Patent Publication Number: US-6698641-B2

Title: System for dispensing plastic fasteners

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a division USSN: 09/867,264 entitled SYSTEM FOR DISPENSING PLASTIC FASTENERS, filed on May 29, 2001, now U.S. Pat. No. 6,561,405, in the names of Steven E. Flannery, Paul A Davignon and Hidekatsu Kinbara. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to plastic fasteners and more particularly to devices used in the dispensing of plastic fasteners. 
     In U.S. Pat. No. 4,039,078 to A. R. Bone, which is incorporated herein by reference, there are disclosed several different types of plastic fasteners, or attachments, which are fabricated as part of continuously connected ladder stock. In each instance, the fastener has an H-shape, and the ladder stock is formed from two elongated and continuous plastic side members coupled together by a plurality of plastic cross links, the cross links preferably being equidistantly spaced. The stock may be produced from flexible plastics material including nylon, polypropylene and other similar materials by molding or by stamping. 
     Either manually or with the aid of specifically designed devices, individual fasteners may be dispensed from the ladder stock to couple buttons to fabric, merchandising tags to articles of commerce, or, in general, any two desired articles. In those instances where the dispensing device has dual needles, the attachments severed from the stock can be used like staples to secure objects and items. 
     Specifically designed devices for dispensing individual plastic fasteners are well known in the art. Plastic fastener dispensing devices are commonly used to sever individual plastic fasteners from continuously connected ladder stock and to attach the severed individual plastic fastener to items. 
     In commonly assigned U.S. Pat. No. 5,615,816, which is incorporated herein by reference, there is disclosed an apparatus for dispensing attachments from continuously connected ladder stock of the type comprising a pair of plastic side members coupled together by a plurality of plastic cross links. The apparatus includes a mount, a support movably mounted on the mount, and a pair of carrier blocks mounted on the support. A needle block is mounted on each carrier block and a hollow, slotted needle is mounted on each needle block. A feed mechanism including a pair of feed wheels, is mounted on the support for advancing the ladder stock into the hollow slotted needles and a pair feed tracks, one for each hollow slotted needle, are provided through which the ladder stock passes from the feed wheels into the pair of hollow slotted needles. A pair of knives are provided for severing an attachment from the ladder stock, and a pair of ejector rods are provided for ejecting the severed attachment through the hollow slotted needles. The carrier blocks are disposed parallel to each other and movable sideways relative to each other so that the spacing between the hollow slotted needles can be changed for different applications. The feed wheels are disposed parallel to each other and are capable of being moved sideways relative to each other so that their spacing can be changed to accommodate different widths of ladder stock. In order to provide a path for the ladder stock form the feed wheels to the hollow slotted needles for different feed wheel spacings and/or needle spacings, each feed track assembly includes a pivotally mounted section. 
     The apparatus disclosed in U.S. Pat. No. 5,615,816 is well known in the art and is commonly referred to in the art simply as a variable needle system (VNS). 
     Variable needle systems of the type described in U.S. Pat. No. 5,616,816 are commonly used in the art to secure a product for sale, such as a toy, hardware item or houseware item, onto a display card using one or more plastic fasteners. As can be appreciated, when used to secure a product for sale onto a display card, plastic fasteners are commonly referred to as elastic staples in the art. 
     It should be noted that the use of a variable needle system of the type described in U.S. Pat. No. 5,616,816 to secure a product of sale onto a display card using one or more elastic staples provides numerous advantages. Specifically, the capability of such a variable needle system to continuously dispense elastic staples from a roll of fastener stock increases the productivity in which an operator is able to secure products for sale onto associated display cards, which is highly desirable. Accordingly, variable needle systems of the type described in U.S. Pat. No. 5,616,816 are commonly used on assembly lines for packaging products. 
     It should also be noted that the use of elastic staples to secure a product of sale onto a display card provides numerous advantages. 
     As an example, the particular construction of an elastic staple creates aesthetic benefits which are highly desirable. Specifically, the use of elastic staples enables the product for sale to be mounted onto a display card, thereby enabling the product to be presented to the potential customer in an ideal packaging to see, feel and manipulate the product at the point of purchase. Furthermore, it has been found that the elastic staple is barely visible when securing a product for sale onto its associated display card. 
     As another example, the elasticity of the staple allows for the fastener to be used in a wide range of applications and in conjunction with a variety of differently sized products, which is highly desirable. 
     As another example, the elasticity of the staple allows for the fastener to conform tightly against the product for sale, thereby creating a strong and durable attachment of the product for sale onto its associated display card, which is highly desirable. As a result, the product remains securely fastened onto the display card until after purchase. 
