Abstract:
An improved collet crimping head used with an existing single lane capping apparatus and collet chuck for gripping, installing and crimping pharmaceutical over-caps and the like during the automated high-volume filling and capping process. The collet crimping head is a unitary member formed with a lower cap crimping section and an upper mounting collar for attachment to a chuck of said automatic capping assembly. The lower cap crimping section has an inwardly directed and constrictable crimping collar for crimping and sealing aluminum hoods of said over-caps onto the necks of containers. The collet crimping head has a slim profile for low inertia, and it incorporates a simplified design for increased durability and reliability, lower manufacturing cost, and greater ease of handling.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is based on U.S. Provisional Patent Application 60/083,899 entitled “COLLET CRIMPING HEAD”, filed May 1, 1998, and is a continuation-in-part of U.S. patent application Ser. No. 09/222,475 entitled “QUICK-CHANGE COLLET CHUCK”, filed Dec. 29, 1998, now U.S. Pat. No. 6,170,232. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to automated machinery for crimping caps onto containers and, more particularly, to a collet crimping head for gripping, installing and crimping container caps onto containers during an automated high-volume filling and capping process. 
     2. Description of the Background 
     The filling and capping process generally entails supplying containers along a conveyor, automatically filling them at a filling station, and automatically capping them at a capping station. Various testing and control functions may be performed along the way, e.g., testing and control of fill volume, conveyor velocity, etc. The apparatus which performs the process must be capable of accommodating a wide variety of containers and caps (both caps and containers may vary in size and shape), and this is accomplished by a universal chuck which allows quick and easy grasping and manipulation of different cap sizes. 
     In U.S. patent application Ser. 09/222,475 entitled “QUICK-CHANGE COLLET CHUCK”, filed Dec. 29, 1998, the inventor herein explained that many caps are intended for screw-insertion onto containers, and a variety of automated collet chucks exist for positioning and torquing of such caps. The above-referenced application describes how a low-inertia collet-type chuck which has proven itself far superior to conventional Donut Chucks and the Segmented Jaw Chucks. This is in part because the collet design has a much broader operative range. In addition, the disclosed collet chuck offers a quick-change feature for quick and effortless swapping out of different size jaw sets for different size caps. The collet itself is a low cost one-piece component with a number of downwardly protruding tines for gripping a cap. The collet may have urethane-lined jaws to drive caps with lower torque requirements, or machined contact is profile jaws to drive caps with high torque requirements (positive interlocking with the external cap profile). Given either arrangement, even asymmetric caps can be clamped into the collet without requiring a special chuck change (collet orientation relative to the chuck is always an exact repeat and servo drive allows an exact chuck orientation repeat). There is virtually no down time (or skill level) associated with the collet change. 
     The above-described collet chuck was designed for caps that require screw-insertion onto containers. However, many other caps are crimped onto containers. FIGS. 1-3 generally illustrate the crimping process. 
     FIG. 1 is a front view of a pharmaceutical vial  30  with a conventional read seal over-cap including plastic cap  10  and aluminum hood  20 . The crimping process begins vial  30  or other container formed with a neck, and a cap having a deformable aluminum hood  20  to be crimped around the neck of the vial  30 . As is known in the art, plastic cap  10  is bonded to the hood  20  but can be removed to expose a sealed but penetrable opening through the hood and into the medicine in vial  30 . 
     FIG. 2 is a front view of the pharmaceutical vial  30  of FIG. 1 with read seal over-cap in place but unsealed. The capping process entails placing the cap  10  and hood  20  onto the vial  30  as shown. Once fully installed, the aluminum hood  20  is crimped around the neck of the vial  30  to provide a fluid-tight seal. 
     FIG. 3 is a front view of the pharmaceutical vial  30  of FIGS. 1-2 with read seal over-cap in place and sealed by crimping of the aluminum hood  20 . 
     It would be greatly advantageous to adapt the screw-cap collet chuck design as shown and described in the above-described U.S. patent application Ser. No. 09/222,475 entitled “QUICK-CHANGE COLLET CHUCK”, filed Dec. 29, 1998, for use as a collet crimping head to allow crimping of hoods of over caps around the necks of containers such as vials in order to provide a fluid-tight seal. 
