US2914889A - Clamping device - Google Patents

Description

De. 1, 1.959 B. H. MosBAcHER CLAMPING DEVICE Uriginal Filed July 28, 14955 United States Patent() CLAMPING DEVICE Bruce H. Mosbacher, Rockford, Ill., assignor to Sundstrand Corporation, a corporation of Illinois Original application July 28, 1955, Serial No. 524,896,

now Patent No. 2,795,901, datedv June' 18,1957. Divided and this application April 25 1957, Serial No. 655,044

This invention' relates to clampingdevices' and particu-l larly to' a device for clamping sheets of abrading material to a rubbing' and abrading machine.

This is a divisional application of my co-pending application on a Rubbing and Abrading Machine, Serial No. 524,896, tiled. July 22?,` 1955,` now Patent No. 2,795,901 issued June 18, 1957.

Various important objects' of this invention are to provide an improved. clamp for securing' sheets of abrasive material to the shoe of a rubbing and abrading machine, which clamp is compact and durable in construction, adapted' for clamping one or a` multiplicity of sheets of abrading material to the abrading shoe, and is simple to use and reliable iniopera'tionf.

i These; together with various ancillary' objects and advantages of this invention will be more readily appreciated as the same becomes better understood by reference to the following detailed description when taken in connection with the accompanying drawings wherein:

Figure 1 is a side elevational View of an abrading machine having the clamping devices of the present invention mounted thereon, and with one of the clamping devices shown in section to illustrate details of construction;

Figure 2 is an enlarged fragmentary top plan view of an abrading shoe and clamping device; and

Figure 3 is an end elevational view of the abrading machine and clamping device.

The abrading machine is more specifically disclosed and claimed in my co-pending application, Serial No. 524,896 (Patent No. 2,795,901), to which reference is made for a more complete description. The abrading machine in general includes a cast body having a track 11 mounted at lthe underside thereof. An abrading shoe 12 is reciprocably mounted on the track 11 and extends outwardly beyond the ends thereof, in all operative positions of the shoe. A pad 13 is provided at the underside of the shoe. A motor (not shown) is disposed in the cast body and operatively connected to the shoe 12 for reciprocating the same.

A clamping device 15 is provided at each end of the abrading shoe for clamping the sheets of abrasive material thereto. The clamping devices are located at the upper side of the abrading shoe inwardly of the ends thereof to prevent the clamps from engaging objects during manipulation of the abrading machine, and as best shown in Figure l, are each mounted on laterally spaced posts or projections 16 which are provided on the end portions of the shoe and extend upwardly therefrom. The clamping device includes a generally U-shaped clamp member 18 formed of resilient, relatively heavy gauge sheet stock. The clamp member is movably mounted on the posts 16 and extends therebetween with the leg portions thereof extending downwardly on opposite sides of the posts. The clamp member is preferably swingably supported on the posts and, as illustrated, is provided with depending ears 19 which are pivotally attached by fasteners 21 to the posts adjacent the upper ends thereof. The outer leg of the clamp member is rolled outwardly, as indicated at ICC 22to provide a smooth transversely rounded gripping edge.

which cooperates with the end of the shoe 12 to clamp the sheet or sheets of abrasive material therebetween. For reasons set forth hereinafter, the U-shaped clamp member is preferably formed in a smooth curve.

An operating lever 25 is disposed between the posts=16 and is pivotally mounted thereon by a pin 26 for movement about an` axis spaced above the lower edges of the U-shaped member 18. Rings 27 are provided on the ends of the pin 26 toy prevent accidental dislodgement thereof. The lever 25 extends upwardly through an enlarged opening 3 1 formed in the U-shaped clamp member which opening` terminates inwardly of the side edges andy ends ofthe clamp member. A longitudinally arcuate grippertion 33 is provided on the free end of the lever andA extends transversely thereto vto facilitate manipulation of the-lever.