     Although well known and widely used in the art for securing products for sale onto display cards, variable needle systems of the type disclosed in U.S. Pat. No. 5,615,816 suffer from a few notable drawbacks. 
     As a first drawback, the variable needle system disclosed in U.S. Pat. No. 5,615,816 is typically fixedly mounted onto a support structure. Accordingly, in use, the operator is required to manually urge the items to be coupled up against the pair of needles in such a manner so that the pair of needles penetrates through the items. As a consequence, it has been found that the user is at risk of inadvertently contacting the sharpened end of the needles, which is highly undesirable. 
     As a second drawback, the variable needle system disclosed in U.S. Pat. No. 5,615,816 is constructed so that the operator can insert the needles into and through the items to be coupled at variable depths. Specifically, the operator is unable to regulate the degree of insertion of the needles through the items. As a result, if the needles are inserted too far through the items, the fastener can become overstretched and, as a result, will break, which is highly undesirable. Furthermore, if the needles are not inserted far enough through the items, the fastener is unable to penetrate through the items, thereby precluding proper coupling, which is highly undesirable. 
     As a third drawback, the variable needle system disclosed in U.S. Pat. No. 5,615,816 fails to adequately support, or stiffen, the pair of needles. As a result, the needles are susceptible to bending and breaking when inserted through the items to be coupled together, which is highly undesirable. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a new and improved system for dispensing a plastic fastener from a reel of fastener stock to couple together two or more items. 
     It is another object of the present invention to provide a system as described above which includes at a pair of hollowed needles, each needle having a sharpened tip, wherein the pair of hollowed needles enable the plastic fastener to pass through the items to be coupled together. 
     It is yet another object of the present invention to provide a system as described above which protects the operator from inadvertently contacting the sharpened tip of the pair of needles. 
     It is still another object of the present invention to provide a system as described above which enables the operator to regulate the degree of insertion of the pair of needles through the items to be coupled together. 
     It is yet still another object of the present invention to provide a system as described above which adequately supports, or stiffens, the pair of needles. 
     It is yet a further object of the present invention to provide a system for dispensing a plastic fastener from a reel of fastener stock to couple together two or more items which has a limited number of parts, which is easy to use and which is inexpensive to manufacture. 
     Accordingly, as one feature of the present invention, there is provided a system for dispensing a plastic fastener from a reel of fastener stock to couple together two or more objects, said system comprising a module for dispensing the plastic fastener from the reel of fastener stock to couple together the two or more objects, and a counterbalance for supporting said module. 
     As another feature of the present invention, there is provided a module for dispensing a plastic fastener from a reel of fastener stock to couple together two or more objects, said module comprising a hollowed needle having a sharpened tip, a needle holder for holding said hollowed needle, a retractable needle guard assembly mounted onto said needle holder over said hollowed needle, a feed mechanism for advancing the fastener stock into said hollowed needle, a severing mechanism for severing the fastener to be dispensed through said hollowed needle from the fastener stock, and an ejection mechanism for ejecting the severed fastener through said hollowed needle. 
     Various other features and advantages will appear from the description to follow. In the description, reference is made to the accompanying drawings which form a part thereof, and in which is shown by way of illustration, a specific embodiment for practicing the invention. This embodiment will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. The following detailed description is therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings wherein like reference numerals represent like parts: 
     FIG. 1 is a perspective view of a variable needle system constructed according to the teachings of the present invention, the system being shown with the anvil mounted on a workstation, the workstation being shown in dashed form, the system also being shown with a supply of continuously connected ladder stock fed thereinto; 
     FIG. 2 is a fragmentary perspective view of the system shown in FIG. 1, the system being shown securing a product for sale onto a display card using a plastic fastener; 
     FIG. 3 is a front plan view of the product for sale secured onto the display card using a plastic fastener as shown in FIG. 2; 
     FIG. 4 is a perspective view of a length of continuously connected ladder stock which may be used with the system shown in FIG. 1; 
     FIG. 5 is a perspective view of the VNS module shown in FIG. 1, the VNS module being shown with a supply of continuously connected ladder stock fed thereinto; 
     FIG. 6 is an enlarged, fragmentary, perspective view of the VNS module shown in FIG. 1; 
