GB2148777A

GB2148777A - Improvements in hand tools

Info

Publication number: GB2148777A
Application number: GB08422560A
Authority: GB
Inventors: Christopher Roland Bo Harrison
Original assignee: Wilkinson Sword Ltd
Current assignee: Wilkinson Sword Ltd
Priority date: 1983-10-26
Filing date: 1984-09-06
Publication date: 1985-06-05
Also published as: GB8422560D0; GB8328577D0; GB2150067A; GB2150067B

Abstract

A hand tool of the type in which a tang 21, secured to a work engaging part 15 of the tool, is fitted to a tubular handle 13 by means of a sleeve 22 fitted closely within the handle and having an opening shaped to complement the shape of the tang. The tang which is preferably of rectangular section, is tapered along two of its opposite sides and the sleeve is split to enable expansion of the sleeve into tight engagement with the handle as the tang is forced in. <IMAGE>

Description

SPECIFICATION Improvements in hand tools This invention relates to hand tools of the type in which a tang, secured to a work-engaging part of the tool, is fitted into a tubular handle. One example of such a hand tool to which the present invention is particularly directed is a pair of longhandled lawn-edging shears, but equally the invention could be applied to a trowel and in general to a wide range of hand tools.

One disadvantage of such tools is that, even when the tang is tapered and forced into a hole suitably formed in the handle during manufacture of the tool, the handle frequently works loose during use and may become detached.

According to the present invention there is provided a hand tool having a work-engaging portion, a tang rigidly secured thereto, a tubular handle and a sleeve of plastics material split along its length and fitted closely within the tubular handle, the inner surface of the sleeve and the outer surface of the tang being shaped to cooperate, upon forcing the tang into the sleeve, in expanding the sleeve along its length into uniformly tight engagement with the tubular handle without circumferential strain in the sleeve.

In particular the tang is of rectangular cross-section with two sides of the tang tapering at an angle of 2" with respect to one another.

The invention will now be particularly described with reference to the accompanying drawings in which Figure 1 is a side elevation of lawn edging shears according to the invention; Figure 2 is a rear elevation of the shears with the handles omitted; and Figure 3 is a fragment of the shears of Figure 1 part shown in section and part in elevation.

The edging shears shown in Figure 1 comprise left and right blades 10, 11, forward and rearward handles 12, 13, and left and right blade supports 14, 15, the left blade support 14 being connected on the one hand to left blade 10 and forward handle 12, whereas the right blade support 15 is connected at one end to the right blade 11 and on the other hand to the rearward handle 13. A pivot bolt assembly 16 pivotally interconnects the blade supports 14 and 15.

Each blade support is a plastics moulding in which is embedded a steei tang 21 to which the associated handle 12 or 13 is fitted in a manner to be described below. The construction of the blade supports and the manner of their assembly with the blades supports is described in detail in our copending patent application No. 83.28577. The present invention is concerned with the assembly of the handles with the tangs.

Each tang 21 is of rectangular section, the major sides of the tang being parallel to each other and to the plane of the blades and the minor sides being perpendicular to the major sides and tapering towards the free end of the tang at an angle of substantially 2" with respect to each other.

Each tubular handle 12, 13 is fitted to the tang 21 of the corresponding blade by means of a plastics sleeve 22. Each sleeve 22 is formed with a rectangular section opening extending throughout its length and dimensioned along its length to complement the shape of the tang and so to form a tight fit with the corresponding part of the rectangular section tang.

At its lower end, as seen in the drawings, each sleeve is enlarged to form a rim or cuff 23 of greater dimensions than the sleeve to form an abutment between the lower end of the handle 12 or 13 and the upper end of the blade support 14 or 15, and to cover the lower end of the corresponding tubular handle. The sleeve is shaped and dimensioned externally to fit closely the internal surface of the handle which, in particular, is right cylindrical.

Moreover, the sleeve is slit over its entire length or substantialy the entire length, between the rim 23 and the free end of the sleeve, to permit the sleeve to expand without significant circumferential stress as the tang is forced into the handle. Although the sleeve is illustrated as being divided into two equal parts by the slits, more than two slits could be provided.

in the assembly of the shear, each plastics sleeve is first inserted fully into the lower end of the corresponding tubular handle until the rim abuts the end of the handle. Each handle and sleeve is then forced onto the tang and as the tapered tang progressively enters the sleeve, the longitudinal slit opens to allow the sleeve to expand into tight engagement both with the tang and with the inside of the tubular handle. The split formation of the sleeve enables the parts of the sleeve to move apart and so allow the tang to be forced into the sleeve without the expenditure of energy which would be needed to expand an unslit sleeve, and hence without circumferential strain in the sleeve.

The natural resilience of the plastics sleeve, the slit nature of the sleeve, the close fit between the sleeve and the inner surface of the tubular handle, and the slight taper of the tang all cooperate to produce a fit which becomes progressively tighter as the tang is forced in but with substantially even pressure within the sleeve along its length. This ensures a firm and lasting bond between the tang and the handle.

The two halves of the shear are finally fitted together and secured by the nut and bolt assembly.

