Abstract:
A clamp for locking at least one pin ( 30 ) or the like, comprising a hollow body ( 1 ) provided with coaxial apertures ( 9 ) and in which there is mounted, slidable but not rotatable, a member ( 11 ) loaded by a spring ( 10 ) and provided with a through hole ( 12 ) able to align with said coaxial apertures ( 9 ) for passage of said pin ( 30 ), and connected axially but not rotatably to an operating knob ( 18 ) able to assume and maintain two positions, namely one in which the pin ( 30 ) is released by moving said member against the action of the spring ( 10 ) and one in which the pin is locked by the action of the spring.

Description:
FIELD OF THE INVENTION 
     This invention relates to a clamp for support and connection members such as pins and the like, particularly but not exclusively as used in conveyor belts for supporting the relative guides, for example lateral guides. 
     BACKGROUND OF THE INVENTION 
     With particular but not exclusive reference to conveyor belts, these are known to comprise later al guides formed for example from longitudinal section bars, which are supported by pins mounted in clamps. With these known clamps, the pins are clamped by screw means and can be adjusted by slackening and tightening these latter. 
     The operations involved in slackening and tightening these screw means in order to position the lateral guides in the desired manner are relatively burdonsome in terms both of time taken and force required, especially considering that in a conveyor belt complex of one and the same production plant there can be some hundreds if not thousands of such clamps. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     The main object of the invention is therefore to provide a clamp which eliminates the need to use screw means for locking the clamped piece or component (such as a pin) by using for its tightening the action of elastic means and for its slackening a manual action counteracting that of said elastic means. 
     Another object of the invention is to provide a clamp in which its tightening is achieved by the action of elastic means and its slackening by a manual counteraction which locks the clamp in the slackened position (in which the required adjustment can be made), from which tightening can be again achieved by releasing the clamp from this position. 
     A further object of the invention is to provide a clamp in which it is easier and quicker to position the clamped piece or pin and adjust the length of that portion thereof which projects from the clamp. 
     As there exists, not only in the conveyor belt sector, the need for a cross-type clamp, ie a clamp which clamps two separate members positioned at a right angle, a further object of the invention is to provide a cross-type clamp in which the tightening and slackening procedures of the two preceding objects apply to at least one of these members. 
    
    
     These and further objects which will be more apparent from the ensuing detailed description are attained by a clamp in accordance with the teachings of the accompanying claims. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a first embodiment of a clamp of the invention; 
     FIG. 2 is a side view of the body of the clamp of FIG. 1; 
     FIG. 3 is an enlarged side view of the upper part of FIG. 2; 
     FIG. 4 is an enlarged section through the lower part of the body of FIG. 2; 
     FIG. 5 is a perspective view of a second embodiment of the clamp according to the invention; and 
     FIG. 6 is a perspective view of a third embodiment of the clamp according to the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to FIGS. 1 to  4 , the clamp of the illustrated embodiment comprises an approximately cylindrical outer body  1  constructed of a known plastic, for example an engineering polymer. The body has an axial bore which in its upper portion  2  (on the drawing) has a polygonal cross-section, for example hexagonal. This upper portion is followed by a substantially circular lower portion  3  (on the drawing) of diameter such that the two portions  2  and  3  meet at a step  4 . The lower portion  3  has a terminal part  5  also of circular section but of reduced diameter. 
     The outer body  1  has an upper extension  1 A of lesser outer diameter than the remaining part. 
     In diametrically opposite positions of the extension  1 A there are provided equal but opposite guide apertures  6  and  7  defined by a descending rectilinear portion  6 A,  7 A, and a portion  6 B,  7 B with its longitudinal axis lying in a plane perpendicular to the longitudinal axis of the body  1 , the portion  6 B,  7 B terminating with a recess  6 C,  7 C directed upwards (on the drawing). 
     The body  1  also comprises two diametrically opposing coaxial equal rectangular apertures  8  and two axially spaced-apart equal coaxial circular holes, their common axis lying at 90° to the common axis of said rectangular apertures. 
     The terms “apertures” and “bores” are used interchangeably herein. It is to be understood that the term “coaxially bore” and “coaxially aperture” when used herein refers to the apertures/bores  8  and  9  in the drawings. 
     The body  1  houses: 
     a) an internally threaded and externally knurled bush  8 A which as shown in FIG. 4 is forced into the terminal part  5 ; 
     b) a washer  39 , preferably upwardly (with reference to FIG. 1) convex which rests on the step  4  and serves as a support for 
     c) a compression spring  10 , the other end of which bears on 
     d) a member  11  having a transverse circular through hole  12  (preferably comprising at its mid length an annular projection  13 ) and, at the opposite end to that on which the spring bears, an appendix  14  provided with one or more annular projections  15 , the member  11  having a polygonal cross-section which mates with that of the upper portion  2  of the bore through the body  1  so as to be able to slide therein but not rotate; 
     e) a snap ring  16 , which is inserted into an inner annular groove  17  in the body  1  to retain the aforesaid internal parts ( 9  to  11 ) with in the body. 
     On the appendix  14  of the member  11  there is snap-fitted in known manner a knob  18  in such a manner that it can rotate about said member  11  but cannot move axially on it. 