     FIG. 7 is an exploded, perspective view of the VNS module shown in FIG. 1, the VNS module being shown with its enclosure removed; 
     FIG. 8 is an enlarged, fragmentary, perspective view of the VNS module shown in FIG. 1; 
     FIG. 9 is an enlarged, fragmentary, perspective view of selected components of the VNS module shown in FIG. 1; 
     FIG. 10 is an enlarged, exploded, fragmentary, perspective view of selected components of the VNS module shown in FIG. 1; 
     FIG. 11 is an enlarged, exploded, fragmentary, perspective view of selected components of the VNS module shown in FIG. 1; 
     FIG. 12 is a enlarged, fragementary, front plan view of the VNS module shown in FIG. 1, the VNS module being shown with its enclosure removed; 
     FIG. 13 is a side view of the fixedly mounted needle guard of the first retractable needle guard assembly shown in FIG. 1; 
     FIG. 14 is a side view of the movable needle guard of the first retractable needle guard assembly shown in FIG. 1; 
     FIG. 15 is a side view of the first retractable needle guard assembly shown in FIG. 1, the first retractable needle guard assembly being shown in its protective position and disposed over a needle, the needle being shown in dashed form; 
     FIG. 16 is a side view of the first retractable needle guard assembly shown in FIG. 1, the first retractable needle guard assembly being shown in its retracted position and disposed over a needle, the needle being shown in dashed form; 
     FIG. 17 is a fragmentary, exploded, perspective view of the mounting stand shown in FIG. 1, the mounting stand being shown mounted on a workstation, the workstation being shown in dashed form; 
     FIG. 18 is a fragmentary, exploded, perspective view of the mounting stand shown in FIG. 1, the mounting stand being shown mounted on a workstation, the workstation being shown in dashed form; 
     FIG. 19 is a fragmentary exploded, perspective view of the counterbalance and mounting stand shown in FIG. 1; and 
     FIG. 20 is a fragmentary, exploded, perspective view of the counterbalance, mounting stand, reel holder and continuous supply of fastener stock shown in FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to FIG. 1, there is shown a variable needle system (VNS) constructed according to the teachings of the present invention, the system being identified generally by reference numeral  10 . As will be described further in detail below, system  10  is designed for use in dispensing plastic fasteners from a supply of continuously connected ladder stock  11 . 
     As such, system  10  can be used in an automated packaging line. Specifically, system  10  may be used, for example, to secure a product P for sale, such as a toy, hardware item or houseware item, onto to a cardboard display card C using one or more plastic fasteners, as shown in FIGS. 2 and 3. 
     Continuous Supply of Ladder Stock  11   
     Supply of continuously connected ladder stock  11  represents any well known continuous supply of plastic fasteners. For example, ladder stock  11  may be of the type described in U.S. Pat. No. 5,615,816 to Charles L. Deschenes et al. Specifically, FIG. 4 shows a perspective view of a prior art length of continuously connected ladder stock  11  with which the system of this invention may be used. Ladder stock  11  is preferably made of plastic and comprises a pair of side members  13  and  15  interconnected by a plurality of cross links  17 . A fastener  18  which is obtained from ladder stock  11  is shown in FIG.  4  and is commonly referred to as an elastic staple in the art. Fastener  18  comprises a pair of end bars  19  and  21  which are interconnected by a filament  23 , end bars  19  and  21  comprising sections of side members  13  and  15 , respectively, and filament  23  comprising a cross link  17 . 
     It should be noted that, for simplicity purposes only, system  10  will be described for use with ladder stock  11 . However, it is to be understood that system  10  could be described for use with alternative types of ladder stock without departing from the spirit of the present invention. Specifically, system  10  is capable of being adjusted to accommodate changes in the size of the ladder stock to be used and also to adjust the needle spacing to accommodate changes in the size of the products with which the attachments are to be used. 
     It should be noted that ladder stock  11  is preferably wound onto a reel  27 , reel  27  being sized and shaped to hold a supply of ladder stock  11  which includes approximately 10,000 fasteners  18 . As such, the high volume reel  27  of fasteners  18  enables for continuous operation of system  10 . 
     System  10  for Dispensing Plastic Fasteners  18   
     System  10  comprises a VNS module  29  for dispensing plastic fasteners  18  so as to secure a product P onto a display card C, a mounting stand  31  affixed to a workstation W, a counterbalance  33  affixed to workstation W for supporting VNS module  29 , a reel holder  35  affixed to mounting stand  31  for supporting reel  27  of fastener stock  11  and an anvil  37  mounted onto workstation W for supporting product P and display card C. It should be noted that portions of system  11  not pertinent to this invention are neither shown nor described in detail herein. 
     VNS Module  29  for System  10   
     Referring now to FIGS. 5-7, VNS module  29  comprises a frame  39  and an enclosure  41  which are secured together by a plurality of screws  42 , frame  39  and enclosure  41  together defining an internal cavity  43 . 
