Abstract:
A quick disconnect device having a locking feature for securing the quick disconnect device in a lock position is provided for connecting tooling attachments to the boom of an electromechanical feeder used with pick and place operations. The locking action utilizes a cam and follower arrangement and is provided by a detent in a lock position of the cam contour. The detent retains the cam follower in the lock position and prevents the cam follower from becoming unintentionally released, preventing the tooling attachment from becoming loose or disconnected from the boom.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to a quick disconnect device for electromechanical devices which are used to move parts between two fixed points, such as to load and unload stamping press. More specifically, this invention relates to a quick disconnect device having a detent which secure the quick disconnect device in a lock position when the quick disconnect device has mechanically connected an attachment to the boom of the electromechanical device. 
     2. Description of the Prior Art 
     Electromechanical devices, or feeds, are extensively used with stamping presses, automated assembly lines, and other similar pick and place operations. Feeders typically include an electromechanical drive system and one or more attached drive arms. Each arm has one or more booms mounted to its ambulatory end to which tooling attachments can be connected for performing the various pick and place operations. The feeders are required to operate at high speed to ensure efficient operation and with precision to prevent damage to the feeder, the tooling attachments, cooperating equipment, and the products of the operation. 
     Another requirement of such feeders is the need for interchangability between various tooling attachments. To reduce machine downtime, it is necessary that the changeover between tooling attachments be conducted quickly. Therefore, quick disconnect devices have been developed to quickly connect and disconnect attachments with the boom of a feeder. 
     A disadvantage of quick disconnect devices known thus far is their susceptibility to becoming disengaged during operation as a result of the vibrations and rapid motions of the feeder arm. An undesirable result is that the tooling attachment becomes loose from the boom. Wear can also occur within the quick disconnect device which can lead to further loosening of the tooling attachment and ultimately the replacement of the quick disconnect device. Further consequences are the loss in accuracy of placement which produces wear of cooperating equipment such as dies and molds, the damage or destruction of the tooling attachment when it becomes overly loose or entirely disconnected, and the accompanying downtime and costly repairs on the assembly line. 
     Therefore, what is needed is a quick disconnect device that can withstand the adverse vibrational environment of feeders by having some provision that prevents the loosening of a tooling attachment to the boom and, therefore, extends the efficiency, usefulness and life of the tooling attachments and the cooperating equipment. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a quick disconnect device for quickly connecting and disconnecting tooling attachments to feeders which are used to move parts between two fixed points. 
     It is a further object of this invention that such quick disconnect device provide a detent for positively securing the quick disconnect device in a lock position when connecting a tooling attachment to the boom of a feeder. 
     In accordance with the preferred embodiment of this invention, these and other objects and advantages are accomplished as follows. 
     According to the prevent invention there is provided a locking quick disconnect device which is suitable for connecting and disconnecting tooling attachments to the boom of a feeder used to move parts between two fixed points. The locking quick disconnect device has a first member that mounts to the boom and a second member that mounts to the tooling attachment. The second member nests within the first member. A cam arrangement is provided through which a rod extends into the first member through an opening in the first member. The cam arrangement is operated by a lever which when rotated translates the rod between a disengaged position when the rod is retracted and disengaged with the second member, and an engaged position when the rod is extended and, therefore, engaged with the second member. The cam arrangement includes at least one cam follower and cam track combination, the cam track having a lock position which corresponds to the rod being extended and engaged with the second member, and a release position which corresponds to the rod being retracted and disengaged from the second member. 
     According to a preferred aspect of this invention, located at the lock position of the cam track is a detent which acts to secure the cam follower in the lock position of the cam track. The detent is a notch formed in the contour of the cam track and is sized to closely receive the cam&#39;s follower. 
     A significant advantage of the disclosed invention is that the detent prevents the cam follower from being dislodged from the lock position of the cam track preventing the release of the second member from the first member and, therefore, the tooling attachment from the boom. 
     Other objects and advantages of this invention will be better appreciated after a reading of the detailed description thereof taken in conjunction with the appended drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a locking quick disconnect device mounted to a boom and connecting a tooling attachment to the boom in accordance with a preferred embodiment of this invention; 
     FIG. 2 is a cross-sectional side view of a locking quick disconnect device in accordance with a preferred embodiment of this invention; 
     FIG. 3 is an exploded side view of the housing member and cam arrangement as shown in FIG. 2; 
     FIG. 4 is a partial cross-sectional side view of a locking quick disconnect device in a release position in accordance with a preferred embodiment of this invention; 
     FIG. 5 is a partial cross-sectional side view of a locking quick disconnect device in a lock position in accordance with a preferred embodiment of this invention; and 
     FIG. 6 is a detailed side view of a cam track in accordance with a preferred embodiment of this invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In a preferred embodiment of this invention, a locking quick disconnect device 10, as shown in FIG. 1, is mounted to a boom 12. The locking quick disconnect device 10 is shown connecting a tooling attachment 14 to the boom 12, by which the tooling attachment 14 and boom 12 are allowed to cooperate to perform pick and place operations when driven by a conventional feeder. 
     As shown in FIGS. 2 and 3, the preferred locking quick disconnect device 10 includes a housing member 11, a locking member 13, and a cam arrangement 15. The housing member 11 has two oppositely disposed side walls 33a and 33b, a first end wall 34, and a longitudinal wall 35. The longitudinal wall 35 is rigidly attached to the boom 12. The locking member 13 is nested in the housing member 11 and is rigidly mounted to the tooling attachment 14. The cam arrangment 15 is mounted to the first end wall 34 of the housing member 11. 