     Transversely to and radially within the knob  18 , which is of engineering polymer, there are positioned two mutually coaxial metal pegs  19  located to penetrate respectively into the profiled guide apertures  6  and  7  provided in the extension  1 A of the body  1 . These pegs are shown outside the knob  18  in FIG.  1 . 
     With the threaded bush  8 A there cooperates a knob  20  with screw  21  for tightening a section bar  21  positioned through the rectangular apertures  8 . On rotating the knob in one direction, the end of the screw  21  is forced against the section bar to lock it against the upper (with reference to the drawing) edge of the apertures  8 . On rotating the knob in the other direction the section bar is released. 
     When the other knob, ie the knob  18 , is rotated manually from the position in which the relative pegs  19  lie at the upper end of the portions  6 A,  7 A of the guides  6 ,  7  to the position in which they lie within the recesses  6 C,  7 C, there is firstly a downward (with reference to the drawing) movement both of the knob  18  and of the member  11  against the action of the spring  10 , then along the portion  6 B and  7 B the knob alone rotates, and finally there is a slight upward (with reference to the drawing) movement of the knob  18  and member  11  because of the entry of the pegs  19  into the recesses  6 C and  7 C. Both at the end of the downward movement and at the end of the small rise due to the recesses  6 C,  7 C there is virtual coaxiality between the holes  9  and the through hole  12  of the member  11 , so that a pin  30  can be removed or be moved into the desired position, in which one of its grooves  31  is made to coincide with the annular projection  13  in the member  11 . On rotating the knob in the reverse direction, ie such that the relative pegs  19  move from the recesses  6 C,  7 C to the upper (with reference to the drawing) ends  6 A,  7 A of the guide apertures  6 ,  7 . the member  11  moves upwards (with reference to the drawing) under the action of the spring  10 , with the result that the through hole loses its coaxiality with the holes  9  of the body  1 , the projection  13  in the member  11  penetrates into the desired groove ( 31 ) of the pin  30 , and this latter is locked in position. 
     Two things are evident. Firstly, the size of the through hole  12  at the relative annular projection  13  must be such as to enable the pin  30  to pass when the through hole  12  is substantially coaxial with the holes  9  of the body  1  and, when in the locked (ie non-coaxial) state, enable the annular projection  11  to enter the groove  31  in the pin  30  and this latter to lock against the upper (with reference to the drawing) edges of the holes  9 . Secondly, on assembly, the member  11  must be mounted in the body  1  such that the relative through hole  12  lies on the same side as the holes  9  of the body  1 . 
     In the embodiment of FIG. 5, a circular rod  50  is to be clamped by the screw knob  51  instead of the section bar of FIG.  1 . 
     In this case circular apertures  52  are provided instead of the rectangular apertures  8 . 
     The scope of the invention also includes a clamp which excludes those parts used to clamp the section bar  21  and the rod  50 , and hence limited to those parts relative to clamping the pin  30  and to maintaining it in its released position (for adjustment purposes). 
     The scope of the invention also includes an embodiment in which for clamping and releasing (and maintaining the released position of) a section bar or a rod  50 , those parts provided for this purpose for the pin  30  and already described in detail are used. 
     FIG. 6 shows a third embodiment of the clamp according to the invention which includes a hollow body ( 1 ) of the clamp assembly includes an additional coaxial bore ( 9 ) and an additional spring ( 10 ) arranged within the hollow body ( 1 ). FIG. 6 also reveals that an additional slidable but not rotatable member ( 11 ) is mounted in the hollow body ( 1 ), and is loaded by the additional spring ( 10 ), the additional member ( 11 ) having a through hole ( 12 ) aligning with the bore ( 9 ) formed in the hollow body ( 1 ). The through hole ( 12 ) is receives at least one pin such that the pin is insertable through the additional member ( 11 ) and the hollow body ( 1 ). FIG. 6 also shows an additional knob ( 18 ) connected to the member ( 11 ). The knob ( 18 ) has a first position in which the knob ( 18 ) is moved against action of the additional spring ( 10 ) such that the pin is released and a second position in which the additional knob ( 18 ) is locked by the action of the additional spring ( 10 ) such that the pin is locked. 
     The scope of the invention also includes different means for locking the knob  18  in the position which enables the pin  30  to be moved than those already described. These locking means could for example comprise a peg  41  (FIG. 1) to be inserted into through holes  42 ,  43  (FIGS. 1 and 3) provided in the lateral wall  18 A of the knob  18  and of the extension  1 A of the body  1 . These through holes  42 ,  43  are provided such that when the knob is in the position which enables the pin  30  to move, they are mutually coaxial, so enabling the peg  41  to be inserted to lock the knob. 
     Advantageously, the pin  30  comprises along its body a plurality of preferably recessed equidistant reference lines  44  (shown dashed in FIG.  1 ). These reference lines simplify and facilitate the operations required to adjust the length of that pin portion projecting from the clamp. In this respect, when a conveyor belt has to handle products, such as bottles, of different dimensions from the previously handled products, the position of all the pins has to be adjusted. The presence of the reference lines on the pin considerably facilitates this operation. Advantageously, the lines are made distinguishable from each other by marking each with a different recognition sign  70  such as, a different number or a different colour.