     A handle  45  is fixedly mounted onto the exterior of enclosure  41  and serves to enable an operator to freely handle VNS module  29 . In addition, a feed guide slot  47  is formed in enclosure  41 , feed guide slot  47  being in communication with internal cavity  43 . 
     A U-shaped bracket  49  is fixedly mounted onto frame  39  and includes a first tab  51  and a second tab  53 . First tab  51  of U-shaped bracket  49  extends perpendicularly away from the top of frame  39  and is shaped to include an elongated feed slot  55 . Second tab  53  of U-shaped bracket  49  extends perpendicularly away from the top of frame  39  and shaped to include an elongated feed slot, or fastener guide slot,  57  and a clip opening, or tether ring,  59 . 
     As such, supply of fastener stock  11  is fed into VNS module  29  in the following manner. Specifically, the free end of fastener stock  11  is fed from reel  27 , through feed slot  55  formed in first tab  51 , through feed slot  57  formed in second tab  53 , down through feed guide slot  47  and into internal cavity  43 , as shown in FIG.  5 . 
     It should be noted that, by disposing tether ring  59  above fastener guide slot  57 , fastener stock  11  is capable of being fed from behind VNS module  29  and into feed guide slot  47  while VNS module  29  is suspended from counterbalance  33 , as shown in FIG. 1, which is highly desirable. 
     Needles  75  for VNS Module  29   
     Referring now to FIGS. 7-11, VNS module  29  further comprises first and second spaced apart support plates  61 - 1  and  61 - 2  which are affixed onto frame  39  with screws  63 , support plates projecting out orthogonally from frame  39 . 
     First and second needle blocks  65 - 1  and  65 - 2  are mounted on a shaft  67  which extends laterally between first and second support plates  61 - 1  and  61 - 2 . A manually rotatable needle spacing knob  69  is fixedly mounted onto one end of shaft  67 . As can be appreciated, rotation of knob  69  laterally displaces first needle block  65 - 1  towards and away from second needle block  65 - 2 , second needle block  65 - 2  remaining at a fixed position on shaft  67 . In this manner, knob  69  can be used to adjust the spacing between needle blocks  65 . 
     First and second needle holders  71 - 1  and  71 - 2  are fixedly mounted onto first and second needle blocks  65 - 1  and  65 - 2 , respectively, by screws  73 . 
     First and second hollowed needles  75 - 1  and  75 - 2  are mounted onto first and second needle holders  71 - 1  and  71 - 2 , respectively. Each needle  75  is conventional in construction and includes a first end  77 , a second end  79 , an elongated channel  81  and an elongated slot  83  in communication with elongated channel  81 . First end  77  of each needle  75  is sized and shaped to be fittingly disposed within a needle receptacle  78  formed in its associated needle holder  71 , thereby enabling each needle  75  to project perpendicularly out from its associated needle holder  71 . Second end  79  of each needle  75  is in the form of a spoon-shaped sharpened tip through which an end bar of fastener  18  may pass during the dispensing process. 
     As can be appreciated, the rotation of knob  69  enables needle  75 - 1  to slide laterally, as represented by arrow A in FIG. 11, towards and away from fixed needle  75 - 2  in order to adjust the spacing between needles  75 . 
     Ejection Mechanism  84  for VNS Module  29   
     Referring now to FIGS. 7,  9  and  12 , VNS module  29  also comprises an ejection mechanism  84  for dispensing a fastener  18  out through needles  75 . Ejection mechanism  84  includes an ejector rod slide  85  which is adapted to slide vertically along frame  39 , said ejector rod slide  85  comprising a pair of spaced apart sidewalls  87 , a top wall  89  affixed to sidewalls  87 , a plate  91  affixed to top wall  89 , a bottom wall  93  affixed to sidewalls  87  and a ramp  95  formed onto bottom wall  93 . Ejector rod slide  85  is powered for vertical displacement by an pneumatic system (not shown) which operates on 80 psi. Application of air pressure from the pneumatic system is achieved through the depression of an actuation button  97  formed on handle  45 . 
     Ejection mechanism  84  also includes first and second ejector rods  99 - 1  and  99 - 2  which are disposed within a slot  101  formed into top wall  89  and are retained therein through the mounting of plate  91  onto top wall  89 . Ejector rods  99 - 1  and  99 - 2  are positioned to extend down through needle blocks  65 - 1  and  65 - 2 , respectively. Accordingly, as ejector rod slide  85  travels downward, first and second ejector rods  99 - 1  and  99 - 2  project into channel  81  of first and second needles  75 - 1  and  75 - 2 , respectively, so as to dispense fastener  18  out from VNS module  29 . 
