Abstract:
An electrostatic discharge (ESD) garment having a pair of sleeves ( 10 ) which provides elastic contact between the wrists of a wearer and said sleeves ( 10 ), wherein each of said sleeves ( 10 ) comprising of a pair of attachment means ( 12 ) provided on the sleeve in such a manner that it creates a space gap ( 14 ) provided in between the attachment means ( 12 ) for receiving an elastic wrist band ( 11 ) looped thereon to enable the formation of a pocket when said sleeve ( 10 ) is folded with proper alignment to enable said first attachment means ( 12   a ) attached and hold together with said second matching attachment means ( 12   b ).

Description:
FIELD OF INVENTION 
       [0001]    The present invention relates to a static dissipative coat-like outer garment, more particularly to an ESD (Electrostatic Discharge) smock which provides excellent and reliable static dissipative and contamination protection. 
       BACKGROUND OF INVENTION 
       [0002]    A static dissipative or ESD smock is commonly used in electronic devices manufacturing environment to drain static charges from the operation personnel. It is also important that such ESD smock ideally be groundable so as to enable any static charge that may be floating or residing on the ESD smock generated through the personnel&#39;s movement or transferred from the inner clothing by static charge induction be drained away when the ESD smock is grounded. The pathway in which these electrostatic charges are drained from the ESD smock can be through a groundable point strategically located a certain spot or area of the smock as highlighted in U.S. Pat. No. 5,548,469 or through sleeve collar of such ESD smock as highlighted in the PCT Application No. PCT/MY2009/000061 and WO2009139617. 
         [0003]    Japan publication JP2000178810 A with its representative drawing in fig A (1) highlights an antistatic garment with electroconductive fiber that brought into contact with pressure (elastic band) to the wrist of a human body. 
         [0004]    However, when the band is loosen due to “deform” from continuous stretching during daily use, periodic laundering &amp; heat drying, etc. the whole smock need to be replaced due to intermittent failure or lost in electrical contact at the cuff. 
         [0005]    U.S. Pat. No. 4,596,053 with its representative drawing in fig A (2) highlights how a conductive band that encircles the wrist is attached to the sleeve opening of a smock electrically through the use of fastener (metal snaps). 
         [0006]    However, if the worker “forgets” to snap on the metal snap, body to ground system fails. 
         [0007]    U.S. Pat. No. 4,868,710 with its representative drawing in fig A (3), a garment is formed with a conductive wrist band (18) sewn onto the cuffs of the garment (12). In FIG. 5, wrist band (08) is shown as having snap 32 and 34 which can tighten wrist band (18) around the wrist of a person. 
         [0008]    However, if the worker “forget” to snap on the snaps together, body to ground system fails. 
         [0009]    A typical ESD smock which is worn and ground through the sleeve collar, have its sleeve collar tightly and comfortably wrapped around the wrist of the personnel by means of an in-sewn elastic band.  FIG. 1  shows the use of such a technique in the a applicant&#39;s previous PCT application on an improved ESD smock (application No. PCT/MY2008/000048). 
         [0010]    Apart from ensuring good contact between the wrist of the wearer and the sleeve of the smock, the comfortably and tightly fit sleeve collar design also ensures that any foreign contamination is prevented from falling out from the sleeve or the body or inner clothing of the personnel to the electronic assembly area. 
         [0011]    However, there are various shortcomings from using such typical elastic band sleeve collar smock. As rubber elastic bands tend to deteriorate and loosen overtime. This is because under constant stretching of the elastic band during daily use, periodic laundering and under repeated stretching from wearing and undressing the smock, the elastic rubber band will deform and loose its elasticity overtime. When this happened, the smock is no longer effective in its electrical contact with the wearer especially in a dry relative humidity assembly manufacturing environment. This will result in non-reliable ESD protection as the pathway for charge drainage is now intermittently broken. Apart from that, when the sleeve collar becomes loosen, there might be tendency for foreign contaminants to fall off from the inner clothing or the body of the personnel and contaminate the electronic work assembly area. 
         [0012]    This problem further compounded when the smock is repeatedly worn by a person with a relatively larger wrist size and later worn by a person with a smaller wrist size. The elastic band may be over stretched by the former person. On top of that, persons wearing the same size smock can be very different sizes in their wrist lines, causing unwanted logistic problem in distributing the right sized ESD smock to the personnel in a labour-intensive electronics manufacturing environment. 
         [0013]    The key factor in this problem is that it will not be known when this failure in sleeve contact will happen. This makes the current smock design very unreliable as such failure can occur anytime during the production operation. Putting in a continuous monitoring system of the ESD protection of the smock will further dramatically increase the operation cost of a highly competitive and cost conscious electronics assembly operations. 
