Abstract:
An installation head adapted to receive a fastener for securing the fastener to a sheet metal member on actuation of the head by a press. The head includes a main block having a bore, a cylindrical press member disposed within and supported by the bore, the press member having an arrangement for receiving and holding the fastener, wherein the cylindrical press member is rotatable in the bore between a first position, in which the fastener is received by the arrangement for receiving and holding the fastener and held in position relative to the press member, and a second position for actuation of the press.

Description:
FIELD OF THE INVENTION 
     This invention relates to a delivery system device for feeding parts, particularly fasteners such as nuts and studs to progression or transfer presses, and to a press or installation head for pressing the fastener into another component such as a sheet metal member. 
     BACKGROUND 
     When mounting a flanged nut or a flanged head stud, such as that sold by the applicants under the trade mark FLANGEFORM and generally described in GB-A-1 474 766, to a formed sheet metal part it is desirable to fix the stud at the same time as performing other pressing operations. 
     A known problem in the handling of studs in such presses is to ensure correct placement and orientation of the stud throughout its path from a supply container (in which the studs are simply randomly oriented) to its final position fixed to the desired component, e.g. a metal sheet, in the desired position by the press. Studs have a tendency to adopt the wrong position, and if this happens, serious consequences can arise, ranging from an increase in the number of studs inadequately fixed to jamming of the press with consequential loss of production time or even damage to press tools or other components of the press. 
     By providing better stud positioning and control throughout the path from the supply container to fixture by the press, the incidence of inadequate fixing or other failures can be substantially reduced. 
     SUMMARY OF THE INVENTION 
     A first aspect of the present invention provides a press adapted to receive a fastener for securing the fastener to a sheet metal member on actuation of the press, the press comprising a press member which has means for receiving and holding the fastener, wherein the press member is movable between a first position for receiving the fastener and a second position for actuation of the press. 
     It will be appreciated that the press member may be incorporated in a part of the press head which is moved during the pressing operation. 
     In a particularly preferred form, the press member receiving and holding means is adapted to receive and hold a shank of a stud. 
     A second aspect of the invention provides a stud loading mechanism comprising a breech; a plurality of members at an exit end of the breech and biased towards each other, the members forming a tapered outlet at the exit end of the breech; and reciprocating means in the breech adapted to effect a forward stroke to push a stud shank first along the breech towards the tapered outlet and then to push it further until the head of the stud has passed through the tapered outlet while forcing the members apart, and then to execute a retraction stroke. 
     The tapered aperture may be formed by elongate pivoted members, and serves to align the stud and help control the ejection of the stud from the breech. 
     Preferably the loading mechanism is used in combination with the press. 
     Other preferred features of the invention will be apparent from the following description and the accompanying claims. 
     The invention will now be described by way of example with reference to the accompanying drawings in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1 and 2  illustrate part of a delivery system according to the invention in part vertical section with a press head and a stud each in two different positions; 
         FIGS. 3 and 4  illustrate a part of the system shown in  FIGS. 1 and 2  in part horizontal section showing a pair of pivoted members of the stud feed mechanism in two different positions; 
         FIG. 5  is a side view of the system of  FIG. 1 ; 
         FIGS. 6 and 7  are partial sections along the section lines A—A and B—B in  FIG. 5 ; and 
         FIG. 8  shows schematically a control arrangement for the system. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 and 2  show parts of a press head for a press and comprising a main block  50 , vertically reciprocable by means not shown, and incorporating a delivery device indicated generally as  10 . The delivery device  10  is connected to one end of a delivery tube  12  along which studs  14 , having a shank  16  and a head  18 , are fed shank-first. They are fed into the upper end of tube  12  (not shown) by a conventional vibratory bowl feed means (not shown). Below the outlet of delivery tube  12  is a breech  20  set in a tool body  22  into which the studs  14  fall. 
       FIG. 3  shows that the breech  20  from above, and shows, in particular, a pair of pivoted members  24 , 26  pivoted at their ends adjacent the feed tube  12  by vertical axis pivots  28 , 30 , and biased towards each other by means not shown. The pivoted members  24 , 26  are shaped so that they curved upwards from their contiguous edges to form a half barrel in which a stud can lie (as shown in  FIG. 7 ). 
     The ends of the pivoted members  24 , 26  remote from the pivots  28 , 30  are shaped to form a conical aperture  34 . At the other end of the breech  20  adjacent the feed tube  12  there is an aperture  36  on the breech centre line; a thrust member  38  is located inside the breech  20  and is reciprocable within the breech by a double-acting piston cylinder  40 . The piston is pneumatically operable, as indicated by the pressure/exhaust ports  42 ,  44 , connected to a pressure source not shown, and reciprocation of the piston is controllable by a microswitch  46 . 
       FIG. 1  shows a stud  14  just before it falls into the breech  20 .  FIG. 2  shows the stud after falling; it lies with its head adjacent the thrust member  38  and its central axis sloping downwards because the tip  17  of the stud shank  16  lies on the floor of the half barrel. 
     As the piston  40  operates to move the thrust member  38  along the breech  20 , the stud  14  is pushed so that its tip  17  rides up the tapering aperture  34  until the stud central axis is horizontal, and the stud shank  16  is then pressed through the exit aperture  35 . 
