US2797481A - Tool for cutting fibro-cement sheets or like material - Google Patents

Description

July 2, 1957 J. M. IGGULDEN 2,797,481

TOOL. FOR CUTTING FIBRO-CEMENT SHEETS OR LIKE MATERIAL Filed Nov. 28, 1955 1N VENTOR United States Patent O TOOL FOR CUTTING FIBRO-CEMENT SHEETS OR LIKE MATERIAL .lohn Manners Iggulden, East Brighton, Victoria, Australia Application November 28, 1955, Serial No. 549,461

Claims priority, application Australia December 1, 1954 1 Claim. (Cl. 30-242) This invention relates to an improved tool intended mainly for cutting fibro-eernent sheets, but usable also for cutting other sheet material such as composition board, tibro-plaster sheets, pressed thermosetting plastic building panels or the like.

Sheet material of the above character is often difficult to cut, particularly when the cuts are curved or are in the nature of apertures or shaped holes cut within the perimeter of the sheets. Usually such cuts are made by the use of narroW-bladed saws or like tools but these are not very eicient and the cuts made are often jagged. The cutting operation is also slow and laborious.

The present invention has for its object to overcome these disabilities and provide an improved form of tool by means of which curved and internal cuts in sheet materials as mentioned above can be made more expeditiously and with greater facility than at present.

According to the invention, the improved tool cornprises a body member, a holding handle attached there` to, a cutting blade slidably mounted in the body member, a fixed jaw supported from the body member to provide a mouth and having a slotted portion through which the cutting blade operates with a shearing action to shear a narrow strip from the sheet engaged in the mouth, an operating handle pivoted at an intermediate point to the body member, a pivot pin on the end of the operating handle, a pivot pin on the end of the cutting blade and links connecting said pivot pins so that the blade is operated by pivotal movement of the operating handle.

Preferably, a spike or pointed piercing blade is provided on the end of the holding handle for use in forming an initial hole in the libro-cement or other sheet to enable the tool to be inserted for use, and said spike or blade is normally covered by a slidable cover.

The invention is more fully described aided by reference to the accompanying drawings wherein:

Fig. 1 is a side view, partly in section, of the improved tool.

Fig. 2 is a part side View with portion in section illustrating the operation of the tool.

Fig. 3 is a horizontal section on line 3-3 of Fig. 1.

Fig. 4 is a sectional side view of the lower end of the holding handle.

As is shown in these views, the tool comprises a body member 1 attached as by spotwelding to the holding handle 2 and having at its upper end a fixed jaw 3. The body member comprises two side plates 4 spaced apart by spacers 5 and also having an extended member 6 which supports the jaw 3. The parts are shaped to provide the mouth 7 and are all preferably secured together by spotwelding to form a rigid structure of comparatively narrow width. f

The spacers 5 form a vertical slideway 8 in which is fitted the cutting blade 9, the latter having an angularly formed upper end 10 co-acting with an open-topped slot 11 in the fixed jaw 3.

Pivoted to the body member 1 at an intermediate point is an operating handle 12 having a handle part 13 atlce 2,797,481

an offset portion 14 extendingr between the side plates 4 i and pivotally connected by the pivot pin 15 to the lower ends of a pair of links 16. The upper ends of the links are pivotally connected by a pivot pin 17 to the lower end of the blade 9. The pins 15 and 17 are freely slidable in slots 18 in the side plates 4 of the body member.

'Ihe operation of the tool will be obvious. The sheet to be cut is engaged in the mouth 7 and the handle 12 operated to cause the blade 9 to be reciprocated to shear a narrow strip from the sheets, the tool, of course, being advanced as each cutis made. The width of the angular- 1y formed end 10 of the blade is'comparatively small so that only a relatively small portion is sheared from the sheet on each operation of the blade by the handle 12. This nibbling-like cutting action enables curved and internal cuts to be conveniently formed in the tibro-cement or like sheet material without causing unduly jagged edges and with greater speed and facility than previously. Moreover, as the portion sheared from the sheet on each operation is forced by the blade upwardly out through the opentopped slot 11 in the fixed jaw 3, the cutting blade is always maintained clear.

The gripping or hand portions of the handles 2 and 12 may be of tubular form made from sheet metal.

The lower end of the handle 2 may be provided with a spike or pointed piercing blade 19 for use in forming an initial hole in the fibre-cement or other sheet to enable the tool to be inserted for use. Said spike is preferably secured as by means of rivets 20 to the lower end of the handle and has a slidable cover 21 for protecting it when not in use.

The cover is tubular to embrace the lower end of the handle and may be retained in either of its two slidable positions by means of a pin 22 passed through slots 23 in the handle and engaging holding notches 24 in a U-shaped spring 25 secured to the handle by a pin 26. The pin 22 engages in either notch 24 at the end of the sliding movement of the cover to either expose or cover the blade 19 and the cover is thereby frictionally retained in either position by the closing action of the U-shaped spring 25.

What I claim is:

A tool for punching fibro-cement sheets or like material, comprising an elongate body member, a holding handle rigidly extending from one end of said body member, a xed jaw rigidly fixed at the other end of said body member and spaced therefrom to provide a material receiving mouth between said jaw and the adjacent end of said body member, said body member having a rectangular section slideway longitudinally therein opening through the end thereof perpendicular to said mouth and a slot in each side wall opening longitudinally into said slideway, said jaw having a slideway therethrough in alignment with and corresponding in size and section to said body slideway, a punch blade of rectangular section snugly slidable within said slideways and having a flat punch end facing said mouth, said punch end being inclined to the transverse plane of said blade and from the inner end toward the opening of said mouth, said body member having an opening in one edge thereof and in communication with said slideway and side wall slots, an operating handle having an operating end inserted in said opening and pivoted to said body member at an intermediate point with said operating end interposed between said slots, a pivot pin carried by said operating end and extending laterally from both sides thereof through the respective slots, a pivot pin on the inner end of said blade and extending laterally from both sides thereof and through the respective slots, and a pair of links respectively on each side of said body member and connected at their respective ends to said handle and blade pivot pins, whereby opera- Patented July 2, 1957 tion of said 4operating handlewill sldetsaidbladelongitudinally of said slideways and transversely of said mouth to punch a section from 4material inserted into said mouth and `expel the punchedsection through. Ibex-open end of saidjawslidevvay.` l v v References Cited'inthejleof this patent' UNITEDSTATES PATENTS 195,101 Davidson Sept. 11, 1877 4 Grabowenski Sept. 1, 1903 Potstada Feb. 25, 1908 Bush Dec. 5, 1916 Rowe et a1. Dec. 12, 1950 Hartwell Mar. 3, 1953

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