     SUMMARY OF THE INVENTION 
     It is, therefore, an object of the present invention to provide an improved collet crimping head for use in handling virtually any over-cap bottle seating. 
     It is still another object to provide a collet crimping head which incorporates a unitary crimping collet for increased durability and reliability, lower manufacturing cost, and greater ease of handling. 
     It is a further object to provide a crimping head as described above with the lowest inertia possible so as not to interfere with high speed operation. 
     It is another object to provide an optional quick-change ability for the above-described collet crimping head to enable quick and effortless no-tool swapping out of different size crimping heads for different size caps while minimizing any interruption of the container capping process. 
     Additional objects include stainless construction. 
     In accordance with the above objects, an improved collet crimping head is described for use in an existing single lane capping apparatus for gripping, crimping and sealing aluminum hoods of over-caps onto the necks of existing containers. The collet crimping head is a unitary member formed with an upper mounting collar for attachment to the chuck of the automatic capping assembly. The collet crimping head also has a lower cap crimping section including an inwardly directed and constrictable crimping collar for crimping and sealing aluminum hoods of said over-caps onto the necks of containers. The collet crimping head has a slim profile for low inertia and will not interfere with high speed operation. 
     An optional quick-change feature is also disclosed to allow quick and effortless swapping out of different size crimping collets for different size caps while minimizing interruption and down time of the automated container capping processes. 
     The collet crimping head of the present invention was specifically developed for cap positioning and crimping of pharmaceutical containers, although it should be understood that the inventive concept may apply in many other crimping contexts. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiment and certain modifications thereof when taken together with the accompanying drawings in which: 
     FIG. 1 is a front view of a pharmaceutical vial  30  with a conventional read seal over-cap including plastic cap  10  and aluminum hood  20 . 
     FIG. 2 is a front view of the pharmaceutical vial  30  of FIG. 1 with read seal over-cap in place but unsealed. 
     FIG. 3 is a front view of the pharmaceutical vial  30  of FIGS. 1-2 with read seal over-cap in place and sealed by crimping of the aluminum hood  20 . 
     FIG. 4 is a side sectional view of a crimping collet  120  according to one embodiment of the present invention. 
     FIG. 5 is a side sectional view of the modified chuck assembly similar to that set forth in parent application Ser. No. 09/222,475 entitled “QUICK-CHANGE COLLET CHUCK”, filed Dec. 29, 1998, with crimping collet head  120  inserted therein. 
     FIG. 6 is a side sectional view of the modified chuck assembly as in FIG. 5 with the crimping collar  126  of crimping collet head  120  shown constricted. 
     FIGS. 7 and 8 are an end view and a side cross-section, respectively of the shaft  103  of FIGS. 5 and 6. 
     FIGS. 9,  10 ,  11  and  12  are an end view, a side cross-section, a side cross-section rotated by 90 degrees, and an opposing end view, respectively, of the crimping head housing  142  of FIGS.  5  and  6 .. 
     FIGS. 13,  14  and  15  are an end view, a side cross-section, and side cross-section rotated by 90 degrees, respectively, of the cylindrical sleeve  101  of FIGS.  5  and  6 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The crimping head of the present invention is designed for use in an existing single lane capping apparatus chuck substantially as shown and described in parent application Ser. No. 09/222,475 entitled “QUICK-CHANGE COLLET CHUCK”, filed Dec. 29, 1998. However, rather than screw-caps, the crimping head is designed for inserting and crimping conventional over-caps onto containers as shown in FIGS. 1-3. 
     FIG. 4 is a side sectional view of a crimping collet  120  according to one embodiment of the present invention. The crimping collet  120  is a generally cylindrical unitary member formed with an upper mounting collar  122 , a downwardly extending mid section  124 , and a lower cap gripping/crimping section  126 . The downwardly extending mid section  124  has an angled step  125  toward the bottom. 
