Abstract:
The present invention relates to a quick release mount for a suction cup and a locking member for releasably locking the suction cup within a housing. The suction cup mount includes a bayonet coupling which is attached to the suction cup. The bayonet coupling is received within a space located within the housing. The housing further includes a pair of semi-circular flanges for securing the bayonet coupling within the space. The locking member selectively engages the bayonet coupling when the bayonet coupling is moved from an unlocked position to a locked position. The housing also includes a button coupled to the locking member that can release the locking member from engagement with the bayonet coupling and permit unlocking of the bayonet coupling from the housing.

Description:
This application claims the benefit of U.S. Provisional Application No. 60/027,421, filed Oct. 8, 1996. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates generally to suction cups and, more particularly, to a suction cup having a quick release mount. 
     Suction cups are used in a wide variety of manufacturing environments. Typically, they are used to hold and position a workpiece during transfer, assembly or machining operations. 
     Typically, suction cups are mounted to a housing that is attached to a robot arm or a workholding arm of a tooling machine. The suction cups need to be in an reproducible position to ensure that the workpiece is properly positioned during the machining or assembly process. To ensure that the workpiece is held in the proper location, the suction cup housing is usually secured in fixed position relative to the robot or workholding arm by a clamping mechanism. The suction cups occasionally need to be replaced with suction cups of a different shape to accommodate the contour of the workpiece. In addition, the suction cups frequently either break or need to be replaced due to wear. It is desirable that, the exchange or replacement be rapidly accomplished and that it not change the orientation of the suction cup housing relative to the arm. It is also desirable to incorporate a means for releasably locking the suction cup within the housing. 
     Therefore, it is desirable to provide a quick release suction cup mount that permits a user to easily exchange or replace suction cups without altering the orientation of the suction cup housing relative to the robot or workholding arm that it is associated with. In addition, it is further desirable to provide a releasable locking mechanism which further secures the suction cup mount to the housing. 
     SUMMARY OF THE INVENTION 
     In general terms, this invention provides a unique mounting mechanism and a locking feature that permits a suction cup to be rapidly mounted and locked in position to a housing and to be released from the housing rapidly. 
     Preferably, the suction cup is mounted to a bayonet coupling that is received within a space in a housing. The space is defined by a pair of semi-circular flanges mounted on a rim of the housing. The bayonet coupling fits within the rim and has a pair of ears that are received under the semi-circular flanges when the bayonet coupling is placed in the space and rotated 90 degrees from an unsecured position to a secured position. When the bayonet coupling ears are received under the semi-circular flanges, a locking member is biased into a recessed portion located in at least one of the ears and the locking member locks the bayonet coupling within the space in the housing. A button is coupled to the locking member and permits it to be moved out of engagement with the recess in the bayonet coupling thus allowing the rapid unlocking of the bayonet coupling from the housing in order to exchange or remove the suction cup. A central passage extends through the housing, bayonet coupling, and the suction cup to provide a vacuum through the suction cup. The vacuum secures the workpiece to the suction cup. 
