Apparatus for hide stretching

A hide stretching apparatus, in particular one for the tentering of hides for drying. The apparatus comprises a stretching frame with a number of mutually spaced radial sliding guides. The stretching clamps gripping the edges of the hide have been arranged to be reciprocatingly movable along the sliding guides. The stretching frame is placed upon a special hide changing table carrying under each sliding guide a clamp displacement member. The clamps carry jaws which attach to the edge of the hide to be stretched. The jaws are opened and closed by means of a lever turnably carried on the clamp. The clamp displacement member has two gripping members, which can be made to engage the clamp on both sides according to commands given, for the displacing of the clamps reciprocatingly along the sliding guides. The clamp comprises a brake engaging with the sliding guide and which with the jaws in closed position prevents the displacement of the clamp towards the center of the stretching frame. The lever turning the jaws into their opened and closed position pushes, when the jaws are opened, the brake against the force of a spring into a position such that the clamp is free to move in either direction, whereby the clamps can be moved into clamping position and into detachment position.

I claim:

1. In a hide stretching apparatus, in particular for the tentering of wet hides for drying, of the type comprising in combination

a stretching frame having peripherally attached thereto and radially extending inwardly therefrom a plurality of guides, each of said guides having a first end affixed to said frame and a second end affixed to a center piece located centrally in said frame;

a like plurality of clamps, individual ones of said clamps being slidably attached to corresponding ones of said guides so as to be movable in an inward direction and an outward direction, respectively toward said second end and said first end of a corresponding one of said guides, each of said clamps being provided with a pair of jaws operable, by a lever provided each clamp, between an open position and a closed position, said jaws being so disposed and dimensioned as to be capable of grasping an edge of a hide when in said closed position and releasing said edge when in said open position, each of said clamps being further provided with a brake operable between a locked condition, wherein said brake engages with the corresponding one of said guides so as to prevent motion of said clamp along said corresponding one only in said inward direction, and an unlocked condition, wherein said brake is disengaged so as to allow said clamp to travel in both said inward direction and said outward direction; and

a hide changing table provided with a clamp displacement member for each of said clamps, said clamp displacement member being dimensioned and disposed so as to be capable of translating an individual one of said clamps along said corresponding one of said guides in both said inward direction and said outward direction under control of a detachment control and a stretching control;

the improvement comprising

a mechanical linkage between said lever and said brake so configured as to place said brake in said locked condition when said pair of jaws are moved by said lever into said closed position and to place said brake in said unlocked condition when said jaws are moved into said open position;

a first jaw of said pair of jaws being fixed relative to each of said clamps, a second jaw of said pair being attached to said first jaw through a pair of pivoting linkages; and

each said clamp displacement member is provided with a first gripping member which engages an inner edge of said individual one of said clamps to translate said individual one of said clamps in said outward direction, and a second gripping member which releasably engages an outer edge of said individual one of said clamps to impart a motion in said inward direction; said second gripping member being movably controlled relative to said clamp displacement member by said detachment control so as to be capable of engaging said outer edge only on command from said detachment control.

2. Apparatus according to claim 1, further including an additional pivot link connecting said lever with said second jaw.

3. Apparatus according to claim 1 further including a piston rod in a piston-and-cylinder means for engaging said second gripping means with said outer edge and simultaneously actuating said lever so as to move said jaws into said open position.

4. Apparatus according to claim 3 further including an edge sensor mounted on said clamp displacement member said edge sensor for sensing an edge of said hide and being so connected to said piston-and-cylinder means as to, upon sensing said edge activate said piston-and-cylinder means to disengage said second grippng member from said outer edge while at the same time releasing said lever, thereby closing said clamping jaws of said clamp.

5. Apparatus according to claim 1, further including a limit switch/valve attached to said first gripping member, said limit switch/valve being connected so as to control the engagement and disengagement of said second gripping member with said outer edge.

6. Apparatus according to claim 5, wherein further said stretching control is connected to the limit switch/valve for operating the latter to cause disengagement of said second gripping member from said outer edge.

7. Apparatus according to claim 4, wherein further said edge sensor is a mechanical contact sensor movably mounted on said clamp displacement means so as to move between a first and second position wherein respectively said edge sensor may and may not contact said hide and wherein said piston-and-cylinder means operating said second gripping member is connected to move said edge sensor to said first position when said second gripping member is engaged with said outer edge and to said second position when said second position when said second gripping member is disengaged.

8. Apparatus according to claim 1 wherein further said stretching frame has outwardly curved sides to which said first ends of said guides have been affixed, said sliding guides are a pair of steel wires on above the other, and said pairs of steel wires are spaced side by side sufficiently close that they alone constitute a supporting base for the hide.

9. Apparatus according to claim 1, wherein further said brake is a turnably carried lever acted upon by a spring and by an opposed pusher pin.