Abstract:
A manually actuatable, part feeder presents at least one exposed part, with an appropriate orientation for picking and placing, to an operator in a pick station, in response to the operator providing a feed command. A cover take-up mechanism can be used to remove a cover tape from the carrier such that the operator receives the exposed part or parts to be picked. Tape advance is achieved by applying forces to the carrier tape to advance the pocketed component carrying portion. Variable widths of carriers can be accommodated in the feeder. A pair of movable hold-down rails, laterally adjustable with respect to one another, makes it possible to feed carriers having a wide range of widths simply by adjusting the spacing of the rails relative to one another.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention pertains to equipment for feeding parts for assembly of product. More particular, the invention pertains to such part feeders which are suited for use in semi-automatic or manual, final assembly or manufacturing processes.  
         BACKGROUND OF THE INVENTION  
         [0002]    Numerous types of products are assembled, in whole or in part, on substantially automated assembly lines without direct human intervention. Examples of these include electronic products and subassemblies thereof.  
           [0003]    Carrier tape is a form of packaging used for different kinds of smaller components or parts. It is made of polystyrene and other polymers with different thicknesses between 0.15 mm and 0.50 mm and varies in width between 8 mm and 200 mm called flastock.  
           [0004]    The flat stock is heated and formed in a thermoforming machine. The result is a pocketed tape with shaped pockets, specific for every component that is supposed to be packed. When the component or part is packed, the pocket is sealed with a cover film called cover tape thereby forming a two-part carrier tape. The advantage in using carrier tape compared to other packaging solutions is that the product reaches the customer in the same way it was packed, it will stay scratch and dust free. The product volume is also very high compared to competing solutions.  
           [0005]    Known assembly machines often incorporate components carried in standardized carrier tape. The respective carrier tape usually includes the cover tape to retain the part properly within the carrier during shipment and assembly.  
           [0006]    Known carrier tapes are intended to be loaded into automatic part feeding machinery. Known machines will, for example, unwind a loaded carrier tape, strip off the cover tape and automatically provide for the removal of parts one at a time from the respective carrier tape and to the appropriate location in the pick and place assembly machinery.  
           [0007]    The tapes, if perforated with sprocket or index holes can be advanced with a sprocket mechanism. Alternately, a linearly moving tape advance mechanism can be used.  
           [0008]    Equipment for feeding carrier tape already exists on the market. Known equipment feeds the carrier tape with two cogwheels that run in the sprocket holes in the carrier tape. The carrier tape is wound up on a separate roll that uses the same drive force as the forward feeding but uses a slip friction clutch because of the increasing diameter of tape wound on the roll when the carrier tape winds up.  
           [0009]    Known equipment is made to present a component in a specific position with very close tolerances in automated production lines. The need for close tolerance leads to high investment costs. Such machinery, while well suited for high volume mass production wherein the necessary capital investment can be spread across a large number of products, is, for a variety of reasons, often unsuited for lower volume, lower speed semiautomated assembly lines which involve human operators.  
           [0010]    The market today is evolving toward manual assembly production in low labor cost countries. But still the carrier tape, as packaging, is the preferred way to pack and ship the components.  
           [0011]    There is no known available equipment to present the carrier tape packed components for a manual work situation. All existing equipment is relatively expensive; and, designed only for fully integrated automatic assembly line situations.  
           [0012]    Lower speed manual or semi-automatic assembly lines often use carrier trays for the parts. While less efficient than carrier tapes, the trays are well suited to lower speed manual or semi-automatic assembly lines.  
           [0013]    There continues to be a need for less expensive, carrier tape based part feeders which are usable in conjunction with human operators in semiautomatic, lower speed and lower volume production lines. Preferably, such part feeders could be implemented with relatively low technology apparatus suitable for installation and use by operators of relatively limited skill levels in relatively low technology-type manufacturing lines.  
         SUMMARY OF THE INVENTION  
         [0014]    A semi-automatic part feeder in accordance with the invention can be used in manual, one-at-a-time processes for assembly or sub-assembly of electronic products. Typical products include cellular telephones, circuit boards, pagers and other products or sub-assemblies thereof, where manual assembly is to be used.  
           [0015]    In accordance herewith, the present part feeder can present a part in a preformed pocket in an elongated carrier tape to a pick station. The part is presented to an operator in the correct orientation for extraction and insertion.  