     The upper mounting collar  122  of crimping collet  120  is machined with a transverse through-bore  129  to receive a pin  105  as will be described. 
     The crimping head  120  is formed with a generally hollow interior, and the interior surface of the lower cap gripping/crimping section  126  is formed with a constricted crimping collar  127 . 
     The downwardly extending mid section  124  and lower cap gripping/crimping section  126  are interrupted by a plurality of longitudinal axial notches  121  which define tines that give the cap gripping/crimping section  126  the ability to expand or contract to release/grip and crimp an over-cap inserted therein. Presently, four notches  121  spaced uniformly and radially about the crimping head  120  are preferred (thereby giving four tines), each terminating below the mounting collar  122  and extending through the cap gripping/crimping section  126 . 
     The crimping collet  120  of FIG. 4 fits into a chuck substantially as shown in parent in application Ser. No. 09/222,475, with slight modifications to effect a proper crimping operation. 
     FIG. 5 is a side sectional view of the modified collet chuck  20  with crimping collet  120  inserted therein. 
     The collet chuck  20  is secured to the existing mounting block  140  of the capping apparatus, and a drive shaft  113  as supplied with the existing capping apparatus  10  is shown protruding into the collet chuck  20 . 
     The collet chuck  20  consists of a crimping head housing  142  that is secured to the existing mounting block  140  of the capping apparatus, and a shaft  103  that passes through crimping head housing  142  and that connects with the hollow drive shaft  113  supplied with the existing capping apparatus  10 . 
     The crimping head housing  142  is machined toward its lower extremity with a through-bore  110  to receive a pin  105  as shown. Shaft  103  is machined toward its upper extremity with an oblong through-bore  111  to receive pin  105 . Pin  105  fits tightly into the through-bore  110  in crimping head housing  142  and loosely through a cylindrical sleeve  101  (to be described) as well as the oblong through-bore  111  in shaft  103  in a slidable manner. In this manner, crimping collet  120  may be inserted over the end of shaft  103  and captured by pin  105 , thereby retaining the crimping collet  120  with a slidable degree of freedom. 
     FIGS. 7 and 8 are an end view and a side cross-section, respectively of the shaft  103 . Shaft  103  is a substantially cylindrical member that is formed with a tip  109  having a threaded bore  107  for coupling to the hollow drive shaft  113  supplied with the existing capping apparatus  10 . Shaft  103  is shown with an oblong through-bore  111  for slidably receiving pin  105 . 
     Referring back to FIG. 5, and as shown and described in parent application Ser. No. 09/222,475, an air supply is directed through side ports into an internal cavity of the mounting block  140 . The crimping head housing  142  is secured by machine screws or the like to the underside of the existing mounting block  140  of the capping apparatus. The crimping head housing  142  is open at both ends and defines an internal sliding surface for cylindrical sleeve  101  (to be described). 
     FIGS. 9,  10 ,  11  and  12  are an end view, a side cross-section, a side cross-section rotated by 90 degrees, and an opposing end view, respectively, of the crimping head housing  142 . The crimping head housing  142  is a generally annular hollow member formed with a plurality of set screw holes  143  spaced radially around one end as required for connection to the existing capping apparatus. The crimping head housing  142  is machined toward its lower extremity with a through-bore  110  to receive the pin  105  (of FIG.  5 ). Through-bore  110  is dimensioned to retain pin  105  tightly therein. 
     FIGS. 13,  14  and  15  are an end view, a side cross-section, and side cross-section rotated by 90 degrees, respectively, of the cylindrical sleeve  101 . Cylindrical sleeve  101  is a unitary generally tubular cylindrical member having a recessed partition  119  substantially closing one end. Partition  119  is defined by a central aperture  109  for passing the shaft  103  that connects with the hollow drive shaft  113  supplied with the existing capping apparatus  10 . 
     The recess defined by partition  119  of cylindrical sleeve  101  serves to retain a compression spring  104  that is required for return of the cylindrical sleeve  101  (after the air pressure is removed). Compression spring  104  is a conventional steel spring that, when seated, bears against the upper portion  140 A of the crimping head housing. 