     These and other features and advantages of this invention will become more apparent to those skilled in the art from the following detailed description of the presently preferred embodiment. The drawings that accompany the detailed description can be described as follows. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a cross-sectional side view of a quick release suction cup designed according to this invention; 
     FIG. 2 is a top plan view of the bayonet coupling shown in FIG. 1; 
     FIG. 3 is a cross-sectional side view of the bayonet coupling shown in FIG. 2 along lines  3 — 3 ; 
     FIG. 4 is a side perspective bottom view of the housing shown in FIG. 1; 
     FIG. 5 is a side view of a quick release suction cup designed according to this invention mounted to a robot arm; 
     FIG. 6 is an exploded side view of the venturi, the housing, and the bayonet coupling shown in FIG. 5; 
     FIG. 7A is an exploded side perspective bottom view of the housing shown in FIG. 6; 
     FIG. 7B shows locking pin structure; 
     FIG. 8 is a cross-sectional side view of the bayonet coupling shown in FIG. 6 along lines  8 — 8 ; 
     FIG. 9 is an exploded side perspective view of the venturi shown in FIG.  6  and an annular seal; and 
     FIG. 10 is a top plan view of the venturi shown in FIG.  6 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 shows a quick release suction cup  10  including a suction cup  12  mounted to a bushing  14 . The bushing  14  is fixed to a bayonet coupling  16 . A housing  18  has a space  20  for receiving the bayonet coupling  16 . A cylindrical plunger  22  having a rim  24  is received within the housing  18 . An inner wall  26 , an upper rim  28 , an outer wall  29 , and the rim  24  define a cylindrical spring space  30  within the housing  18 . A spring  32  encircles the cylindrical plunger  26  and is trapped within the spring space  30 . The spring  32  biases the cylindrical plunger  22  into the space  20 . An annular seal  34  is located between the bayonet coupling  16  and the cylindrical plunger  22 . Most preferably the annular seal  34  is an O-ring. 
     A central passage  36  extends through the housing  18 , the cylindrical plunger  22 , the annular seal  34 , the bayonet coupling  16 , and the suction cup  12 . The central passage  36  has an upper end  38  and a lower end  40 . A connector hose  42  and a connector  44  couple the upper end  38  of the central passage  36  to a vacuum source  46 . The vacuum source  46  is of a conventional type well known in the art. 
     A clamping stem  48  is mounted to the housing  18 . The clamping stem  48  is specifically shaped to be accommodated in a variety of clamps (not shown) that are well known in the art. The location and shape of the clamping stem  48  allows the housing  18  to be clamped in any position relative to the clamp. Additionally, the clamping stem  48  has the advantage of permitting the suction cup  12  and bayonet coupling  16  to be removed from the housing  18  while maintaining the positioning of the housing  18  relative to the clamp. 
     FIG. 2 is a top plan view of the bayonet coupling  16  which shows a pair of ears  50 . An annular groove  52  in the bayonet coupling  16  receives the annular seal  34 . The annular groove  52  and the annular seal  34  encircle the central passage  36 . 
     FIG. 3 shows bushing  14  is secured to a nipple portion  54  of the bayonet coupling  16 . The suction cup  12  is adhesively connected to the bushing  14 . Optionally, the nipple portion  54  may include a set of external or internal threads (not shown) for securing the suction cup  12  to the bayonet coupling  16 . The bushing  14  would be unnecessary if the nipple portion  54  includes a set of threads. The annular groove  52  includes an undercut  56  to provide a better seal when an O-ring is used as the annular seal  34 . 
     FIG. 4 is a side perspective bottom view of the housing  18 . A lower rim  58  extends from a housing base  60 . The rim  24  of the cylindrical plunger  22  extends beyond the housing base  60  into the space  20  due to the bias of spring  32 . A pair of semi-circular flanges  62  are mounted opposite each other to the lower rim  58 . The lower rim  58  and the semi-circular flanges  62  define the space  20 . 
     In use of this embodiment, the bayonet coupling  16  with the attached suction cup  12  and annular seal  34  is initially aligned with the ears  50  non-aligned to the semi-circular flanges  62 . The bayonet coupling  16  is then inserted into the space  20  until the bayonet coupling  16  is flush against the housing base  60 , thus moving the rim  24  to a position below flush with the housing base  60 . The bayonet coupling  16  is then rotated ninety degrees from that unsecured position to a secured position wherein the ears  50  are aligned with the semi-circular flanges  62 . In this position the bayonet coupling  16  is at a secured position relative to the housing  18 . The bias of the spring  32  against the rim  24 , of the cylindrical plunger  22  urges the plunger  22  into engagement with the annular seal  34  and additionally secures the bayonet coupling  16  within the space  20 . The annular seal  34  also ensures that the central passage  36  is sealed between the lower end  40  and the upper end  38 . The bayonet coupling  16  can be rapidly removed from the space  20  by rotating the bayonet coupling  16  ninety degrees to move the ears  50  out of alignment with the semi-circular flanges  62 . An additional advantage of the bayonet coupling  16  with an annular groove  52  is that it prevents damage to the annular seal  34  when the bayonet coupling  16  is moved between the unsecured and secured positions. 