     An opening 16 is provided in the first end wall 34 of the housing member 11 to which the cam arrangment 15 is mounted. Adjacent to an oppositely disposed second end of the housing member 11 is a transverse member 32 which extends between and connects the side walls 33a and 33b. An aperture 17 is provided in an apertured end 36 of the locking member 13 adjacent to the opening 16 of the housing member 11, and is substantially coaxial therewith. The locking member 13 is further provided with a receiving slot 37 in an end oppositely disposed from the apertured end 36 which is sized to receive the transverse member 32. 
     The cam arrangement 15 includes an annular housing member 18, an annular cam member 19, a rod member 21, a carrier sleeve 22, and lever 20. The annular housing member 18 is positioned coaxially with the opening 16 and is circumferentially enclosed by the annular cam member 19. The rod member 21 is coaxially disposed through the annular housing member 18. The carrier sleeve 22 is disposed between the rod member 21 and the annular housing member 18. The lever 20 is rigidly attached to the annular cam member 19 and is oriented substantially perpendicular to the longitudinal axis of the annular cam member 19. 
     An engaging end 23 of the member 21 extends through the annular housing member 18 and the opening 16 while an oppositely disposed threaded end 24 extends through the carrier sleeve 22. The threaded end 24 of the rod member 21 has a smaller diameter than the engaging end 23. The carrier sleeve 22 is a retained at one end by the differing diameters of the engaging end 23 and the threaded end 24 and at its other oppositely disposed end by a nut 25. Other conventional means for retaining the carrier sleeve 22 may also be used, such as a cotter key or a C-spring. 
     The annular housing member 18 has a pair of diametrically opposed slotted openings 26a and 26b that are longitudinally oriented in the housing wall. Cam followers 27a and 27b are mounted diametrically opposed on the carrier sleeve 22 and are located such that they extend through the slotted openings 26a and 26b and engage diametrically opposed cam tracks 28a and 28b in the annular cam member 19. Although two cam track and cam follower arrangements are shown and preferred because they provide for balanced loading of the rod member 21, it is apparent that only cam track and cam follower arrangement is sufficient to provide for translation of the rod member 21. 
     Each of the cam tracks 28a and 28b has a release position 29a and 29b and a lock position 30a and 30b. Arcuate notches or detents 31a and 31b are disposed at the lock position 30a and 30b of each cam track 28a and 28b and are sized to closely receive the cam followers 27a and 27b. The cam tracks 28a and 28b are contoured such that when the lever 20 rotates the annular cam member 19 causing the cam followers 27a and 27b to traverse the cam tracks 28a and 28b, the slotted openings 26a and 26b force the cam followers 27a and 27b to simultaneously translate in a longitudinal direction. When the cam followers 27a and 27b engage the arcuate notches 31a and 31b, the cam followers 27a and 27b are secured in their respective lock positions 30a and 30b. Engagement of the cam followers 27a and 27b with the arcuate notches 31a and 31b is promoted by the reaction force from the rod member 21 being forced against the locking member 13. The cam followers 27a and 27b will not disengage from the arcuate notches 31a and 31b without a deliberately applied external force being exerted upon the cam followers 27a and 27b through the lever 20. 
     Because the cam followers 27a and 27b are mounted to the carrier sleeve 22, the carrier sleeve 22 is also translated in a longitudinal direction. Further, since the carrier sleeve 22 is coupled with the rod member 21, the rod member 21 also translates in a longitudinal direction. 
     As shown in FIG. 4, when the cam followers 27a and 27b are in the release positions 29a and 29b of the cam tracks 28a and 28b, the rod member 21 is retracted. The translational motion of the cam followers 27a and 27b retracts the rod member 21 to disengage from the aperture 17. When the rod member 21 disengages from the aperture 17, the tooling attachment 14 is disconnected from the boom 12 and is free to be removed and replaced with a second tooling attachment. 
     As shown in FIG. 5, when the cam followers 27a and 27b are in the lock positions 30a and 30b of the cam tracks 28a and 28b, the rod member 21 is extended. The translational motion of the cam followers extends the rod member to engage the aperture 17. When the rod member 21 engages the aperture, the tooling attachment 14 is securely connected to the boom 12. 
     FIG. 6 shows the annular cam member 19 in detail. The cam track 28b having the arcuate notch 31b disposed at the lock position 30b is shown. For illustrateive purposes only, a single cam track and corresponding features have been shown. 
     In the preferred embodiment, a significant advantage of the locking quick disconnect device 10 is the ability of the arcuate notches or detents 31a and 31b to prevent disengagement of the cam followers 27a and 27b from the lock positions 30a and 30b without a deliberately applied force to the lever 20. Thus, the tooling attachment 14 cannot be unintentionally disconnected from the boom 12 and the integrity of the connection will withstand the vibration and motion induced upon the boom 12 by the feeder and the pick and place operation. 
     While the invention has been described in terms of a perferred embodiment, it is apparent that other forms could be adopted by one skilled in the art. Examples are the number of cam follower and track combinations and the rearrangement of the locking quick disconnect members with respect to the tooling attachment, boom, and each other. Accordingly, the scope of the invention is to be limited only by the following claims.