i) a Hex or Allen wrench, (ii) a square or RobertsonTM bit, (iii) a PhillipsTM or FrearsonTM bit, and (iv) a TorxTM bit.

In one implementation, a proximal region of said secondary bit component may include a socket into which a connecting member can be inserted, said connecting member being configured for coupling to an electrical drill.

Another embodiment of the present invention comprises a screwdriver comprising a bit as described herein.

Other features, advantages and aspects of the present invention will be apparent from the following detailed description.

Brief Description of the Drawings

Various aspects of the teachings of the present invention, and arrangements embodying those teachings, will hereafter be described by way of illustrative example with reference to the accompanying drawings, in which: Fig. 1 is an illustrative isometric view of a bit for a screwdriver in a closed configuration; Fig. 2 is an exploded isometric view of the bit depicted in Fig. 1; Figs. 3 and 4 are cross-sectional views of the bit along the lines A-A and B-B respectively; Fig. 5 is an illustrative isometric view of the bit depicted in Fig. 1 in an open configuration; Figs. 6 and 7 are cross-sectional views of the bit depicted in Fig. 5 along the lines A-A and B-B respectively; and Figs. 8(a) to 8(d) are schematic representations of alternative bit configurations.

Detailed Description

Referring now to Fig. 1, there is depicted a schematic isometric view of a screwdriver bit 1 that implements the teachings of the present invention. In this particular illustrative example, the bit 1 is shown as being temporarily coupled to a hexagonal rod of the type that can be inserted into the chuck of an electric drill (or indeed into the chuck of an electric screwdriver), but it will be appreciated and should be noted that this is merely illustrative of the teachings of the invention. The bit could readily be temporarily or permanently coupled to a rod that has a handle formed around it for use as a manual screwdriver, and as a consequence the scope of the present invention should be construed accordingly.

With the above proviso in mind, in this particular embodiment the bit 1 comprises a primary bit component 3 for engaging with a screw head, and a secondary bit component 5 that is coupled to the primary bit component 3 so that the primary and secondary bit components can move axially relative to one another.

In this particular example the primary bit component is configured for use with a slotted head screw, but other configurations (some of which are described later) are envisaged. Similarly, in this instance, a proximal portion of the secondary bit component 5 is configured to detachably couple with a hexagonal drive rod 7 of the type that can be fitted into the chuck of an electric drill, but the secondary bit component could instead comprise a rod around which a handle is fitted to form a manually operable screwdriver. The proximal portion of the secondary bit component 5 could also be configured to couple with other shapes of drive rod (for example, a star, triangular or square shaped drive rod).

Referring now to Figs 1 and 2, the primary bit component 3 in this particular example comprises first and second screw head engaging members 9, 11 that are moveably coupled to one another. The first and second screw head engaging members each include a distal region 13 remote from said secondary bit component 5 that are configured to mate with a respective part of a complementary screw head with which the bit can be used. In this particular example the distal regions 13 of the first and second screw head engaging members 9, 11 are configured for use with a slotted screw, and to that end are tapered to form respective blades 15, 17 that are at least substantially parallel to one another. In effect, the blades 15, 17 are each one half of a conventional flat bladed screwdriver.

In this embodiment, a proximal region 19 of the first screw head engaging member 9 comprises a slot 21 into which a complementary proximal region 23 of the second screw head engaging member 11 can be inserted. The proximal and distal regions 23, 13 of the second screw head engaging member 11 meet at a generally circular portion 25 that includes a central bore 27. The first screw head engaging member is provided with a pair of aligned apertures 29 (only one of which is visible in Fig. 2) through opposite walls of the slot in the proximal region 19, and the first and second screw head engaging member can be pivotally coupled together by means of a pin 31 inserted through one of said apertures 29, through the central bore 27, and through the other of said apertures (not visible in Fig. 2).

In a preferred implementation of the teachings of the invention, a resilient member 33 is provided between the first and second screw head engaging members 9, 11, the resilient member 33 being configured to tend to draw the distal portions 13 of the first and second screw head engaging members 9, 11 together when they are urged apart. This arrangement is advantageous as it assists with decoupling the bit 1 from a screw head once the screw head has been fully screwed into a given item. The resilient force exerted by the resilient member 33 also keep the primary bit component 3 coupled to the secondary bit component 5.

