WO1991017873A1

WO1991017873A1 - Protection means for handsaw

Info

Publication number: WO1991017873A1
Application number: PCT/AU1991/000209
Authority: WO
Inventors: Robin Mcgarvie
Original assignee: Robin Mcgarvie
Priority date: 1990-05-23
Filing date: 1991-05-16
Publication date: 1991-11-28

Abstract

A guard protection device (46) for a handsaw (40) includes a shield (47) which is releasably attachable to the handle of the handsaw (40) by means of an upper connection means (49) and a lower connection means (48). The shield (47) is dimensioned to protect the hand of a user of the handsaw. The device (46) is removable from the handsaw when not required and may include an additional connector (52) to securely hold the device (46) in position.

Description

PROTECTION MEANS FOR HANDSAW TECHNICAL FIELD

This invention relates to a protection means for a handsaw. The invention will be particularly described with reference to a hand protector for a hacksaw, but it is to be understood that the invention has a wider application. BACKGROUND ART

Hacksaws generally comprise an inverted U-shaped frame having a saw blade connected between the free ends of the two legs of the frame. A handle of some description is formed on one side of the frame, and the handle is usually integral with and forms part of one of the legs of the frame. Hacksaws used for cutting metal are generally of reasonably robust construction and the blade is held tautly by the frame. Tensioning means is provided for adjusting the tension on the blade, and is also used for releasing tension when the blade is to be replaced.

Metal hacksaws are often used to cut metal or other material which is located in inaccessable locations. The user of the saw is then obliged to bring the saw into this location, and then work the saw back and forth in a sawing motion in order to achieve the required cut. It often happens in these situations that the user's hand inadvertently contacts or fouls against an obstruction or sharp object resulting in injury to the hand. Also, when cutting metal during the working of the metal by welding or the like the user's hand can be injured by the welding torch or hot metal. Clearly there are many such situations where injuries of the type described above can occur to users of handsaws. DISCLOSURE OF INVENTION

It is an object of this invention to provide means which can be connected to a handsaw to substantially prevent injuries to the user's hands.

According to the invention there is provided a protection device adapted to be releasably mounted to the handle of a handsaw, said device comprising a curved shield, an upper connection means on said shield for releasably connecting the device to an upper part of a said handsaw, and a lower connection means for releasably connecting the device to a lower part of the handsaw, said shield being dimensioned such that a users hand which operatively holds a handsaw to which said device is mounted will nest behind and thereby be protected by said device. BRIEF DESCRIPTION OF DRAWINGS

A protector having these features can be configured in various ways and the attached drawings depict five different embodiments of the invention suitable for attachment to commercially available hacksaws. The drawings are, however, merely illustrative of how the invention might be put into effect and the invention is accordingly not limited to what is shown.

In the drawings:

Figure 1 shows a side view of a hacksaw handle with a protector according to the invention fitted thereto; Figure 2 shows a perspective view of the handle and protector shown in Figure 1;

Figure 3 shows a side view of a hacksaw similar to that shown in Figure 1 but with a different embodiment of protector fitted thereto;

Figure 4 shows a section along line IV-IV of Figure 3;

Figure 5 shows a side view of a different embodiment of hacksaw with a different protector fitted thereto;

Figure 6 shows a side view of a further type of hacksaw with another embodiment of protector fitted thereto;

Figure 7 shows a section along line VII-VII of Figure 6.

Figure 8 shows a rear view of a yet further embodiment of protector; and

Figure 9 shows a cross-sectional side view along line IX-IX of Figure 8. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Turning initially to Figure 1, a hacksaw 1 as shown which includes a frame 2 and a handle 3. A attachment mount 4 is provided to which a hacksaw blade 5 can be connected. The handle 3 includes a socket 6 on the forward end thereof and the frame 2 locates in that socket 6 in order to connect the frame 2 to the handle 3. The frame.2 includes a plurality of trans- verse holes 7 and a thumbscrew 8 passes through a corresponding hole in the handle 3 in order to secure the frame and handle together. The handle 3 includes a hand engageable part 9 around which a user's hand will grip in order to hold the hacksaw. An opening 10 is provided forward of the hand engageable part 9 and the fingers of a users hand will pass through that opening 10 when the hacksaw is operatively gripped by the user. A post or guard 11 is located forward of the opening 10 and that post 11 serves to define the forward side of the opening 10 and further serves to rigidify the handle 9 as well as providing limited protection for a user's hand.

As shown in Figures 1 and 2 a guard or protector 12 is fitted to the hacksaw 1. The protector 12 includes a shield 13 which is wider than the width of the handle 3. The shield 13 may be of a substantially part cylindrical shape with the concave side of the shield facing towards the rear of the hacksaw. The hand of a user which is operatively holding the hacksaw will nest in the recess defined by this concave shape.