     As can be appreciated, ejector rod slide  85  is adapted to slide vertically along frame  39  and includes a downward stroke in which first and second ejector rods  99 - 1  and  99 - 2  project into channel  81  of first and second needles  75 - 1  and  75 - 2 , respectively, and an upward stroke in which first and second ejector rods  99 - 1  and  99 - 2  retract from needles  75 - 1  and  75 - 2 , respectively. 
     It should be noted that the construction and functionality of ejection mechanism  84  does not serve as a principal feature of the present invention. As a result, it is to be understood that ejection mechanism  84  could be of the type disclosed in U.S. Pat. No. 5,615,816 to Charles L. Deschenes et al. without departing from the spirit of the present invention. 
     Feed Mechanism  103  for VNS Module  29   
     VNS module  29  further comprises a feed mechanism  103  for continuously advancing fastener stock  11  therethrough. Feed mechanism  103  comprises a pair of spaced apart, sprocket feed wheels  105  which are fixedly mounted onto a shaft  107 , as shown in FIG.  7 . Feed wheels  105  are adapted to engage the filaments  23  of fasteners  18  to advance the supply of fastener stock  11  through VNS module  29 . A feed knob  109  is fixedly mounted onto shaft  107  to allow for manual advancement of fastener stock  11  through module  29 , which is highly desirable. 
     A ratchet wheel  111  is fixedly mounted onto shaft  107  and a pivotable feed pawl  113  is adapted to selectively engage ratchet wheel  111 . As such, the pivoting of feed pawl  113  serves to rotate ratchet wheel  111  which, in turn, drives feed wheels  105 , thereby disposing the lowermost fastener  18  in fastener stock  11  into position at the rear end of hollowed needles  75  for subsequent ejection. 
     Feed pawl  113  is, in turn, connected to a pivotable feed lever  115  and a movable feed link  117  by a bolt  118 . As can be appreciated, as ejector rod slide  85  completes its upward stroke, a bolt  119  engages feed link  117  and pulls feed link  117  upwards. The upward displacement of feed link  117 , in turn, causes feed pawl  113  to pivot about a pivot point  120  on feed lever  115 , thereby advancing fastener stock  11  through VNS module  29 . 
     It should be noted that the construction and functionality of feed mechanism  103  does not serve as a principal feature of the present invention. As a result, it is to be understood that feed mechanism  103  could be of the type disclosed in U.S. Pat. No. 5,615,816 to Charles L. Deschenes et al. without departing from the spirit of the present invention. 
     Severing Mechanism  121  for VNS Module  29   
     VNS module  29  additionally comprises a severing mechanism  121  for severing the lowermost fastener  18  from fastener stock  11  prior to ejection through neeedles  75 . Severing mechanism  121  comprises a pair of knife blades  123 - 1  and  123 - 2 , each blade  123  being pivotably disposed between an associated needle block  65  and needle holder  71 , as shown in FIG.  10 . 
     Severing mechanism  121  also comprises a pair of knife levers  125 - 1  and  125 - 2  connected to knife blades  123 - 1  and  123 - 2 , respectively. A pair spring-biased knife pivots  127 - 1  and  127 - 2  are connected to knife levers  125 - 1  and  125 - 2 , respectively. A pair of knife rollers  129 - 1  and  129 - 2  are connected to knife pivots  127 - 1  and  127 - 2 , respectively. As can be appreciated, knife rollers  129  are biased downward so as to continuously contact frame  39 . Accordingly, as ejector rod slide  85  begins its downward stroke, knife rollers  129  travel up and over ramp  95 . As knife rollers  129  travel up and over ramp  95 , knife rollers  129  pivot knife pivots  127  which, in turn, pull knife levers  125 . Resultingly, the pulling of knife levers  125  inwardly pivots knife blades  123 , thereby severing the lowermost fastener  18  from fastener stock  11 . It should be noted that spring-biased knife pivots  127  are designed only to pull knife levers  125  when as ejector rod slide  85  begins its downward stroke and not when ejector rod slide  85  completes its upward stroke. 
     It should be noted that the construction and functionality of severing mechanism  121  does not serve as a principal feature of the present invention. As a result, it is to be understood that severing mechanism  121  could be of the type disclosed in U.S. Pat. No. 5,615,816 to Charles L. Deschenes et al. without departing from the spirit of the present invention. 
     Retractable Needle Guard Assemblies  131  for VNS Module  29   
     VNS module  29  further comprises first and second retractable needle guard assemblies  131 - 1  and  131 - 2  which are disposed over first and second hollowed needles  75 - 1  and  75 - 2 , respectively. 