           [0016]    The operator can manually pick the part from the carrier tape, for example with a hand-held vacuum wand. The part can then manually be placed into a sub-assembly or assembly such as a cellular phone or a pager.  
           [0017]    In accordance herewith, the part is presented not only with the correct orientation for extraction and insertion, but also in a way which facilitates same. For example, sufficient clearance is provided relative to the part to permit easy and convenient use of the and to pick and to insert the part into assembly.  
           [0018]    A manually operated switch, for example a foot operated switch, can be used to index one part at a time, or a group of parts, to the pick station. Alternately, a hand crank can be used to advance the tape.  
           [0019]    Parts are supplied on pre-loaded reels of carrier tape. The parts are retained in their molded pockets in the tape by an overlying cover tape.  
           [0020]    In another aspect of the invention, the loaded carrier tape can be unwound from a rotatably mounted reel. A cover tape take-up mechanism can be used to peel back the cover tape such that the operator is presented with an uncovered part at the pick station. This part can readily be extracted from the carrier pocket using the vacuum wand. The socketed tape is oriented so that gravity holds the parts in their respective pockets even in the absence of the cover tape.  
           [0021]    The cover tape take-up mechanism not only peels off the cover tape, it applies a feed force to the carrier tape. The applied feed force advances the next loaded pocket of the tape to the pick station. Thus, the component carrying pocketed portion of the tape is not advanced using some form of indexing mechanism. It is drawn forward by the take-up forces applied to the cover tape.  
           [0022]    First and second rails or guides, at least one of which is laterally adjustable, can be used to hold-down the pocketed tape so that it remains adjacent to the pick station. Various widths of tape can be used with the feeder merely by adjusting the spacing between the hold-down rails. This configuration is unlike prior art automatic feeders which are dedicated width units.  
           [0023]    The present feeder assembly is a very flexible apparatus capable of feeding parts off of tapes having widths in a range from 5 to 250 mm. Unloaded sections of pocketed tape can be dumped into a container for recycling.  
           [0024]    Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]    [0025]FIG. 1 is a perspective view of a part feeder in accordance with the present invention;  
         [0026]    [0026]FIG. 2 is an enlarged perspective view of a portion of the feeder illustrated in FIG. 1;  
         [0027]    [0027]FIG. 3 is an enlarged perspective view of a portion of the feeder illustrated in FIG. 2;  
         [0028]    [0028]FIG. 4 is a front elevational view of the feeder illustrated in FIG. 1;  
         [0029]    [0029]FIG. 5 is an enlarged fragmentary front elevational view of a portion of FIG. 4;  
         [0030]    [0030]FIG. 6 is another perspective view of the feeder of FIG. 1 illustrating various details in phantom;  
         [0031]    [0031]FIG. 7 is a side elevational view of another part feeder in accordance with the invention; and  
         [0032]    [0032]FIGS. 8A, B, C illustrate different views of a collapsible cover tape spindle usable with the feeder of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0033]    While this invention is susceptible of embodiment in many different forms, there are shown in the drawing and will be described herein in detail specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated.  
         [0034]    [0034]FIG. 1 illustrates a part feeder  10  in accordance with the presence of the present invention. Feeder  10  is supported on a support surface S. One or more feeders  10  can be positioned next to one another on surface S. Hence, a plurality of different parts can be presented to an operator simultaneously.  
         [0035]    Feeder  10  includes a support frame or housing indicated generally at  12  which carries various portions of the feeder  10 . A carrier tape support bracket and feed mechanism  14  is coupled to and carried on the frame  12 . The support  14  rotatably supports a reel R of a loaded carrier tape T.  
         [0036]    The reel R and tape T could carry a wide variety of parts and could have a structure in accordance with any of the recognized standards for part carriers or carrier tapes. It will be understood that the specific nature of the parts carried on the tape T is not a limitation of the present invention.  
         [0037]    Tape T is preferably a two-part tape having a cover tape C and a pocketed section P. The cover tape C is adhesively attached to section P.  
         [0038]    Section P includes a plurality of spaced apart pockets P 1 , P 2  . . . Pn. One or more components can be carried in each pocket Pi as would be understood by those of skill in the art.  