The protector is connected to the hacksaw by any suitable means. As shown in Figures 1 and 2, the shield 13 includes a U-shaped recess 14 on the operatively upper side thereof and that recess defines two arms 15 which locate on opposite sides of the handle when the protector is mounted in position. One of those arms includes a mounting hole 16 therein and the thumbscrew 8 which is used to hold the frame to the handle passes through the opening 16 in order to securely connect the protector 12 to the handle 3. In addition, the lower end of the shield 12 has a U-shaped recess 17 formed therein and that recess 17 locates around the mount 4 thereby securely locating the operatively lower side of the protector relative to the handle 3. In addition, a pair of tapered flanges 18 extend rearwardly from the lower edge of the shield 13 and the flanges 18 locate on opposite sides of handle 3 to thereby properly secure the lower edge of the protector against the handle 3. The flanges 18 also serve to protect the underside of the user's hand from objects which may in use injure the lower side of the hand.

The protector may conveniently be securely pressed against the post 11 by means of a support strut 20. That strut may conveniently be mounted to the front side of the shield 13 and extend upwardly towards the frame 2. The upper end 21 of the strut 20 has a saddle shape and the saddle shape locates underneath the frame 2, the frame 2 thereby serving to press against the strut 20 and thereby press the protector 12 against the post 11.

In use, when the blade 5 is tensioned by the tensioning means (not shown) for the hacksaw the frame 2 will distort slightly to thereby contact the strut 20 and press the protector firmly against the post 11. The protector 12 is thus held to the hacksaw by the combined effect of the thumbscrew 8 passing through the hole 16 and the frame 2 pressing against the strut 20. This combined effect will ensure that the protector is securely held in position and even if the shield 13 is knocked or jolted as the saw is being used it will remain in position and thereby serve to protect the hand of the user.

Turning now to Figure 3 of the drawings the hacksaw 1 is the same as that shown in Figures 1 and 2 but the protector 25 is somewhat different. The protector 25 includes a trough-shaped mounting portion 26 which projects forwardly of the shield from the upper edge thereof. The mounting portion 26 is more clearly shown in cross-section in Figure 4 and as shown includes a pair of arms 27 which define an open mouth 28 between them. The free ends of the arms 27 are splayed as depicted at numeral 29. The trough-shaped mounting portion is preferably made from a resilient material which will enable the protector to be clipped around the frame 2 by simply pressing the frame into the space between the arms 27. This will cause the arms to move apart to admit the frame 2 and they will thereafter resiliently move back together to hold the protector in position on the handle. The advantage of a simple clip-on arrangement is that the protector can be fitted to the hacksaw when it is needed but can be easily removed therefrom without needing firstly to dismantle the hacksaw or to release the tensioning means from the blade. The protector shown in Figures 3 and 4 will conveniently be made from a high strength mouldable plastics material such as high strength polyurethane or the like.

The shield portion 30 of the protector is similar to that depicted in Figures 1 and 2 and also serves to form a protective zone behind the protector in which the hand of a user locates.

Turning now to Figure 5, a different embodiment of the invention is shown for use on a different type of hacksaw. A hacksaw 31 is shown which has a different location of assembly screw 32 and the protector 33 is specifically adapted to fit- this particular hacksaw 31. The protector 33 includes a pair of flanges 34 which locate on opposite sides of the handle 35. The protection shield 36 is connected to the flanges 34 and stiffening ribs 37 serve to reinforce the shield to ensure that it has sufficient rigidity to serve the protective function for which it is intended. The protector 33 can be easily removed by removing the thumbscrew 32.

A yet further embodiment of protector is depicted in Figures 6 and 7 of the drawings. As shown, a hacksaw 40 includes a tensioning means 41 which is used to tension the blade 42. The tensioning means includes a lever 43 to which the blade 42 is attached and the lever 43 pivots about a pin 44 which connects the lever to the handle 45. The protector 46 which is fitted to this particular hacksaw includes a shield 47 of similar form to that depicted in the previous embodiments and includes a pair of flanges 48 on the lower edge of the shield 47 to close off the lower side of the protective zone provided by the shield. The protector 46 preferably has a resilient trough-shaped connector 49 formed integral therewith for connecting the protector 46 to the frame 50 of the hacksaw. As shown in Figure 7 the connection arrangement is also a clip-on arrangement so that the protector 46 can be easily removed when not required.

To allow for the pivoting of the lever 43 the protector 46 includes in its lower central region a cut-out region, depicted by dotted lines 51, which extends approxim- ately half way up the central portion of the shield. Above that cut-out region 51 an intermediate connector in the form of a pair of flanges 52 locate on opposite sides of the support post 53 to hold the protector in position on the handle and rigidify the connection between the protector and the handle. The clip-on connection arrangement provided by the connector

49 and the location of the flanges 52 serve to securely hold the protector 46 to the hacksaw 40.