     It should be appreciated, the particular construction and functionality of retractable needle guard assemblies  131  serve as a principal feature of the present invention. In addition, it should be noted that first and second retractable needle guard assemblies  131 - 1  and  131 - 2  are identical in construction. As a result, for simplicity purposes only, the details of first and second needle guard assemblies  131 - 1  and  131 - 2  will be described only with respect to first needle guard assembly  131 - 1 . 
     First retractable needle guard assembly  131 - 1  comprises a fixedly mounted needle guard  133 - 1  which is affixed onto its associated needle holder  71 - 1  over needle  75 - 1  and a movable needle guard  135 - 3  which is slidably mounted on fixedly mounted needle guard  133 - 1 . 
     Referring now to FIGS. 11 and 13, fixedly mounted needle guard  133 - 1  comprises a base  137 - 1  in the shape of a half-disc which includes a substantially flat top surface  139 - 1  and a substantially flat bottom surface  141 - 1 . Base  137 - 1  also includes a central needle bore  143 - 1 , first guide pin bore  145 - 1 , second guide pin bore  147 - 1  and a pair of mounting screw bores  149  pre-formed therein pre-formed therein. 
     Fixedly mounted needle guard  133 - 1  further includes an elongated, C-shaped in lateral cross-section, inner sleeve  151 - 1  which is integrally formed onto and extends orthogonally out from bottom surface  141 - 1  of base  137 - 1 . Inner sleeve  151 - 1  includes an inner surface  153 - 1 , an outer surface  155 - 1  and a free end  157 - 1 , inner sleeve  151 - 1  being shaped to define an elongated central channel  159 - 1  which is sized and shaped to receive associated needle  75 - 1 , as shown in phantom in FIGS. 15 and 16. Outer surface  155 - 1  of inner sleeve  151 - 1  is shaped to include an enlarged flange  161 - 1  proximate free end  157 - 1 . 
     Referring now to FIGS. 11 and 14, movable needle guard  135 - 1  is slidably mounted over fixedly mounted needle guard  133 - 1  and comprises a collar  163 - 1  having a top surface  165 - 1  and a bottom surface  167 - 1 . Movable needle guard  135 - 1  also includes first and second guide pins  169 - 1  and  171 - 1  which are integrally formed onto and extend orthogonally out from top surface  165 - 1  of collar  163 - 1 , first and second guide pins  169 - 1  and  171 - 1  being sized and shaped to project into first and second guide pin bores  145 - 1  and  147 - 1 , respectively. First and second compression springs  173 - 1  and  175 - 1  are sized and shaped to be slidably mounted onto first and second guide pins  169 - 1  and  171 - 1 , respectively. 
     Movable needle guard  135 - 1  further includes an elongated, C-shaped in lateral cross-section, outer sleeve  177 - 1  which is integrally formed onto and extends orthogonally out from bottom surface  167 - 1  of collar  163 - 1 . Outer sleeve  177 - 1  includes an inner surface  179 - 1 , an outer surface  181 - 1 , a free end  182 - 1  and is shaped to define an elongated central channel  183 - 1  which is sized and shaped to receive inner sleeve  151 - 1  of fixedly mounted needle guard  133 - 1 . Inner surface  179 - 1  of outer sleeve  177 - 1  is shaped to include a stop  185 - 1 . 
     Accordingly, with needle  75 - 1  mounted onto needle holder  71 - 1 , with first end  77  of needle  75 - 1  fittingly disposed within its associated needle receptacle  78  in needle holder  71 - 1 , needle guard assembly  131 - 1  is mounted onto its associated needle holder  71 - 1  over its associate needle  75 - 1 . Specifically, top surface  139 - 1  of base  137 - 1  is disposed against the bottom surface of needle holder  71 - 1 . Screws  187  are then disposed through first and second mounting screw bores  149 - 1  and  151 - 1 , respectively, in base  137 - 1  and into engagement within associated threaded bores  188  formed in needle holder  71 - 1 , thereby fixedly securing needle guard assembly  131 - 1  onto needle holder  71 - 1  over needle  75 - 1 . 
     As can be appreciated, with needle guard assembly  131 - 1  mounted onto its associated needle holder  71 - 1  over needle  75 - 1 , each of first and second compression springs  173 - 1  and  175 - 1  is disposed to contact top surface  165 - 1  of collar  163 - 1  at one end and bottom surface  141 - 1  of needle holder  71 - 1  at the other end. As such, compression springs  173 - 1  and  175 - 1  resiliently urge collar  163 - 1  away from base  137 - 1 , thereby enabling for guard assembly  131 - 1  to be disposed between a protective position and retracted position. 