         [0039]    Tape T is fed off of reel R by a feed mechanism indicated generally at  18 . Feed mechanism  18  which is carried on frame  12  could for example include an electric motor  18 - 1  coupled by a gear train  18 - 21  (best seen in FIG. 6) to a take-up reel  18 - 3  for cover tape C.  
         [0040]    As the motor  18 - 1  is energized by drive circuits  18 - 6  on printed circuit board  18 - 7  (also best seen in FIG. 6), the tape-up reel  18 - 3  is driven to rotate in a direction R 1 . As the take-up reel  18 - 3  rotates, it pulls cover tape C wrapped thereon off of, and away from, pocketed section P over roller  18 - 8 , in a direction D 1 .  
         [0041]    The force applied by take-up reel  18 - 3  also advances the tape T and pocketed section P in a direction D 2 . The advancing pockets Pi are oriented so as to use the force of gravity to retain the component(s) in the respective pocket(s). As the tape T advances in direction D 2 , it unwinds from reel R. The cover tape C is wound onto take-up reel  18 - 3  with a peel angle in a range of 25 to 40 degrees depending on the diameter of the roll of cover tape C on the take-up reel  18 - 3 .  
         [0042]    As the tape T is fed off of reel R by feed mechanism  18 , the peripheral edges thereof E 1 , E 2  slide under and are retained by rails  22   a  and  22   b . The rails  22   a ,  22   b  are laterally movable relative to one another to enable feeder  10  to feed tapes of differing widths. Only one of the rails  22   a , needs to be adjustable relative to the other. Preferably, the rails are adjustable relative to one another to retain tapes having a width in a range of 5 mm to 250 mm.  
         [0043]    The rails  22   a, b  provide slots  24   a, b  on the order of 1 mm through which the edges E 1 , E 2  slide. The tape T enters the slots  24   a, b  before the cover tape C is stripped from the section P.  
         [0044]    Once the pocketed section P passes the cover tape take-up reel  18 - 3 , it enters a pick area  32 . The pick area  32  is defined by an enlarged open region  32  in cover  46  of housing  12 . The respective carrier tape pocket, such as pocket Pi, is presented to an operator with an appropriate orientation and with enough clearance in the pick area  32  to facilitate easy extraction of the respective component or part from the pocket Pi.  
         [0045]    The size of the pick region  32  can be altered by replacing cover  46  with a cover having a pick region of a desired size. Hence, various sizes of pockets can easily be compensated for. In addition, multiple pockets can be presented with a single tape motion in a single pick region if desired.  
         [0046]    An operator, not shown, can use a vacuum wand  38  to pick the respective part, from the pocket Pi for transfer to an assembly or subassembly being manufactured. As each part is removed from the respective pocket, via wand  38 , the operator indexes the advance mechanism  18  moving the next pocket Pi, and associated part, into the pick area  32 .  
         [0047]    The mechanism  18  can be triggered to advance the tape T one index position at a time using a foot switch  38   a  or a hand switch  38   b . In an alternate embodiment, a crank or shaft can be coupled to the advance mechanism  18  to mechanically advance the tape T using non-electrical energy.  
         [0048]    The amount of advance or pitch for each cycle can be set, based on the size of the pockets Pi, using switches  40  generally indicated in FIG. 6. A display  42  can be provided to indicate current pitch setting.  
         [0049]    Feedback is provided by a sprocket wheel carried on printed circuit board  44 . The sprocket wheel engages sprocket holes in section P and is advanced thereby. Once motor  18 - 1  has been energized, it will run until the section P has been advanced an appropriate number of sprocket or index holes.  
         [0050]    It will be understood that the pick region  32  can be configured to expose two or more pockets Pi with each index cycle. An operator can thus pick and place multiple components or parts during each cycle. Conversion from one pick area to another is easily accomplished by replacing cover  46  which defines pick region  32 .  
         [0051]    Once the tape T has passed through pick region  32 , it continues to be fed via the rails  22   a ,  22   b  and moves to a distal region of the feeder  10 . The unloaded tape T can then be accumulated in a scrap or recyclable container for subsequent processing.  
         [0052]    It will be understood that the feeder  10  is particularly advantageous in that as the tape T is feed into the pick region  32 , with the cover tape removed, the orientation of the part is such that gravity continues to hold the part into the respective pocket Pi. At the same time, the part is readily available to the pick-up end of the wand  38  for the convenience of the operator. As noted above, the pick region  32  is designed to facilitate extraction by providing clearance for the operator to use the vacuum wand  38  to remove the parts. Alternatively, pick region  32  can be designed to permit manual extraction of parts by an operator.  