     When the bayonet coupling  16  is in the secured position, application of a vacuum through the vacuum source  46  will produce a vacuum at the lower end  40  of the central passage  36 . Thus, a workpiece (not shown) will remain secured to the suction cup  12  so long as the vacuum is maintained. Additionally, as will be understood by one of ordinary skill in the art, the quick release suction cup could be utilized without a central passage  36 . In such an embodiment, the workpiece would be secured to the suction cup  12  by utilizing the natural vacuum that is created when a sealed suction cup is flattened against a surface. 
     In FIG. 5, a side view of a preferred second embodiment of the quick release suction cup is shown generally at  64 . A housing  66  includes a slot  68  for receiving a button  70 . Slot  68  allows button  70  to move upwardly from the illustrated position. A rim  72  encircles the housing  66  and supports a pair of semi-circular flanges  74 . A clamping stem  76  extends from the housing  66 . As shown in FIG. 7A, clamping stem  76  receives a clamp  200 , with the clamp  200  being fixed to a tool such as a moving arm  202 . The clamp  200  and the moving arm  202  are shown somewhat schematically as they are known. 
     A clamping plate  78  and a pair of bolts  80  secure the housing  66  to a sliding bushing  82 . The sliding bushing  82  is received on a post  84 . Post  84  is secured to a robot arm mount  86 . Robot arm mount  86  is known in the art. A spring  88  biases the clamping plate  78  away from the robot arm mount  86 . A venturi  92  having an outlet hole  94  can optionally be accommodated between the clamping plate  78  and the housing  66  to provide a venturi effect vacuum as described below. 
     FIG. 6 is an exploded side view of the venturi  92 , the housing  66 , and the bayonet coupling  96  shown in FIG.  5 . The venturi  92  and the housing  66  both include a pair of holes  98  and  100 , respectively, for receiving the bolts  80  that secure the clamping plate  78  to the venturi  92  and the housing  66 . A plug  102  is located in the venturi  92 . A central passage  104  extends through the housing  66 . The bayonet coupling  96  includes a pair of ears  106  opposite each other. Each of the ears  106  includes a recess  108 . An annular groove  110  encircles a central passage  112  that extends through the bayonet coupling  96 . An O-ring (not shown) is accommodated in the annular groove  110 . As will be appreciated by one of ordinary skill in the art, another type of annular seal other than an O-ring could be utilized. 
     FIG. 7A is an exploded bottom view of the housing  66 . The rim  72 , a housing base  75 , and the semi-circular flanges define a space  73  for receiving the bayonet coupling  96 . A pin hole  114  in the housing  66  accommodates a spring  116  and a pin  118 . The pin  118  includes a recess  120  for receiving the spring  116  and a through hole  122  perpendicular to the longitudinal axis of the pin  118 . A cut out  124  in one of the semi-circular flanges  74  allows the spring  116  and the pin  118  to be initially inserted into pin hole  114 . A lock pin  126  extends through the button  70  and into through hole  122  to couple the button  70  to the pin  118 . The pin  118  in combination with the spring  116  serves as a locking member as discussed below. 
     FIG. 8 is a cross-sectional side view of the bayonet coupling  96  shown in FIG. 6 along lines  8 — 8 . The annular groove  110  includes an undercut  128  to provide a better seal between the bayonet coupling  96  and the housing  66  when an O-ring is used as the annular seal (not shown). A nipple portion  130  of the bayonet coupling  96  includes a set of threads  132 . The suction cup  12  (not shown) is secured to the bayonet coupling  96  by the threads  132 . As will be understood by one of ordinary skill in the art, the suction cup  12  might also be secured to the nipple portion  130 , in the absence of the threads  132 , using a conventional adhesive. 