1. A hand tool having a work-engaging portion, a tang rigidly secured thereto, a tubular handle, and a sleeve of plastics material split along its length and fitted closely within the tubular handle, the inner surface of the sleeve and the outer surface of the tang being shaped to cooperate, upon forcing the tang into the sleeve, in expanding the sleeve along its length into uniformly tight engagement with the tubular handle without circumferential strain in the sleeve.

2. A hand tool according to claim 1 wherein the

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements in hand tools This invention relates to hand tools of the type in which a tang, secured to a work-engaging part of the tool, is fitted into a tubular handle. One example of such a hand tool to which the present invention is particularly directed is a pair of longhandled lawn-edging shears, but equally the invention could be applied to a trowel and in general to a wide range of hand tools. One disadvantage of such tools is that, even when the tang is tapered and forced into a hole suitably formed in the handle during manufacture of the tool, the handle frequently works loose during use and may become detached. According to the present invention there is provided a hand tool having a work-engaging portion, a tang rigidly secured thereto, a tubular handle and a sleeve of plastics material split along its length and fitted closely within the tubular handle, the inner surface of the sleeve and the outer surface of the tang being shaped to cooperate, upon forcing the tang into the sleeve, in expanding the sleeve along its length into uniformly tight engagement with the tubular handle without circumferential strain in the sleeve. In particular the tang is of rectangular cross-section with two sides of the tang tapering at an angle of 2" with respect to one another. The invention will now be particularly described with reference to the accompanying drawings in which Figure 1 is a side elevation of lawn edging shears according to the invention; Figure 2 is a rear elevation of the shears with the handles omitted; and Figure 3 is a fragment of the shears of Figure 1 part shown in section and part in elevation. The edging shears shown in Figure 1 comprise left and right blades 10, 11, forward and rearward handles 12, 13, and left and right blade supports 14, 15, the left blade support 14 being connected on the one hand to left blade 10 and forward handle 12, whereas the right blade support 15 is connected at one end to the right blade 11 and on the other hand to the rearward handle 13. A pivot bolt assembly 16 pivotally interconnects the blade supports 14 and 15. Each blade support is a plastics moulding in which is embedded a steei tang 21 to which the associated handle 12 or 13 is fitted in a manner to be described below. The construction of the blade supports and the manner of their assembly with the blades supports is described in detail in our copending patent application No. 83.28577. The present invention is concerned with the assembly of the handles with the tangs. Each tang 21 is of rectangular section, the major sides of the tang being parallel to each other and to the plane of the blades and the minor sides being perpendicular to the major sides and tapering towards the free end of the tang at an angle of substantially 2" with respect to each other. Each tubular handle 12, 13 is fitted to the tang 21 of the corresponding blade by means of a plastics sleeve 22. Each sleeve 22 is formed with a rectangular section opening extending throughout its length and dimensioned along its length to complement the shape of the tang and so to form a tight fit with the corresponding part of the rectangular section tang. At its lower end, as seen in the drawings, each sleeve is enlarged to form a rim or cuff 23 of greater dimensions than the sleeve to form an abutment between the lower end of the handle 12 or 13 and the upper end of the blade support 14 or 15, and to cover the lower end of the corresponding tubular handle. The sleeve is shaped and dimensioned externally to fit closely the internal surface of the handle which, in particular, is right cylindrical. Moreover, the sleeve is slit over its entire length or substantialy the entire length, between the rim 23 and the free end of the sleeve, to permit the sleeve to expand without significant circumferential stress as the tang is forced into the handle. Although the sleeve is illustrated as being divided into two equal parts by the slits, more than two slits could be provided. in the assembly of the shear, each plastics sleeve is first inserted fully into the lower end of the corresponding tubular handle until the rim abuts the end of the handle. Each handle and sleeve is then forced onto the tang and as the tapered tang progressively enters the sleeve, the longitudinal slit opens to allow the sleeve to expand into tight engagement both with the tang and with the inside of the tubular handle. The split formation of the sleeve enables the parts of the sleeve to move apart and so allow the tang to be forced into the sleeve without the expenditure of energy which would be needed to expand an unslit sleeve, and hence without circumferential strain in the sleeve. The natural resilience of the plastics sleeve, the slit nature of the sleeve, the close fit between the sleeve and the inner surface of the tubular handle, and the slight taper of the tang all cooperate to produce a fit which becomes progressively tighter as the tang is forced in but with substantially even pressure within the sleeve along its length. This ensures a firm and lasting bond between the tang and the handle. The two halves of the shear are finally fitted together and secured by the nut and bolt assembly. CLAIMS

2. A hand tool according to claim 1 wherein the tang is of rectangular cross-section the major sides of which are parallel to one another and the minor sides of which are tapered in a direction towards the free end of the tang.

3. A hand tool according to claim 1 or claim 2 wherein the inner surface of the handle and the outer surface of the sleeve are right cylindrical.

4. A hand tool according to any preceding claim wherein the taper of the tang and of the opening in the sleeve is substantially 2".

5. A hand tool according to any preceding claim in which the sleeve terminates in a cuff which is not split and which has an external dimension greater than that of the sleeve to engage and cover the adjacent end of the tubular handle.

6. A hand tool as herein described with reference to the drawings.