Figures 8 and 9 depict a yet further embodiment of protector. The protector 55 shown is formed of a high strength resilient plastics material such as a PVC or nylon and is preferably formed by an injection moulding or similar technique. The protector 55 is preferably formed as a single moulded item. An upper mounting means 56 is formed towards the upper end of the shield 57. The upper mounting means 56 comprises a substantially U-shaped gap

58 in the upper end of the shield 57 and the sides 59 of the gap are dimensioned to engage against the sides of a hacksaw frame (not shown) . Inwardly directed shoulders 60 on the sides of the gap 58 will act to retain the protector 55 to the upper part of the hacksaw frame. The lower part of the protector includes a pair of flanges 61 which locate on opposite sides of the handle of the hacksaw in the manner discussed in connection with previous embodiments. The gap 62 between the flanges 61 serves as the lower mounting means to thereby securely fix the protector 55 to the handle.

To improve the connection between the protector 55 and the handle of the hacksaw the protector is provided with a connector 63 intermediate the upper and lower mounting means. The connector 63 preferably comprises a pair of flanges 64 with inwardly directed lips 65 which in use locate behind the forward part of the handle of the hacksaw. The flanges 64 will be sufficiently resilient to enable the connector 63 to be clipped to the post for quick engagement with the post. The lips 65 preferably have a tapered lead-in edge to facilitate engagement with the post.

It will be appreciated that one of the major advantages of the protector device described herein is that it need not be permanently fitted to the handsaw. In many instances of use of a handsaw, a protector device of the type described herein would obstruct the sawing action. For example, where it is desirable to saw off a stud which projects laterally out of a flat surface it is necessary for the saw to lie substantially flush against the flat surface. If the protector device were permanently fixed to the handsaw it would not be possible to place the handsaw flush against the flat surface. It is thus preferable that the protector device is a simple clip-on or snap fit connection which allows for simple and fast mounting and removal of the device.

It will be understood that the terms "upper" and "lower" as used herein are not intended to imply that a handsaw with a device according to the invention fitted thereto can only be used in a particular orientation. The terms have been used simply to aid description and only apply of course, when the handsaw is in its conventional orientation, ie. when the handsaw is upright and the blade faces downwards.

From the aforegoing it will be evident that many different types of protector can be made and the design of the protector will, at least to some extent, depend on the form of handsaw to which the protector is adapted to be fitted. To some extent the same protector can be used with different types of handsaws and a degree of standardisation is desirable, but where the handsaws vary to too great an extent it will be necessary to have a specific form of protector adapted to fit any one specific handsaw .

Any suitable material can be used to form the protector. It is desirable that the protector is relatively lightweight so that the protector does not serve to unnecess- arily increase the mass of the handsaw when it is fitted to the handsaw. In certain circumstances, however, it may be desirable for the protector to be of high strength construction and in such circumstances a steel or other metal protector may be provided. Generally, however, it is envisaged that the protector will be moulded from a plastics material of a suitable strength and rigidity.

Many variations may be made to the above described embodiment without departing from the spirit or ambit of the invention as defined by the appended claims.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A protection device adapted to be releasably mounted to the handle of a handsaw, said device comprising a curved shield, an upper connection means on said shield for releasably connecting the device to an upper part of a said handsaw, and a lower connection means for releasably connecting the device to a lower part of the handsaw, said shield being dimensioned such that a users hand which operatively holds a handsaw to which said device is mounted will nest behind and thereby be protected by said device.

2. A device according to claim 1 wherein at least one of said upper and lower connection means is adapted to connect to a said handsaw through a releasable snap fit connection.

3. A device according to either claim 1 or 2 wherein said upper connection means and/or said lower connection means are integrally formed within said shield.

4. A device according to any preceding claim which includes a pair of rearwardly extending flanges connected to said shield at or near the operating lower part of said shield, said flanges being adapted to locate towards the lowermost part of and on opposite sides of the handle of a handsaw to which said device is mounted.

5. A device according to any preceding claim wherein said upper connection means comprises a substantially U-shaped recess in an upper part of said shield, said recess adapted to receive a part of the frame of a handsaw to which the device is operatively connected.

6. A device according to any preceding claim wherein said shield is of part circular cylindrical shape and is symmetrical about a plane which extends through said upper and lower connection means and includes the cylinder axis.

7. A device according to claim 1 wherein said upper connection means includes at least one mounting hole, and said device is adapted to be mounted to said handsaw through a fastener which passes through said mounting hole and said handsaw.

8. A device according to any preceding claim formed of a high strength substantially rigid plastics material.

9. A device according to any preceding claim which includes a connector intermediate said upper and lower connection means, said connector being adapted to releasably clip on to or part of the handle of said handsaw.

10. A combination of a device according to any preceding claim and a hacksaw, said upper connection means being releasably connected to an upper frame part of said hacksaw, and said lower connection means being releasably connected to a lower part of a handle of said hacksaw.

11. A combination according to claim 10 wherein said handle comprises a hand engageable portion and a post forward of said hand engageable portion and said handguard includes a releasable connector which clips onto said post to securely but releasably hold said handguard to said hacksaw.

SUBSTITUTE SHEET