         [0014]    For those skilled in the art, an apparent solution would be to search for a more durable or better elastic rubber band. However, this will only serve to prolong the lifespan of the rubber band and it is not an effective solution to the problem. The uncertainty of failure occurrence is still prevalent especially in dry relative humidity environment and those operation personnel or wearers with dry skin. 
         [0015]    Therefore, there is genuine demand and industrial need to find a more workable and practical solution with a more economical means yet able to guarantee grounding integrity and reliability. This led to further research to provide a more reliable and failure-proof feasible solution. 
         [0016]    Other objects of this invention will become apparent on the reading of this entire disclosure. 
       SUMMARY OF THE INVENTION 
       [0017]    The present invention consists of a replaceable elastic wrist band that can easily attach and remove from the sleeve of a smock with the helps of a pair of attachment means preferably a pair of Velco tapes. The objective is to extend the durability and usable shelf-life of an ESD smock to achieve economic advantage and commercial attractiveness. 
         [0018]    Such interchangeable elastic wrist band can be attached or looped onto the sleeve in various means through the use of Velco tapes, snap-on buttons, standard buttons or zipper type fastener, etc. The most preferred means is the Velco tape. 
         [0019]    In the first embodiment of the present invention, a pair of Velco tapes is sewn onto the outer side of the sleeve of a smock in such a manner that it provides a space gap for receiving an elastic wrist band looped over the sleeve at the space gap in between the pair of Velco tapes. When the sleeve is folded outwards, the pair of Velco tapes is properly assigned and hold together to form a pocket for enclosing the elastic band therein so as to form a smock with replaceable elastic sleeve. 
         [0020]    Alternatively in the second embodiment, an additional piece of flap is sewn onto the sleeve in such a way to allow formation of a pocket to enclose the elastic band. Thus various sizes of the elastic rubber band can be easily placed into the pocket and simply sealed-up by the Velco band at ease. This simple design also ensures that the rubber band can be easily replaced as and when needed, eliminating the need to replace the complete ESD smock thereby achieving attractive cost saving in daily real-life use. 
         [0021]    The invention achieves an easy-to-manage automatic fail-proof compliance system. Once the correct size of the elastic band is chosen for a worker, there is no further or special instruction to him/her is required. Workers just put on the smock and use. That&#39;s all. This solves the problem of the needs to have more monitoring and control over the worker&#39;s body-to-ground grounding system and simplifies ESD control procedure. This invention is especially useful in a labour intensive assembly operations in a typical electronics manufacturing industry. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    Other objects, features, and advantages of the invention will be apparent from the following description when read with reference to the accompanying drawings. In the drawings, wherein like reference numerals denote corresponding parts throughout the several views; 
           [0023]      FIG. 1  depicts a partial perspective view of a hand with the ESD smock of the prior art; 
           [0024]      FIG. 2  shows the illustrations of an ESD smock with interchangeable elastic bands of the first embodiment of the present invention which are shown in  FIGS. 2   a  to  2   c;    
           [0025]      FIG. 3  shows the illustrations of an ESD smock with interchangeable elastic bands of the second embodiment of the present invention which are shown in  FIGS. 3   a  to  3   c ; and 
           [0026]      FIG. 4  shows the illustrations of different kinds of elastic wrist bands of the present invention which are shown in  FIGS. 4   a  to  4   c.    
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0027]      FIG. 2  shows the end-most portion sleeve ( 10 ) of an electrostatic dissipative smock having a replaceable elastic wrist band ( 11 ) of the first embodiment of the present invention. A pair of attachment means ( 12 ) with its first attachment means ( 12   a ) located adjacent to the end-most opening ( 13 ) of the sleeve ( 10 ) and its second matching attachment means ( 12   b ) located at a distance away from the first attachment means ( 12   a ) of the sleeve ( 10 ), thereby providing a space gap ( 14 ) in between the first ( 12   a ) and second ( 12   b ) attachment means to allow the elastic wrist band ( 11 ) to be looped over thereon. The attachment means ( 12 ) could be any suitable attachment means that are able to attach together for enclosing the wrist band( 11 ) at the space gap ( 14 ) such as Velco tapes, snap-on buttons, standard buttons, zipper type fastener, etc. For the zipper type fastener, it consists of a pair of interlocking components that enabling resealing and unsealing of the fastener. The preferred attachment means ( 12 ) used for the present invention is the Velco tapes and for illustration purposes, this type of attachment means ( 12 ) will be further described. 
