Abstract:
The present invention provides a kind of clip fastener for attaching gaskets or gasket-like devices to a mounting surface, including a mounting surface engagement head, a neck and a protrusive base perpendicular to the plane of the head and attached to the neck. The present invention also presents a kind of method and equipment for mounting a clip fastener with protrusive base to gasket. Clip fastener base in present invention can be embedded into gasket, or rotated into woven gasket, or embedded into gasket being weaving. The head extend outwards across gasket and clip fasteners in the holes on mounting surface to fasten gasket to mounting surface firmly and effectively.

Description:
FIELD OF TECHNOLOGY 
     The present invention covers a new kind of clip fastener for attaching gaskets or gasket-like devices to a mounting surface especially those for oven gasket, and a method of mounting this clip fastener to gasket and corresponding equipments. 
     BACKGROUND OF TECHNOLOGY 
     The doors of ovens, refrigerators and microwaves etc. have tubular gaskets around their perimeter for sealing and a variety of other reasons. This gasket is typically made of a combination of an inner tubular support member formed of knitted wire and an outer tubular member made either by braiding, knitting or weaving an insulating material such as fiberglass yarn. Such structures have proven to be durable at high temperatures used in self-cleaning ovens and provided a good sealing despite repeated openings and closures of the oven door over many years of use. 
     Methods of attaching a tubular gasket to oven door surface have typically comprised of providing several individual clip fasteners which extends along the gasket axial. Clip fasteners have heads and bases which are perpendicular to one another. Bases are embed into the gasket while heads projected out from gasket and inserted into the hole of the oven door to mount the gasket onto the oven door. 
     Several clip fasteners are presented in prior arts. For example, U.S. Pat. No. 6,893,025 presents a kind of gasket apparatus with clip fasteners. A clip fastener coming from a strand of elastic metal wire bent in a certain angle includes a diamond-shaped head and a base which is perpendicular to the plane of the head. The base comprises at least one coil course having a variable or constant radius of curvature and one tail. The tail typically bents downwards and separates from the last coil course. During many years of use, it is found that hands of operator are easily to be pricked when mounting gasket because of the up-wrapped tail. In addition, fiberglass is also easily to be pierced or lacerated which causes bad performance of gasket. Furthermore, as there is a tail in the clip, it is hard to be embedded into gasket when weaving. It has to be embedded into woven gasket by rotating and it is labor intensive process. When the base of clip fastener is more than one loop coil course, the multi-coil will easily cause the silk-spinning of fiberglass and affect sealing. 
     U.S. Pat. No. 5,107,623 presents a kind of loom-type weaving clip fastener which avoids intensive labor when rotating the clip fastener into gasket, but it brings another problem. As soon as the clip fastener is woven into gasket, it is hard to extract it again unless forced extraction. However, forced extraction will destroy the woven structure of fiberglass and bring heavy affection to sealing. When using this kind of clip, if any step is taken incorrectly, for example, wrong separation between clip fasteners or clip fasteners not in a line, total gasket will be rejected. 
     When mounting clip fasteners to gasket, clip fastener is mounted to gasket when fiberglass sheath is being woven. For example, in U.S. Pat. No. 6,533,289, an equipment for weaving fiberglass sheath weaves fiberglass sheath mounting clip fastener while weaving fiberglass sheath. In existing arts, most equipments take simple change or manual operation based on the equipment for weaving fiberglass sheath and the efficiency is low. 
     SUMMARY OF THE INVENTION 
     Present invention presents a kind of improved clip fastener for attaching gaskets or gasket-like devices to a mounting surface which can not only be rotated into woven gaskets, but also be embedded firmly while weaving. 
     This kind of clip fastener for attaching gaskets or gasket-like devices to a mounting surface consists of a single strand of resilient and bendable wire made of metal or other suitable materials. It includes a mounting surface engagement head, a neck and a base perpendicular to the plane of the head and connected to the neck. The head has an apex and a pair of shoulders. The shape of shoulders is typically symmetrical and the head extends from apex to shoulders. One of the shoulders twist into an end of the wire and the other one twists inwards to be an adjacent point to the end of wire. The thinnest portion of the shoulder is a neck. Other wire is a little tilted skew downwards from the neck and helically winds into the base. The neck locates over the plane of base and is protrusive. The longitudinal axis of the apex and neck is perpendicular to the base. 
     The coiled base is perpendicular to the plane of head and there is a protrusion on the ending portion of loop. The plane defined by protrusions is perpendicular to base. The other end of the wire is the terminal of protrusions. A subtle space is left near the coiled base and in the same plane of base. 
     A further embodiment of present invention is as follows: the plane defined by the protrusion on the coiled base is parallel to that of head and perpendicular to the base; or there are two protrusions on loop which define two planes parallel to that of head and perpendicular to the base. 
     As a further embodiment, one shoulder twisted to be an end of the wire, bends at the neck and transversely extend to form a transverse extension. 
     Transverse extension mentioned above is approximately parallel to the plane of coiled base and can, together with base, press the wall of an inner tubular support member closer to that of an outer tubular support member. 
     Length of transverse extension is ⅓˜⅔ part of the radius of base and the optimum factor is ½. Keeping an appropriate length for transverse extension to fit base can press the wall of inner tubular support member closer to that of outer tubular support member, which can also save materials and avoid scraping the outer tubular member during mounting. 