     With needle guard assembly  131 - 1  disposed in its protective position, as shown in FIG. 15, compression springs  173 - 1  and  173 - 2  urge collar  163 - 1  away from base  137 - 1  until enlarged flange  161 - 1  of fixedly mounted needle guard  133 - 1  abuts against stop  185 - 1  formed in movable needle guard  135 - 1 , thereby precluding further movement of movable needle guard  135 - 1  away from fixed needle guard  133 - 1 . With needle guard assembly  131 - 1  disposed in its protective position, free end  182 - 1  of movable needle guard  135 - 1  extends just beyond the sharpened tip of the needle  75 - 1 , thereby covering needle  75 - 1 . 
     With needle guard assembly  131 - 1  disposed in its retracted position, as shown in FIG. 16, an upward force greater than the force of the compression springs  173 - 1  and  175 - 1  is applied onto free end  182 - 1  of movable needle guard  135 - 1 , thereby displacing movable needle guard  135 - 1  upward relative to fixed needle guard  133 - 1  until top surface  165 - 1  of collar  163 - 1  is in contact against bottom surface  141 - 1  of base  137 - 1  and until free end  182 - 1  of outer sleeve  177 - 1  is substantially flush with free end  157 - 1  of inner sleeve  151 - 1 . With needle guard assembly  131 - 1  disposed in its retracted position, a fixed length of needle  75 - 1  is exposed. 
     As can be appreciated, retractable needle guard assemblies  131  provide three principal advantages. 
     As a first advantage, retractable needle guard assemblies  131  provide increased safety for the operator by preventing inadvertent contact of the sharpened point of hollowed needles  75  when VNS module  29  is not in use, which is highly desirable. 
     As a second advantage, retractable needle guard assemblies  131  serve as a stiffening, or support, device for needles  75 , thereby preventing needle bending and/or breakage, which highly desirable. 
     As a third advantage, retractable needle guard assemblies  131  serve as a needle stop for limiting the depth which needles  75  can be inserted through display card C. Specifically, needle guard assemblies  131  limit the length of needle  75  which can be inserted through display card C to a fixed constant length. In particular, the portion of each needle  75  from the sharpened tip at second end  79  to free end  182  of outer sleeve  177  is able to penetrate through display card C when needle guard assemblies  131  are in their retracted position. It should be noted that a constant degree of insertion of needles  75  through display card C is highly desirable because if needles  75  are over inserted through display card C, fastener  18  can become overstretched and will break during ejection, which is highly undesirable. Furthermore, if needles  75  are under inserted through display card C, fastener  18  will not adequately penetrate through display card C, thereby precluding proper coupling, which is highly undesirable. 
     Mounting Stand for  31  System  10   
     Mounting stand  31  is installed onto workstation W and supports counterbalance  33  and reel holder  35 . 
     Referring now to FIGS. 17 and 18, mounting stand  31  is generally L-shaped and includes a vertical leg  187  and a horizontal leg  189  which are affixed together. 
     Vertical leg  187  is substantially straight and includes a first end  191  and a second end  193 . A flat support plate  195  is affixed onto first end  191  of vertical leg  187 . Flat support plate  195  is shaped to include a plurality of preformed holes  197 . As such, a screw  199  can be disposed through each preformed hole  197  in support plate  195  and down into engagement into workstation W so as to fixedly secure vertical leg  187  onto workstation W, vertical leg  187  extending orthogonally from the top surface of workstation W. 
     Horizontal leg  189  is substantially straight and includes a first end  201  and a second end  203 . A projection  205  is formed onto first end  201  of horizontal leg  189  and is sized and shaped to fit within a slot  207  formed in second end  193  of vertical leg  187 , as shown in FIG. 18. A screw  209  is disposed through an opening  211  formed in second end  193  of vertical leg  187  and into threaded engagement within an opening  213  in projection  205  of horizontal leg  189  so as to fixedly secure horizontal leg  189  onto vertical leg  187  in such a manner that horizontal leg  189  extends generally orthogonally from vertical leg  187 . 
     Counterbalance  33  for System  10   
     Counterbalance  33  is affixed onto mounting stand  31  and serves to support VNS module  29 . 
     Referring now to FIG. 19, counterbalance  33  includes a box-shaped housing  215  and a U-shaped bracket  217  affixed onto housing  215 , U-shaped bracket  217  being shaped to includes a pair of openings  219 . A pin  221  is sized and shaped to be disposed through openings  219  in U-shaped bracket  217  and through an opening  223  formed in horizontal leg  189 , thereby securing counterbalance  33  onto horizontal leg  189 . A cotter pin  225  is sized and shaped to be slidably disposed through an opening (not shown) formed in pin  221 , so as to retain pin  221  through U-shaped bracket  217  and opening  223  in horizontal leg  189 . 
