US2732175A

US2732175A - Web stretching device

Info

Publication number: US2732175A
Authority: US
Publication date: 1956-01-24
Anticipated expiration: 1973-01-24

Description

Jan. 24,- 1956 s. w. MOUNT 2,732,175

WEB STRETCHING DEVICE Filed Feb. 12, 1953 INVENTOR GEORGE W MOUNT ATTORNEYS WEB STRETCHING DEVICE George W. Mount, Greenfield, Mass.

Application February 12, 1953, Serial No. 336,580

1 Claim. (Cl. 254-79) This invention relates to an improvement in devices used by upholsterers for stretching upholstery webbing and holding the webbing in stretched condition while being tacked or otherwise secured in place.

Devices of this kind previously proposed have in general comprised an implement including a handle at one end with means intermediate the opposite end and the handle for gripping the web, the end opposite the handle being used as a fulcrum about which the implement is rotated to stretch the web. The web gripping means has comprised clamping devices, saw toothed metal edges or pins on which the webbing is impaled. Clamping means are expensive and time consuming in use, while saw teeth frequently fail to penetrate heavy webbing sufiiciently to securely hold the web. Separate metal pins have proved preferable but tend to unduly separate and displace the individual strands of which the webbing is formed resulting in uneven stretching and damage to the webbing.

It is the principal object of the present invention to overcome the above difliculties and provide a pin type stretcher which can be manufactured at a reasonable cost and which is capable of exerting a high tension on heavy webs with a minimum displacement of the web strands and without damage to the implement.

In the accompanying drawing:

Fig. 1 is a top plan View of a stretcher embodying the invention;

Fig. 2 is a side elevational view of the structure shown in Fig. 1, looking from the right of the latter figure; and

Fig. 3 is a diagrammatic view showing the manner of using the stretcher.

Referring to the drawing the stretcher is shown as comprising a block of wood 1 which is generally oblate or elliptical in cross section. One end face of the block is grooved as at 2 in the direction of the major axis of the block. Adjacent the forward edge of the block a bore 3 extends inwardly from the floor of groove 2. One end 4 of a handle member, generally indicated at 5, is seated in bore 3. The adjacent portion 6 of the handle member, which is preferably formed from metal rod stock, is bent at right angles to the portion 4 and seats in groove 2, the groove being of a width and depth to accommodate the diameter of the handle member. A third portion 7 of the handle is bent at right angles to portion 6, in the plane of portions 4 and 6 and a fourth portion 8 is bent at right angles to portion 7 and in the same plane. Portion 8 is provided with a hand grip 9 of any suitable material. The portion 6 is held in the groove 2 by means of a staple 10.

The exact form of curvature of the forward edge 11 and of the rear edge 12 of the block is not critical except that for reasons later pointed out they should approximate arcs of about one half inch radius, and the distance a between the edges preferably approximates two inches.

The forward or fulcrum edge 11 is covered over its effective arcuate surface with a sheet of anti-skid material,

United States Patent 2,732,175 i atented Jan. 24, 1956 as indicated at 13, such as ribbed rubber, leather or the like, cemented or otherwise held in place.

The rear edge 12 is provided with a plurality of spaced pointed pins 14 of steel or other suitable material. The pins 14 are tightly and firmly seated in openings 15 drilled in block 1 and extend to a depth to firmly hold the pins in position. The pins 14 are provided with tapering points 16 and extend outwardly of the block a suflicient distance to extend cleanly through the webbing with a sufficient length of the cylindrical portions 17 of the pins extending outwardly of the block to accommodate the thickness of the webbing so that there is no tendency for the webbing to ride up on the conical surface of the pins when initial stretching tension is applied to the web.

The length of handle portion 7 is such as to substantially center the grip 9 with respect to the block and portions 6 and 8 are of a length to afiord leverage for applying adequate stretching tension to the web without excessive effort.

In operation one end of a length of webbing w is tacked as at t to one side of a chair frame f, for example. The webbing is carried over the frame and impaled on pins 14 to seat the webbing material against the cylindrical portions 17 of the pins. The fulcrum end 11 of the implement is then placed against the adjacent face of the frame with the handle in nearly vertical position, as shown in Fig. 3. Upon swinging the implement downwardly about its fulcrum end in the direction of the arrow in Fig. 3 stretching tension is applied to the webbing. Due to the substantial radius of curvature of the block at the pin carrying edge 12, the web comes into frictional surface engagement with the block over a substantial and increasing area as the stretching proceeds and the tension in the web increases. This increasing area of contact of the Web with the block tends to decrease the strain of the pins on the web and to minimize the tendency of the pins to rupture or seriously displace the strands of which the webbing is formed. The substantial radius of curvature of the block at the fulcrum edge 11 causes the block to roll downward over the engaged surface of the frame lowering the web into contact with the upper surface of the frame facilitating a quick and easy application and stretch of the webbing into position for tacking.

What is claimed is:

A web stretcher comprising an elongated block having opposed parallel arcuate edges of substantially onehalf inch cross-sectional radius and spaced substantially two inches apart, a handle extending from one end of the block in the direction of the width of the block, and inwardly, substantially half the length of the block in spaced relation to the adjacent arcuate edge of the block, and outwardly therefrom at substantially right angles thereto, the arcuate longitudinal edge of the block remote from the handle being provided with a friction surface and forming a rolling fulcrum about which the block may be swung by said handle, the arcuate longitudinal edge of the block adjacent the handle being provided along its center line with a row of spaced web engaging pins extending radially from said arcuate edge, the arcuate surface at either side of said row of pins providing a substantially uniformly increased area of surface engagement of the web and block as increasing tension is applied to a web, engaged by the pins, upon swinging movement of the block about the opposite arcuate edge as a fulcrum.

References Cited in the file of this patent UNITED STATES PATENTS 432,428 Morton July 15, 1890 1,503,314 French July 29, 1924 1,514,273 Von Schenk Nov. 4, 1924 2,608,793 Gant Sept. 2, 1952