         [0028]    The first and second attachment means ( 12   a ,  12   b ) of the Velco tapes type of attachment are the male and female tapes respectively. The first attachment means ( 12   a ) is sewn onto an external side adjacent to the end-most opening ( 13 ) encircling the sleeve ( 10 ) and the second attachment means ( 12   b )is also sewn onto the external side at a distance away from the first attachment means ( 12   a ) encircling the sleeve ( 10 ) as shown in  FIG. 2   a . The elastic wrist band ( 11 ) is then looped over the sleeve ( 10 ) at the space gap ( 14 ) of the sleeve ( 10 ) as shown in  FIG. 2   b.    
         [0029]    The pair of attachment means ( 12 ) is attached together by outwardly folding the end-most portion of the sleeve ( 10 ) to bring the first attachment means ( 12   a ) to the second attachment means ( 12   b ) and with proper alignment to be pressed on to enable them to hold together for forming a pocket as shown in  FIG. 2   c . The elastic wrist band ( 11 ) is enclosed within the pocket of the sleeve ( 10 ) to form an elastic sleeve smock of the present invention. 
         [0030]    At the discretion of an user, different width of the elastic rubber band can be used to achieve desirable strength suitable for use by every individual wearer. The elastic wrist band ( 11 ) enclosed inside the sleeve can be easily changed due to its unique design to suit the wrist-size of a wearer. The elastic band ( 11 ) can be made of natural or synthetic rubber or mixture of materials to provide the proper elasticity. 
         [0031]    The present invention allows elastic rubber bands of different circumference to be inserted into the pocket. This is to accommodate for different wrist sizes. This inventive feature is very important as the prior arts which adopts a one-size-fits-all design often utilizes elastic rubber bands of fixed circumference. When the smock is worn on a relatively larger wrist of a person, this will tend to over-stretched the rubber band and thus reducing the elasticity and lifespan of the rubber band. This reduces the reliability of the smock. As the insertion and removal of the elastic rubber band in the current invention can be done easily due to the unique design of the sleeve, the elastic rubber band can be replaced periodically. The frequency in replacing these elastic rubber bands can then be arranged as part of operation maintenance before any possible failure can occur. This is essence solves the problem currently prevalent in the prior arts. 
         [0032]    In another embodiment of the present invention, an additional piece of flap ( 15 ) is attached to the sleeve ( 10 ) as an alternative option to create a pocket for enclosing the elastic wrist band ( 11 ). It can be done by having the flap ( 15 ) sewn in circular ring onto the sleeve ( 10 ) located at a predetermined distance from the end-most opening of the sleeve ( 10 ) as shown in  FIG. 3   a . A pair of Velco tapes ( 12 ) is then sewn in similar manner as before to provide a space gap ( 14 ) with the complementing faces facing inwards towards each other. These tapes ( 12 ) can be pressed and attached together to form a pocket for enclosing the elastic wrist band ( 11 ) which is looped over the sleeve ( 10 ) at the space gap ( 14 ) as shown in  FIGS. 3   b  and  3   c . This is essentially an add-on collar at the sleeve to provide an optional means to achieve the same objective of a replaceable wrist-band of the current invention. 
         [0033]    Alternatively, the two methods of applications as described above can be applied to the internal (reverse) side of the sleeve of such ESD garment. In order to enable the end-most opening ( 13 ) of the sleeve ( 10 ) be folded inwardly and hidden inside the sleeve when said garment is worn by the wearer, a pair of attachment means ( 12 ) is sewn onto the internal side adjacent the end-most opening ( 13 ) encircling the sleeve ( 10 ) as shown in  FIG. 4   a , or onto an additional piece of flap ( 15 ) which is attached to the internal side (not shown) of the sleeve ( 10 ) to create a pocket for enclosing the elastic wrist band ( 11 ). 
         [0034]    In order to put on the elastic wrist band ( 11 ) onto the sleeve ( 10 ) before wearing the garment, the wearer may overturn the sleeve ( 10 ) of the garment inside out to enable the elastic wrist band ( 11 ) to be looped over the sleeve ( 10 ) at the space gap ( 14 ) with ease. The pair of attachment means ( 12 ) is then attached together by inwardly folding the end-most portion of the sleeve ( 10 ) to form a pocket as shown in  FIG. 4   b . The wrist band ( 11 ) is enclosed within the pocket of the sleeve ( 10 ) as shown in  FIG. 4   c.    
         [0035]    All the shortcomings of the prior arts were overcome by the new smock design which provides a fool-proof and reliable ESD protection economically. In general, although this invention has been described in connection with specific forms and embodiment thereof, it will be appreciated that various modifications other than those discussed above maybe resorted to without departing from the scope of the invention. 
         [0036]    As will be readily apparent to those skilled in the art, the present invention may easily be produced in other specific forms without departing from its essential characteristics. The present embodiments is, therefore, to be considered as merely illustrative and not restrictive, the scope of the invention being indicated by the claims rather than the foregoing description, and all changes which come within therefore intended to be embraced therein Claims.