     As seen in FIG. 15, the cylindrical sleeve is also machined with an oblong through-bore  106  below the partition  119 , and pin  105  (of FIG. 5) fits through this oblong through-bore  106  in a slidable manner. 
     The crimping collet  120  of FIG. 4 fits into the cylindrical sleeve  101  in close conformity with both the mounting collar  122  and flat portion directly above the angled step  125  (toward the bottom). This supports the crimping collet  120  yet leaves it free to slide within the cylindrical sleeve  101 . Shaft  103  protrudes downward through the crimping collet  120  until its oblong through-bore  111  is aligned with the through-bores  106 ,  129 , and  110  in cylindrical sleeve  101 , crimping collet  120 , and crimping head housing  142 , respectively. Again, pin  105  fits loosely through oblong through-bores  106  and  111  in shaft  103  and cylindrical sleeve  101 , respectively in a slidable manner. The lengthwise extent of the oblong through-bores  106  and  111  in shaft  103  and cylindrical sleeve  101 , respectively, can be chosen to limit the downward actuation of cylindrical sleeve  101 . On the other hand, pin  105  fits tightly through the through-bores  129  and  110  in crimping collet  120 , and crimping head housing  142 , respectively. This effectively fixes the position of the crimping collet  120  with respect to crimping head housing  142 . 
     In operation, the crimping collet  120  is positioned over a container  30  (as in FIG. 1) with over-cap (comprising plastic cap  20  and aluminum hood  30 ) as yet unsealed but lightly seated within the interior surface of the lower cap gripping/crimping section  126 . Air is supplied through side ports into the internal cavity of the sealed crimping head housing  140 . The cavity  711  is pressurized and shaft  103  is urged downward. The bias of spring  104  forces cylindrical sleeve  101  to follow. 
     FIG. 6 is a side sectional view of the crimping collet  120  of FIG. 5 inserted into the quick-change chuck assembly described above. The action of the crimping collet  120  is as follows. As the shaft  103  is forced down, the spring  104  forces the cylindrical sleeve  101  to follow. Cylindrical sleeve  101  is biased downward until it encounters the angled step (or ramped bearing surface)  125  toward the bottom of the crimping collet  120 . The annular lower lip of the Cylindrical sleeve  101  bears against the ramped bearing surface  125  of the crimping collet  120 . As the Cylindrical sleeve  101  is forced down, the inner face of the Cylindrical sleeve  101  forces the lower cap gripping/crimping section  126  of the crimping collet  120  to flex inward (contract) and finally lock closed. The constricted (locked) crimping collar  127  around the interior surface of the lower cap gripping/crimping section  126  forms a continuous radial die surface. As the shaft  103  continues its travel, it seals the aluminum hood  20  by swaging it between the closed continuous die surface formed by the constricted (locked) crimping collar  127  of the crimping collet  120  and its own the contact surface, thereby sealing the aluminum hood  20  of the over-cap onto the neck of the container  30 . Once the air pressure is released, the shaft  103  is retracted. Once the shoulder of the shaft  103  (formed by the tip  109 ) hits the cylindrical sleeve  101 , cylindrical sleeve  101  is retracted thereby compressing spring  104 . The crimping collet  120  is allowed to flex open again as the sleeve retracts off the flared mid section of crimping collet  120 . 
     It is noteworthy that pin  105  may be a readily removable detent pin to allow quick-change tool-less swapping out of different collet crimping heads  120  for different size caps while minimizing interruption and down time of the automated container capping processes. Alternatively, an equivalent quick-change feature may be accomplished by forming the mounting collar  122  of crimping collet  120  with a hooked channel as shown and described in parent application Ser. No. 09/222,475 entitled “QUICK-CHANGE COLLET CHUCK”, filed Dec. 29, 1998, the contents of said disclosure being incorporated herein by reference. 
     Having now fully set forth the preferred embodiments and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with said underlying concept. It is to be understood, therefore, that the invention may be practiced otherwise than as specifically set forth herein.