Abstract:
The invention is directed to a method and apparatus for gripping DIP components automatically without the need for shutting down the machine to change the tooling assembly when handling components which differ in width. Two sets of fingers are provided, with one set inside the other, such that engagement of the inner pair with a wide component causes automatic retraction of them sufficiently for gripping of the component by the outer pair. In the absence of a component, the inner pair of fingers is automatically extended for subsequent component handling.

Description:
PRIOR ART CROSS-REFERENCE 
     U.S. Pat. No. 4,500,032--Ackerman--METHOD AN APPARATUS FOR PROPER REGISTRATION OF MATING PARTS, issued Feb. 19, 1985. 
     BACKGROUND OF THE INVENTION 
     The invention is in the field of article handling, particularly the pick-up of DIP components and insertion of the leads thereof into corresponding holes of a circuit board. 
     Presently, mounting of components which differ in a particular dimension such as body width requires a different tooling assembly for each size of component. Thus, operation of more than one tooling assembly at a time, or machine &#34;down time&#34; for a tooling change, is required in order to switch back and forth between components differing in width. 
     It is an object of this invention to provide for automatic changing back and forth between gripper fingers of a tooling assembly according to variations in a particular dimension of components, without interrupting the component handling process. 
     Further, it is an object of this invention to minimize the footprint of a tooling assembly which automatically selects and uses different sets of gripping fingers according to differences in a particular dimension from one component to the next. 
     Additionally, it is an object of the invention to provide a tooling assembly which grips DIP components with 0.300 inch and 0.600 inch CTC lead spacings by different pairs of gripping fingers, selectively and automatically, according to body widths of the components. 
     These and other objects will become apparent from the following detailed description of the invention 
     BRIEF SUMMARY OF THE INVENTION 
     The invention is directed to a method and apparatus for gripping DIP components automatically without the need for shutting down the machine to change the tooling assembly when handling components which differ in width. Two sets of fingers are provided, with one set inside the other, such that engagement of the inner pair with a wide component causes automatic retraction of them sufficiently for gripping of the component by the outer pair. In the absence of a component, the inner pair of fingers is automatically extended for subsequent component handling. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIGS. 1 and 2 are front elevation illustrating, respectively, the tooling assembly gripping small and large components. 
     FIG. 3 is a side elevation of the replaceable tooling assembly. 
     FIG. 4 is a right side elevation of the device of FIG. 3. 
     FIG. 5 is a bottom plane view of the device of FIG. 3. 
     FIG. 6 is a top plane view of the device of FIG. 3. 
     FIG. 7 is a front side elevation of a support bracket for the tooling assembly illustrating the offset pivot and support points for the linkages of the tooling assembly. 
     FIGS. 8-11 are, respectively, front elevation, left and right side elevations, and bottom plane view of one-half of the split housing and guide for the tooling assembly. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In a preferred embodiment of the invention, the support bracket 10 will be bolted or otherwise attached to a robot hand such as that disclosed in U.S. Pat. No. 4,500,032 as a replacement for the gripper assembly of that hand while retaining the pusher bar thereof, and the disclosure of this patent is incorporated herein by reference. 
     The tooling assembly of the instant invention comprises two separate housing and guide halves 20, 22 which also are supported by the robot hand or the like to which bracket 10 is attached. Referring to FIGS. 8-11, it may be seen that bracket 20 has slots 25 and 26 at opposite ends thereof and offset relative to each other, with slot 25 acting as a guide for an inside finger 40 and slot 26 acting as a guide for outside finger 50. Housing half 22 is similar to housing half 20 and provides guide slots for inside finger 42 and outside finger 52. As seen in FIGS. 3-5, pins 12 and 14 have parallel, offset axes and provide pivotal support, respectively, for links 30 and 34 by support bracket 10. Each link 30 and 34 has a pair of slots near the outer ends thereof for sliding reception of a rod. 