As can best be seen in Fig. 3 (which figure depicts a cross-sectional view along the line A-A of Fig. 2), the proximal region 23 of the second screw head engaging member is defined by lateral walls 35, 37 that are inclined towards one another so that proximal region 23 assumes the form of a square-or rectangular-section truncated cone. Referring again to Fig. 3, and additionally to Fig. 4 (which figure depicts a cross-sectional view along the line B-B of Fig. 2), the secondary bit component 5 includes an internal wall 39 that sub-divides the secondary bit into a proximal portion (shown mated with a hexagonal drive rod 7) and a distal portion 41.

As shown in Figs. 3 and 4, the distal portion 41 includes a cavity 43, opening distally, within which a plunger 45 is provided extending distally from the internal wall 39. The plunger comprises lateral walls 47 and 49 that are set at an angle to one another, so that at least one wall of the plunger is inclined relative to the other (in this instance, wall 47 is inclined relative to wall 49). In a preferred implementation, one wall 49 extends generally perpendicularly from the internal wall 39, and the other wall 47 is inclined towards that one wall 49. Preferably the angle of inclination of lateral wall 47 is similar to that of wall 37 (relative to wall 35) when wall 35 is parallel to the walls of the distal portion 41 that define the cavity 43 (i.e. when wall 35 is in the position shown in Fig. 6).

In the arrangement shown in Figs. 3 and 4, the bit is in a rest position with the respective blades 15, 17 of the first and second screw head engaging members 9, 11 abutting.

When an axial force is applied in direction C to the secondary bit component whilst the primary bit component is located within the slot of a screw head (for example, by means of a user leaning on an electric drill to which the bit is coupled), the secondary bit component 5 will tend to move distally towards the primary bit component 3. Concomitant therewith, the plunger 49 will tend to move distally between proximal parts of the first and second screw head engaging members 9, 11 to drive those parts apart and hence widen the gap between respective blades 15, 17 of the first and second screw head engaging members 9, 11. In practice, the plunger causes the blades to move into close abutment with the walls of the slot in the screw head in which the bit is located, and when the blades are in close abutment with the walls of the slot, the likelihood of the bit rotating in the slot when a rotational force is applied to the bit and the potential for damaging the screw head are correspondingly reduced. Advantageously, this occurs "automatically" simply by virtue of the axial force applied by the user to the drill or screwdriver handle.

Similarly, when the user relaxes the axial force, the resilient member will automatically tend to draw the blades 15, 17 together, thereby disengaging the bit from the screw head.

Fig. 5 is a schematic isometric view of the bit once the secondary bit component has moved fully towards the primary bit component illustrating the accompanying increase in spacing between the respective blades 15, 17 of the first and second screw head engaging members 9, 11. Figs. 6 and 7 are cross-sectional views of the bit along the lines C-C and D-D, respectively, of Fig. 5.

As mentioned above, Figs. 1 to 7 are illustrative representations of a flat head screwdriver bit that is configured for use with slotted screws. However, this particular implementation is not the only envisaged arrangement. Figs. 8(I) to 8(iv) are illustrative depictions (looking from the distal end of the primary bit component towards the secondary bit component) of a variety of different bit configurations which embody the general inventive concept of providing a plurality of screw head engaging members that can move relative to one another to increase the spacing between distal regions of those members (and thereby enable the bit to be used with a plurality of differently sized screw heads). Fig. 8(I) is an illustration of a Hex or Allen wrench comprising six generally kite-shaped screw engaging members. Fig. 8(ii) is a square or RobertsonTM bit that is comprised of four square-shaped screw engaging members. Fig. 8(iii) is an illustration of a PhillipsTM or FrearsonTM bit with four generally kite-shaped screw engaging members, and Fig. 80v) is a schematic illustration of a TorxTM bit with six polygonal screw engaging members.

In the arrangements depicted in Figs. 8(i) to (iv) it is envisaged that the individual screw engaging members may be coupled together by a resilient member, for example a circlip extending around the periphery of the screw head engaging members, so that the screw engaging members are urged to move to reduce the spacing between distal regions on the removal of an axial force applied to the secondary bit component. It is also envisaged that the screw head engaging members will be narrower proximally than they are distally in order to create a plurality of internal ramped surfaces. The plunger in these embodiments may comprise a rod (and could conceivably be conical) that can be moved into the proximal space between the screw engaging members, and slid along the ramped surfaces to force the distal parts of the screw engaging members apart. Other mechanical arrangements and screw head engaging member configurations will be apparent to those of ordinary skill in the art.