A cam finger 35' is provided on the lower end of the lever within the U-shaped'clamp member and extends laterally inwardly ofthe pivot pin 26. The. cam finger has.

portions, herein illustrated' as rollers 36, provided thereonr for engagingvv the inner face of the clamp member, adjacent opposite sides of the opening 31, to swing the clamp member about the pivots therefor and thereby move the clamping edge 22v into its clamped position. As previously described, the pivot axisA of the lever is disposed above the lower edges. of the clamp member and the. rollers 3'6 are movable pastA auf over-center position, i-.e. beyond a line between the lever pivot axis and thev nearest part ofthe clamp member so that the resilient clamp member will yieldably retain the lever in its clamped position until manually released. As is apparent from Figure 1, the pivot axis of the lever is spaced from the arched web portion of the clamp member a distance greater than the effective length of the cam nger so that the roller thereon moves out of engagement with the clamp member as the lever is moved to its release position, illustrated at the right inFigure l. The clamp member can then swing outwardly about the pivot pin 21 to release the sheet or sheets of abrasive material clamped thereby. Any suitable means may be provided for moving the clamp member to its release position and, in the embodiment illustrated, pins 39 are provided on the lever to engage the inner face of the clamp member, adjacent opposite sides of the opening 31 therein, when the lever is moved to its release position. In this manner, the clamp member is pivoted about the fasteners 21 to swing the edge 22 thereof outwardly away from the adjacent end of the shoe to release the abrasive sheets.

It is apparent from the foregoing that the support posts 16, on which the clamp member is mounted, and the cam linger 25 and rollers 36 are disposed within the U-shaped clamp member and that only the operating lever 25 extends outwardly therefrom. This provides a compact clamping device especially adapted for use on the movable shoe of an abrading machine, and which can be easily manipulated with one hand. The U-shaped clamp member is suiciently resilient to accommodate one or several sheets of abrasive. Thus, a number of sheets of abrasive can be loaded onto the shoe and the lowermost sheet merely torn off when it becomes worn.

What is claimed as new is:

1. A clamp for attaching a sheet to a support cornprising an inverted generally U-shaped clamp member of resilient sheet stock having spaced leg portions with lower edges and an intermediate transversely arcuate web portion having an outer convex side and an inner concave side, one of said leg portions dening a clamping jaw, spaced apart means one at each side of the member pivotally mounting the web portion of' said member on said support for pivotal movement about an axis extending Patented Dec. 1,1959

3 longitudinally of said member, said member having an elongated opening therein spaced inwardly from the lower edges of said leg portions, a lever pivotally mounted ou said support between said leg portions of said member and generally beneath the member mounting means for movement about an axis extending longitudinally of said member, said lever extending outwardly through said opening and having a hand grip portion on an outer end thereof arranged to lie in all operative positions thereof at the convex side of said clamp member and intermediate the lower edges of said leg portions, said lever being movable from a generally upright clamping position at one side of the pivot axis of said clamp member to a release position at the other side of the pivot axis of said clamp member, and a cam finger on said lever at the concave side of said clamp member and engageablewith the other of said leg portions thereof to swing said clamp member about the pivot axis thereof and thereby move the jaw into clamping position.

2. A clamp as defined in claim 1 in which the pivot axis of the lever is spaced from the arcuate web portion a distance greater than lthe effective length of the cam finger whereby the finger moves out of engagement with the other leg portion as the lever moves to its release position, and means on the lever to engage the clamp member and move the jaw from its clamping position as the lever is moved to its release position.

3. In combination, a rubbing shoe, a clamp for clamping an abrasive sheet to the shoe, comprising a support atan end of the shoe having a pair of spaced posts, a downwardly facing generally U-shaped clamp member of resilient sheet stock disposed over said support and having depending leg portions disposed on opposite sides of the posts and an intermediate connecting web portion, one of said leg portions defining a clamping jaw, a depending ear at each side of the web portion, a pair of fasteners associated one with each ear and an adjacent post to pivotally mount the clamp member on the support for movement about a pivot axis, means defining an elongated opening in the clamp member extending in a direction transverse to the pivot axis of the clamp member, a -lever pivotally mounted on said posts for movement about a pivot axis disposed beneath the clamp member pivot axis, said lever extending outwardly through said opening and being movable from a generally upright clamping position at one side of the clamp member pivot axis to a release position at the other side of the clamp member pivot axis, roller means mounted on said lever offset from the lever pivot axis and engageable with the other of said leg portions for swinging the clamp member about the clamp member pivot axis to move the jaw into clamping position against the shoe, and pins on the lever engageable with the clamp member to move ythe jaw from clamping position as the lever is moved to its jaw releasing postion.

References Cited in the le of this patent UNITED STATES PATENTS 991,084 Riquette May 2, 1911 2,242,545 Randolph May 20, 1941 2,282,043 Ekstrom May 5, 1942 2,395,537 Crosby Feb. 26, 1946 FOREIGN PATENTS 618,684 Great Britain Feb. 25, 1949

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