     As seen in FIGS. 1 and 2, the slot on the left end of link 30 receives a actuating rod 51 which extends through slot 26 of housing half 20 of slot 31 in the right hand end of link 30 receives actuating rod 43 of inside finger 42, with actuating rod 43 fitting through guide slot 24 of housing half 22. On the opposite end (right hand side of FIG. 4) of the tooling assembly, pin 14 supports link 34 which is slidably connected to inside finger 40 and outside finger 52. Compression springs 28 are provided in inside fingers 40 and 42 in order to urge these inner fingers to the extended position of FIG. 1. 
     Thus, with inner finger 42 in the extended position of FIG. 1, the linkage 30 will ensure that the opposite outer finger 50 is in the illustrated retracted position. As will be appreciated, the other inner finger 40 is linked to the opposite outer finger 52 in the same manner. Thus, upon overcoming the bias of springs 28, the inner fingers 40, 42 are pushed upwardly such that outer fingers 50, 52 are extended to the position of FIG. 2. 
     In operation, this automatic interchanging of positions between outer fingers 50, 52 and inner fingers 40, 42 provides automatic selection of a spacing between a gripping fingers according to a particular dimension of a component to be picked up, e.g., a DIP component. 
     Assuming that the tooling assembly is empty as illustrated in FIG. 3, the robot hand or other means of supporting the tooling assembly is manipulated to raise the empty tooling assembly and position it above a component supply, such as a component support rail 70 with component 2 thereon as illustrated in FIG. 1. The tooling assembly halves 20 and 22 have been properly separated from each other along a mid-plane sufficiently for pick-up of a component such as in FIG. 1. 
     Thereafter, the tooling assembly is lowered to the vertical position of FIG. 1 and closed upon the leads of the component and the robot hand is raised to transport and position the component relative to the holes of a circuit board into which the leads 4 of the component 2 are to be inserted. Then, the robot hand is lowered and a pusher bar 60 of the robot hand, which extends between halves 20 and 22, is actuated to push the component and effect insertion of the leads into the holes of the circuit board while the leads are guided or &#34;funneled&#34; by grooves on the inside of the fingers 40 and 42. At this time, the leads that protrude through the underside of the circuit board are normally clinched thereto. 
     Thereafter, the halves 20 and 22 are spread apart sufficiently to open the fingers 40 and 42 clear of the leads of the component and the robot hand is then retracted and moved to another supply station. If the next component to be picked up has a body of sufficient width, as illustrated in FIG. 2, the inner fingers 40 and 42 will engage the top surface thereof during lowering of the hand for the pick-up function. Thus, inner fingers 40 and 42 will retract against the compression of springs 28 and, through pivoting of links 30 and 34, outer fingers 50 and 52 will be extended to the position of FIG. 2. 
     Thereafter, the halves 20 and 22 are closed sufficiently to engage fingers 50 and 52 with the leads of the component and the previously described transport and insertion steps will be performed. However, it should be noted that as the pusher bar 60 is extended, the inner fingers 40 and 42 will remain in touch with the component which is being inserted and, in concert therewith, outer fingers 50 and 52 will be retracted. 
     Although the instant invention has been described with relation to DIP components, it is contemplated herein that other types of components, such as axial lead components whose leads have already been formed, could be handled in much the same way as disclosed herein, with modifications to the shapes of the fingers. It is further contemplated that more than two pairs of fingers could be utilized such that a broader range of component body widths may be handled without the time consuming step of shutting down the machine and interchanging the fingers to handle a component. 
     As may be appreciated, the instant invention allows several different sizes of components to be mounted by the same insertion head, thus eliminating the need for a separate run of circuit boards past an insertion station for each different size of DIP or the like to be inserted. 
     Among the objects made apparent from the preceding description, certain changes may be made in carrying out the above method and in the construction set forth without departing from the scope of the invention, and it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 
     It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention, which, as a matter of language, might be said to fall therebetween.