GB2104834A

GB2104834A - Hacksaw allowing replacement and tensioning of the blade

Info

Publication number: GB2104834A
Application number: GB08222894A
Authority: GB
Inventors: Keith John Sheldon
Original assignee: Precision Manufacturing Services Ltd
Current assignee: Precision Manufacturing Services Ltd
Priority date: 1981-08-27
Filing date: 1982-08-09
Publication date: 1983-03-16
Also published as: GB2104834B

Abstract

Each half of a two-part handle is provided with bearing and locating means for a winder (19) engaged by a screw threaded part (17) of a blade fixing member (12), apart (13) of the fixing member extending through a correspondingly shaped hole (14) in the assembled handle. <IMAGE>

Description

SPECIFICATION Saw This invention relates to saws, and is particularly, but not necessarily exclusively, concerned with hacksaws.

Hacksaws are normally constructed from a handle, a bow extending from the handle and a saw blade secured between the free end of the bow and the handle. To allow for the replacement of a blade and to allow for the tensioning of the blade it is usual to provide fixing means at the free end of the bow in the form of a member passing through an appropriately shaped hole in the bow and having a threaded portion on which is screwed a wing nut. By slackening the wing nut the mounting member can be urged inwardly of the bow to allow for the removal of the blade and its replacement by a fresh blade, and tightening of the wing nut firstly brings about the securing of the blade in place and secondly the inducing of the correct tension in the blade itself.It is however most inconvenient to have a protruding wing nut at the free end of the bow, and attempts have been made hitherto to provide an adjustable mounting member on the handle rather than at the end of the bow. Thus, it is known to have lever mechanism and/or screw mechanism to provide for the release of and the tensioning of a blade but all such versions known hitherto have provided such mechanism externally of the handle which is most inconvenient to the user during normal use of the saw itself.

The object of the present invention is to provide a saw, particularly a hacksaw, which avoids the inconveniences referred to above.

According to the present invention, a saw, particularly a hacksaw, comprises a two-part handle each half having provided therein bearing/locating means for a winder, a screw threaded part of a blade fixing member lying within the winder and a part of the fixing member, with the handle parts assembled, extending through a correspondingly sectioned hole in the handle, there being a bow extending from the handle and having a blade location means at the free end thereof.

Thus, the handle parts may have an upper portion of generally tubular configuration into which can be fitted one end of a correspondingly generally tubular bow, which may be there secured by means of a set screw. The generally tubular bow can conviently serve as a housing for a spare blade. From the generally tubular upper part there can be provided a downwardly extending hand grip, together with a downwardly extending finger guard longitudinally spaced from the hand grip. With such construction location and bearing means for the winder can be formed in each half of the handle towards the bottom end of the hand grip and towards the bottom end of the finger guard, the winder thus bridging the gap between the hand grip and the finger guard at its lower end.The extending part of the fixing member projects beyond the finger guard and can be advanced and retracted with respect to the saw handle by rotation of the winder thus allowing for the removal and replacement of a blade and its subsequent tensioning.

Normally, the blade fixing means on the handle and on the free end of the bow are oriented such that the plane of the blade coincides with the plane of the bow. Both, however may be oriented such that the plane of the blade is angularly disposed to the plane of the bow.

One embodiment of hacksaw in accordance with the invention will now be described with reference to the accompanying drawing which is a side elevation of a hacksaw.

In the drawing, a hacksaw 1 has a two-part handle 2, and two parts being held together by screws 3. Secured to the handle 2 is a generally tubular bow 4, one end of the bow extending into an appropriate hole formed between the handle halves and being held in place by a set screw 5 extending through co-operating holes in the frame halves and through a fixing hole on the bow. To enable the hacksaw to accommodate saw blades of different lengths, one or more additional fixing holes may be provided in the bow. The upper part of the bow can have located therein a spare hacksaw blade.

At the outer end of the bow blade, fixing means 6 are provided, the fixing means having a body portion 7 passing through an appropriate shaped hole 8 and there being a flat sided stem 9 with a pin 10 engaging an appropriate hole in a hacksaw blade 1 1 at that end. The hacksaw blade extends to fixing means 12 secured to the handle, the fixing means comprising a body portion 13 passing into a correspondingly shaped hole 14 formed between the handle halves, and having a flat faced recess 1 5 with a pin 16 to engage in an appropriate hole in the blade at that end. From the body portion 13 extends a screwed stem 17, said screwed stem engaging in a screwed hole 18 within a winder 19. The winder 19 has bearing and locating means formed by a stem 20 passing through a hole 21 formed between the handle halves to a head 22.The winder 19 has a gripping finger 23 which in its inoperative position lies in a recess 24 in a finger guard 25, the winder 19 bridging the gap between the finger guard 25 and the hand grip 26.

Thus, with a blade secured between the mounting members 6 and 12, the winder can be activated firstly to secure the blade in position by bringing about positive engagement with the pins 10 and 16, and secondly to induce the appropriate tension required in the blade.

Normally the blade 1 1 will be utilised in a plane coincident with the plane of the bow 4.

However to allow it to be used in different configurations, it is preferred that the body portions 7 and 13 of the mounting members are square so that the blade can be held at 900 to the plane of the bow with the teeth facing in either direction.

By providing an adjustable mounting member for the saw blade on the handle, those problems associated with the provision of a wing nut at the free end of the bow are eliminated, and by providing bearing and locating means for the winder in the handle parts, those problems associated with externally mounted means on the handle are also eliminated.

The invention therefore provides a very simple and very efficient form of adjustable mounting for a saw blade in, e.g., a hacksaw.

Claims

1. A saw, particularly a hacksaw comprising a two-part handle each half having provided therein bearing/locating means for a winder, a screw threaded part of a blade fixing member lying within the winder and a part of the fixing member, with the handle parts assembled, extending through a correspondingly sectioned hole in the handle, there being a bow extending from the handle and having blade location means at the free end thereof.

2. A saw as in Claim 1, wherein the handle parts have an upper portion of generally tubular configuration into which can be fitted one end of a correspondingly generally tubular bow.

3. A saw as in Claim 1 or Claim 2, wherein the bow serves as a housing for a replacement hacksaw blade.

4. A saw as in any of Claims 1 to 3, wherein from the generally tubular upper part there is provided a downwardly extending hand grip, together with a downwardly extending finger guard longitudinally spaced from the hand grip, the location and bearing means for the winder is formed in each half of the handle towards the bottom end of the hand grip and towards the bottom end of the finger guard, the winder thus bridging the gap between the hand grip and the finger guard at its lower end.

5. A saw as in any of Claims 1 to 4, wherein the blade fixing means on the handle and on the free end of the bow are oriented such that the plane of the blade coincides with the plane of the bow.

6. A saw as in any of Claims 1 to 5, wherein the blade fixing means on the handle and on the free end of the bow are oriented such that the plane of the blade is oriented such that the plane of the blade is angularly disposed to the plane of the bow.

7. A saw, particularly a hacksaw, substantially as hereinbefore described with reference to the accompanying drawing.