     Counterbalance  33  is conventional in construction and includes a tether  227  which is wound within housing  215  and which includes a free end  229  disposed outside housing  215 . As can be appreciated, free end  229  of tether  227  can be pulled away from housing  215 . However, in the absence of the pulling force, tether  227  resiliently pulls free end  229  back to housing  215 , a stop  231  proximate free end  229  limiting the retraction. A clip  233  is formed onto free end  229  of tether  227  and is sized and shaped to releasably dispose into and engage clip opening  59  in bracket  49 . 
     Reel Holder  35  for System  10   
     Reel holder  35  is affixed onto mounting stand  31  and serves to support reel  27  of fastener stock  11 . 
     Referring now to FIG. 20, reel holder  35  is in the form of a stiffened wire and comprises a first end  235  and a second end  237 . 
     First end  235  of reel holder  35  is sized and shaped to extend horizontally through a central opening  28  formed in reel  27 , thereby enabling reel holder  35  to support reel  27  of fastener stock  11 . A pair of retainer clips  239  are sized and shaped to fixedly mount onto first end  235  of reel holder  35  on opposite sides of reel  27 , thereby securing reel  27  onto first end  235  of reel holder  35  but enabling reel  27  to rotate on reel holder  35  without interference. 
     Second end  237  is sized and shaped to extend vertically down into a reel holder opening  241  formed into horizontal leg  189 . As such, reel holder  35  supports reel  27  from horizontal leg  189  of mounting stand  31 , as shown in FIG.  1 . 
     Anvil  37  for System  10   
     Anvil  37  is mounted onto workstation W and serves to support product P and display card C during the fastening process. 
     Referring now to FIG. 2, anvil  37  preferably comprises a support block  243  and a plurality of filaments  245  disposed into support block  243 . 
     Support block  243  is preferably constructed of polyvinyl chloride (PVC) and comprises a substantially flat top surface  247 , a substantially flat bottom surface  249  and four sidewalls  251 . Support block  243  has a length of approximately 4.0 inches, a width of approximately 4.0 inches and a thickness of approximately 0.75 inches. 
     A plurality of openings (not shown) are formed into top surface  247  of support block  243  and extend down a portion of the distance from top surface  247  towards bottom surface  249 . Each opening is generally circular in lateral cross-section with a diameter of approximately 0.098 inches. A tuft of nylon brush filaments  245  is disposed into each opening to form anvil  37 . 
     Operation of System  10   
     In use, system  10  can be used to affix a product for sale P onto a display card C using one or more plastic fasteners  18  from fastener stock  11  in the following manner. Display card C is placed on top of filaments  245  of anvil  37  and product P for sale, in turn, is placed on top of display card C, as shown in FIG.  2 . The user then grasps handle  45  of VNS module  29  and urges it downward so that needles  75  pierce through display card C, needles  75  being disposed on opposite sides of product P for sale. Needles  75  are disposed through display card C and down between filaments  245  of anvil  37 . It should be noted that VNS module  29  is urged downward until needle guard assemblies  131  are in their fully retracted position. As such, needle guard assemblies  131  serve to accurately limit the degree of insertion of needles  75  through display card C, which is highly desirable. With needles  75  disposed through display card C and with needle guard assemblies  131  disposed in their fully retracted position, actuation button  97  is depressed so as to eject a single fastener  18  out through needles  75 . The ejection of single fastener  18  disposes end bars  19  and  21  on the opposite side of display card C than product P, filament  23  of fastener  18  being drawn tightly against product P so as to securely couple product P to display card C, as shown in FIG.  3 . 
     The process can be repeated as necessary, wherein a subsequent depression of actuator button  97  ejects another fastener  18  out through needles  75 . Accordingly, because a continuous supply of fastener stock  11  can be loaded into VNS module  29 , it is to be understood that system  10  can be used to continuously apply fasteners  18  without reloading. 
     It should be noted that counterbalance  33  enables VNS module  29  to be easily handled by the user during high volume packaging operations, such as assembly line packaging, which is highly desirable. Furthermore, it should be noted that supporting VNS module  29  onto counterbalance  33  is made possible by providing anvil  37  and needle guard assemblies  131  on VNS module  29  to ensure that fastener  18  is properly disposed through display card C. 
     The embodiment shown in the present invention is intended to be merely exemplary and those skilled in the art shall be able to make numerous variations and modifications to it without departing from the spirit of the present invention. All such variations and modifications are intended to be within the scope of the present invention as defined in the appended claims.