     So far the pivoted members  24 , 26  have not moved. As the thrust member  38  moves the stud  14  further along the breech, so that the head  18  of the stud reaches the tapered aperture  34 , the pivoted members  24 , 26  pivot to provide a wider aperture to allow the head to pass. This can be seen in  FIG. 4 . After the stud head has left the breech  20 , the pivoted members are returned to their position shown in  FIG. 3  by the spring means (not shown). The piston cylinder  40  retracts the thrust member  38  until it is clear of the end of the delivery tube  12 , and another stud is delivered into the breech  20  i.e. as shown in  FIG. 1 . 
     Referring now to the left had sides of  FIGS. 1 to 5  of the drawings, these show a press head  50  into which the studs are inserted for subsequent placement and fixing during a press operation. To the left of breech exit aperture  35  there is a main block  50  having substantial walls and central circular aperture  52 . Within the aperture  52  is a short cylinder  54  (cylindrical press member), rotatable about a horizontal axis at right angles to the axis of piston/cylinder  40  and set within the main block  50 . A segmental slot in cylinder  54  allows connection of the cylinder via a connector  59  and pivot  57  to one end of a piston  58  forming part of a pneumatic piston cylinder device  60  having pressure/exhaust ports  64 ,  64 . 
     Within the cylinder  54  is an arrangement for receiving and holding a fastener. In the illustrated embodiment, the arrangement for receiving and holding includes a radial bore into which is fixed a bush  56  having a central bore forming an entry chamber into which the shank of the stud can pass, as can be seen in  FIG. 1 . The head  18  of the stud protrudes from the central bore and lies against shoulders  58  of the bush  56 . 
     The cylinder  54  is rotatable in aperture  52 , by advancing or retracting piston  58  through 90° between a position in which the bore of bush  56  is horizontal, opening sideways of the press ( FIG. 1 , defined by abutment between part of cylinder  54  and part of block  50 ), and one in which it is vertical, opening in the pressing direction ( FIG. 1 , defined by the abutment of bush  56  against the lower part of block  50 ). When horizontal,  FIG. 2 , the bore of the plug  56  is aligned with the axis of tapering apertures  34 , 35  at the end of the breech  20 , so a stud  14  can be pushed through the aperture  34  and into the bore  56 . Once this has occurred, the piston  58  may be retracted to rotate the cylinder  54  to a position in which the bore of the bush  56  is vertical, and the head  18  of the stud protrudes below the bush  56 , as shown in  FIG. 1 . With the cylinder  54  in this position, the entire assembly shown in  FIGS. 1 to 5  is moved downwards (arrow P) to move stud  14  down to press the head  18  partly through an aperture in a sheet of metal for a forming operation. A die on the underside of the sheet, enables the head of stud  14  to be attached to the metal sheet by known techniques, such as that described in U.S. Pat. Nos. 3,938,239 and 3,018,257. During this process, the stud head  18  is deformed into the die below the sheet under pressure applied by the shoulders  58  of the bush  56 . 
     The cylinder  54  is supported across substantially it&#39;s full width in the aperture  52  in the block  50  as the cylinder  54  is rotated and during the pressing operation, as can be seen from  FIG. 6 . 
     As noted above, the cylinder  54  must be reciprocated between the two positions exactly 90° apart and this precision would be difficult to achieve by merely relying on the end positions of the piston within pneumatic cylinder  60 . Accurate positioning can be achieved by means shown in  FIG. 5 . The cylinder  54  has at each end an area milled away to leave an arcuate portion  66  standing proud. The radially extending ends  68 ,  70  of the arcuate portion  66  visible in  FIG. 5  contact a wall  72  protruding from the main block  50  which acts as a stop to limit the movement of precisely 90°. Adjacent the part of the wall  72  which acts as a stop for the end  70 , there is a proximity sensor  74  for sensing when the arcuate portion  66  is firmly in contact with the wall  72 . If there is no such contact, then the cylinder  54  is not in a position where the bush  56  and stud  14  are accurately vertical, and lowering the assembly to fix the stud  14  in the sheet can be inhibited. 
       FIG. 8  indicates that operation of the stud delivery system and a cold forming press (not shown) can be controlled by a PC  76  which supplies control signals to appropriate electrically controlled valves connected in the pneumatic lines leading to pressure/exhaust ports  42 , 44  of the cylinder  40  and pressure/exhaust port  62 , 64  of the cylinder  70 , at appropriate times in the operating cycle. The PC  76  has input lines for receiving signals from the proximity sensor  74  and microswitch  46 , and an output line  78  to supply an inhibit signal to the main control of the mechanism for operating the press if the rotary cylinder  54  is not in the correct position for the stud to be inserted and fixed efficiently and safely into the sheet. 
     In operation, starting from the position shown in  FIG. 2 , the pneumatic cylinder  40  is operated to push the stud  14  shank first into the bush  56  until the stud head  18  clears the members  24 , 26  and abuts the shoulder  58 . The stud shank  18  is gripped in the bush  56 , e.g. by a ball and spring mechanism. Piston  60  is then actuated to rotate member  54  to align the stud  14  vertically, as in  FIG. 1 . The press head  50  is then actuated to affix the stud to a metal sheet which is being worked on. While the press head is operating, a new stud is delivered with the breech  20 . 
     It will be appreciated that the apparatus can be operated with different stud lengths, if the breech  20  and the bore of bush  56  are designed to receive the maximum desired stud length. For different size studs, the bush  56  and pivot members  24 , 26  can be changed.