         [0053]    Another advantage of the part feeder  10  is that it is a relatively low cost easy-to-use mechanism which is well-suited to semi-automatic assembly type manufacturing using personnel of limited skills where only modest capital investments in assembly equipment can be justified. Additionally, the relatively non-complex nature of the feeder  10  is very beneficial in that it can be maintained and kept operational by personnel of limited skills and with limited tools and parts.  
         [0054]    [0054]FIG. 7 illustrates an alternate embodiment  10 ′ of a part feeder in accordance with the present invention. The same identification numerals have been used in FIG. 7, designated with a prime, as were used in FIGS.  1 - 6  for corresponding structures. As illustrated in FIG. 7, part feeder  10 ′ extracts tape T′ from reel R′ using an electric motor, such as electric motor  18 - 1 ′ to strip cover tape C′ from pocketed portion P′. The pocketed portion P′ is fed beneath cover  46 ′ to a pick region indicated generally at  32 ′ for the convenience of an operator.  
         [0055]    In the part feeder  10 ′, housing  12 ′ incorporates a variable depth floor  12 ′- 1  whose depth can be set using mechanism  12 ′- 2  to compensate for various depths of pockets P′i in the pocketed portion P′. As illustrated in FIG. 7, tape T′ slides across proximal rounded bottom plate  12 ′- 3  as it is being advanced by the motor  18 - 1 ′, stripping the cover tapes C′. Guide rails, comparable to guide rails  22   a, b ; are provided in feeder  10 ′ beneath cover  46 ′. As discussed above, the tape T′ is advanced by electric motor  18 - 1 ′ stripping cover tape C′ and pulling it in a direction D 1 ′ which in turn advances the pocketed portion P′ in a direction D 2 ′ toward the pick region  32 ′. A printed circuit board comparable to printed circuit board  44  carried within housing  12 ′ provides similar functions described previously with respect to circuit board  44 .  
         [0056]    FIGS.  8 A-C illustrate a cover tape take-up assembly  50 . Assembly  50  is rotatable by motor or gear drive  52  as discussed previously to rotatably take up cover tape, such as cover tape C as in FIG. 1, so as to advance pocketed section P. Assembly  50  includes a rotatable, pivotably arranged spindle portion  54   a  and a separable expander  54   b.    
         [0057]    The cover tape C is wound onto rotatable elongated body elements  56   a, b  (configured as in FIG. 8A) between disks  58   a, b , best seen in FIG. 8C. Body elements  56   a, b  are pivotably attached, indicated generally at  60   a, b  to a coupling shaft rotatable by motor or gear drive  52 . The body elements are biased toward one another by an elastic member, such as O-ring  60 . In the configuration of FIG. 8B, elements  56   a, b  exhibit a tapered external periphery.  
         [0058]    When expander  54   b  is slidably engaged with spindle portion  54   a , the biasing forces are overcome and body elements  56   a, b  are forced to rotate away from one another thereby forming a generally cylindrical take-up reel of a substantially constant radius, best seen in FIG. 8A. When expander  54   b  is withdrawn from assembly  54   a , the free ends  56   a′, b′ move laterally toward one another, see FIG. 8B, and resume a tapered state.  
         [0059]    When a reel of removed cover tape C has been accumulated on assembly  50 , expander  58   b  can be removed therefrom. The reel of cover tape C can be slid from the tapered exterior periphery of elements  56   a, b . The reel of cover tape C can be cut loose and removed.  
         [0060]    Expansion element 58   b  can be reinserted axially between elements  56   a, b . The free end of cover tape C extending around cylinder  18 - 8  can be reattached to spindle  54   a . Part feeding and assembly can continue.  
         [0061]    It will be understood that while two pivotably attached elements  56   a, b  have been illustrated, three or four could be used. The number of such elements is not a limitation of the invention. As illustrated in FIG. 8C, the cover tape C, pealed off of pocketed portion P can be rolled onto the take-up reel in either direction R 1 , see FIG. 2, or direction R 2 . The exact details of take-up direction are not a limitation of the invention.  
         [0062]    From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.