As mentioned above, the various embodiments described in detail herein provide advantages over conventional screwdriver bits, principally -but not exclusively -by virtue of the fact that they enable a single bit to be used with a variety of differently sized screw heads. Other advantages will be apparent to persons of ordinary skill in the art. It will be appreciated that whilst various aspects and embodiments of the present invention have heretofore been described, the scope of the present invention is not limited to the particular arrangements set out herein and instead extends to encompass all arrangements, and modifications and alterations thereto, which fall within the scope of the appended claims. For example, whilst in the embodiments described above in connection with Figs. 1 to 7 it is envisaged that only the second screw head engaging portion 13 will move, it will be apparent to persons skilled in the art that both screw head engaging members could move to increase the spacing between their respective distal portions. Similarly, whilst it is envisaged in the embodiments of Figs. 8(I) to 8(iv) that the individual screw head engaging members will fan out responsive to the application of a force in an axial direction (i.e. that all the screw head engaging members will move), it is envisaged that one or more of the screw head engaging members may be stationary and for the other screw head engaging members to move to increase the distance between their respective distal portions.

It is also envisaged that the screw head engaging members need not necessarily be discrete components that are coupled to one another. Rather, the screw head engaging members could each comprise a member extending from a common ring, the plunger being movable into the ring and against one or more of the screw head engaging members to urge the screw-head engaging members apart.

It should also be noted that whilst the accompanying claims set out particular combinations of features described herein, the scope of the present invention is not limited to the particular combinations hereafter claimed, but instead extends to encompass any combination of features herein disclosed.

Finally, it should be noted that any element in a claim that does not explicitly state "means for" performing a specified function, or "steps for" performing a specific function, is not to be interpreted as a "means" or "step" clause as specified in 35 U.S.C. Sec. 112, par. 6. In particular, the use of "step of in the claims appended hereto is not intended to invoke the provisions of 35 U.S.C. Sec. 112, par. 6.

Claims

CLAIMS1. A bit for a screwdriver comprising: a primary bit component for engaging with a screw head; and a secondary bit component coupled to the primary bit component, the primary and secondary bit components being moveable relative to one another; wherein said primary bit component comprises a plurality of screw head engaging members that are moveably coupled to one another, said screw head engaging members each comprising distal regions remote from said secondary bit component that are configured to mate with a respective part of a complementary screw head with which the bit can be used, the arrangement being such that movement of said secondary bit component towards said primary bit component urges at least one of said screw head engaging members to move relative to at least one other of said screw head engaging members to increase a distance between their respective distal regions.
2. A bit according to Claim 1, the bit comprising a resilient member operable to urge said screw head engaging members to reduce the distance between their respective distal regions.
3. A bit according to Claim 1 or 2, wherein the secondary bit component comprises a plunger, movement of said secondary bit component towards said primary bit component causing said plunger to urge at least one of said screw head engaging members to move relative to at least one other of said screw head engaging members to increase the distance between their respective distal regions.
4. A bit according to Claim 3, wherein said secondary bit component comprises an internal chamber opening distally within which said plunger is provided.
5. A bit according to Claim 4, wherein said plunger extends distally from an internal wall within said chamber.
6. A bit according to any of Claims 3 to 6, wherein at least one surface of said plunger comprises a ramp.
7. A bit according to any preceding claim, comprising first and second screw head engaging members.
8. A bit according to Claim 7, wherein distal regions of said first and second screw head engaging members each include a blade.
9. A bit according to Claim 8, wherein said first and second screw head engaging members are coupled together in such a way that the blade of said first screw head engaging member is substantially parallel to the blade of said second screw head engaging member.
10. A bit according to any of Claims 1 to 6, wherein said plurality of screw head engaging members cooperate to provide a bit selected from: (i) a Hex or Allen wrench, (ii) a square or RobertsonTM bit, (iii) a PhiIlipSTM or FrearsonTM bit, and (iv) a TorxTM bit.
11. A bit according to any preceding claim, wherein a proximal region of said secondary bit component includes a socket into which a connecting member can be inserted, said connecting member being configured for coupling to an electrical drill.
12. A screwdriver comprising a bit according to any of claims 1 to 10.