     In FIG. 9, an exploded side perspective view of the venturi  92  and an annular seal  134  is shown. The venturi  92  includes a plug hole  136 , a bypass hole  138  and a venturi cartridge hole  140 . A plug spring  142  and a bypass valve  144  are secured within the plug hole  136  by the plug  102 . A venturi cartridge  146  is accommodated in the venturi cartridge hole  140 . 
     FIG. 10 is a top plan view of the venturi  92  shown in FIG.  9 . The venturi cartridge hole  140  extends through the venturi  92  and communicates with the outlet hole  94 . The plug hole  136  is oriented perpendicularly to the venturi cartridge hole  140  and also communicates with the outlet hole  94 . The bypass hole  138  is oriented parallel to the venturi cartridge hole  140  and perpendicular to the plug hole  136 . The bypass hole  138  communicates with the plug hole  136 . The venturi cartridge hole  140  is in communication with the central passage  104  of the housing  66  and the central passage  112  of the bayonet coupling  96 . The venturi  92  operates in a conventional fashion as is well known by those of ordinary skill in the art and its design forms no portion of the novel features of this invention. Briefly, a flow of a fluid or a gas is passed through the venturi cartridge  146  and the outlet hole  94 . A venturi effect vacuum is produced within central passages  104  and  112 , thus enabling the suction cup  12  to secure a workpiece. Discontinuing the flow through the venturi cartridge  146  and subsequently introducing a flow through bypass hole  138  forces bypass valve  144  away from plug  102  and closes outlet  94 , thus forcing the flow through central passages  104  and  112 . The flow through central passages  104  and  112  forces the workpiece off the suction cup  12 . 
     In use of this embodiment of the quick release suction cup, the bayonet coupling  96  is initially oriented with the ears  106  positioned non-aligned to the semi-circular flanges  74 . FIGS. 7A and 7B show the locking feature of pin  118 . The pin  118  extends beyond the housing base  75  and into space  73 . As the bayonet coupling  96  is moved into space  73  until it is flush with housing base  75 , the bayonet coupling  96  forces pin  118  into pin hole  114  until pin  118  is flush with the housing base  75 . This is the unlocked position. Rotation of the bayonet coupling  96  ninety degrees aligns the ears  106  with the semi-circular flanges  74  and permits pin  118  to be biased by spring  116  into one of the recess  108  in the ears  106  of the bayonet coupling  96 , thus locking the bayonet coupling  96  in a locked position in the housing  66 . Moving button  70  in slot  68 , upwardly as shown in FIG. 5, or away from housing base  75  withdraws pin  118  from recess  108 . Subsequent rotation of the bayonet coupling  96  ninety degrees enables removal of the bayonet coupling  96  from the housing  66 . 
     As discussed above, the venturi  92  is an optional means for producing a vacuum within central passages  104  and  112 . If the venturi  92  is not utilized, a vacuum can be produced within the central passages  104  and  112  by means of a conventional connection connecting the central passage  104  in the housing  66  to a vacuum source. 
     This embodiment also includes the clamping stem  76 . The clamping stem  76  permits the housing  66  to be held at any position relative to a clamp (not shown) of the type known in the art. In a situation where the clamping plate  78  is not used to secure the housing  66  to a post  84 , the clamping stem  76  is used to secure the housing  66  to a clamp. The clamping stem  76  can be used with or without the venturi  92 . As discussed above, the clamping stem  76  permits the bayonet coupling  96  to be moved between the unsecured and the secured locked positions within the housing  66  while maintaining the position of the housing  66  relative to the clamp. This allows the suction cup  12  to be removed and replaced, while maintaining a fixed position in space. 
     The foregoing description is exemplary rather than limiting in nature. Variations and modifications to the disclosed embodiment may become apparent to those skilled in the art and do come within the scope of this invention. Accordingly, the scope of legal protection afforded this invention can only be determined by studying the following claims.