     Restriction of transverse extension and base eliminates the gap between the inner tubular support and the outer tubular support. When mounting the clip fastener, transverse extension will prevent the head to be squeezed into neither the inner tubular support nor the outer tubular support. 
     Present invention also provides a method of mounting a clip fastener with a protrusive base to a gasket. The steps are as follows: 
     (a) Tightly grasping the head of clip fastener 
     (b) Squeezing the protrusion of base to separate the end of base from base plane. 
     (c) Extending gasket and clip fastener toward one another until end of clip fastener base is inserted into gasket. 
     (d) Rotating clip fastener around the axis defined by apex of head and neck to insert base into gasket. 
     Present invention also provides an equipment to realize the method above. This equipment can rotate the base of clip fastener into a composite gasket made of metal wire framework and fiberglass through a rotatable nose grasping clip fastener head. It can mount clip fastener to gasket automatically and rapidly. 
     The equipment for mounting a clip fastener with protrusive base to gasket comprise of: rack designed with several rotatable noses and one gasket apparatus which can move in relation to noses back and forth alternatively. Heads mentioned above has a narrow channel to locate the head of clip fastener at the front part. The narrow channel divided the front part into two parts. One part in relation to the other part along the nose axis has axial protrusions used to squeeze the protrusions of the base of clip fasteners. Gasket apparatus comprises groove and squeezing block in the grove used to squeeze gasket. On the lateral wall of groove towards heads is back plate. There are several side openings on a back plate used to pass clip fasteners. When the gasket apparatus moves and reaches noses, the gasket is rotated into the base by the noses. 
     In order to adjust the gap between clip fasteners in the gasket, there is a rail parallel to the groove of gasket apparatus on the rack mentioned above. Several heads are fixed on rail by respective nose base. The distance between nose bases is adjustable and fastened to the rail by screw. Herein nose is multidiameter and has an impetus converter at the end of itself. 
     With respective impetus converter, herein all several noses are connected to a motor-drive main shaft. There are several impetus output blocks on a main shaft working together with the impetus converters of the noses. 
     Impetus converter of heads and impetus output block are gears engaging to each other. The main shaft drives respective heads through impetus converter of heads and impetus output block. 
     Several rails used to support gasket apparatus are designed on the rack. At the bottom of the gasket apparatus, there are several drive arms connected to and driven by drive apparatus, to move gasket apparatus back and forth alternatively along rail. 
     At the rack along which the gasket apparatus reciprocates, the first photosensor and second photosensor are located at the end of the rack, respectively, to monitor the position of gasket apparatus. When the gasket apparatus approaches the nose, first photosensor sends out an electrical signal to rotate the nose. When the gasket apparatus return to initial position, the second photosensor sends out an electrical signal to reverse the nose. 
     The gasket apparatus also includes a groove cover hinged with a lateral wall of groove. At one end of the groove cover and one end of the groove, there is a piece of blade, respectively. When the groove cover is closing towards the groove, the blades on the groove cover and the groove engage together to cut off gaskets in the groove. 
     The grip block used to fasten gasket ends is designed at one end of gasket apparatus. One end of grip block is mounted in groove by a pin roll and a hand knob is mounted to the center potion of grip block by a connecting rod. 
     One end of main shaft is connected to an adjusting revolving tray to control the rotation angle of every nose. The angle of every narrow channel of noses can be adjusted by revolving tray thus to make all narrow channel horizontal for easy mounting of the clip. 
     For the sake of automatic control, the drive apparatus, used to rotate nose and move gasket apparatus and to move back and forth alternatively, can be inserted into a control apparatus, together with the first photosensor and second photosensor of gasket apparatus to implement automatic control. 
     For clip fasteners embedded to a gasket, its base is completely in the cavity between tubular gaskets. Its head extends out from woven sheath of gasket. There is a sharp apex in the head of clip fastener which can be inserted to the hole about 3.9 mm wide on the door of oven. Two shoulders shrink due to pressure from the hole, which make the head easy to cross the hold on the door of oven. When the head passes the hole, the shoulders recover the initial size. Because the distance between the two shoulders is larger than the hole, the head of the clip fastener can be clipped in the hole of the oven, and the gasket is mounted on the door of the oven. 
     The structure of clip fastener in present invention is simple and effective. Protrusions on base ensure a firm and effective attaching of gasket and mounting surface. The neck separated from the plane of base ensures that clip fasteners can be rotated out easily from gasket without damage to woven structure. Furthermore, one end of metal wire on base is in the same plane of base and has no up-wrapped tail, which prevents the metal wire of clip fasteners from pricking fiberglass and hands of operator during mounting. Using method and equipment in present invention to mounting clip fasteners can dramatically improve the efficiency of mounting and realize the automation of clip fastener mounting. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a three-dimensional figure of the clip fastener in present invention. The protrusions locate at the end of coiled base. 
         FIG. 2  is front view of clip fastener in  FIG. 1 . 
         FIG. 3  is a three-dimensional figure which depicts a second embodiment of clip fastener in present invention. The protrusions locate far from the end of coiled base. 
         FIG. 4  is a three-dimensional figure which depicts a third embodiment of clip fastener in present invention. There are two protrusions parallel to the head in the coiled base. 
         FIG. 5  is a three-dimensional figure which depicts a forth embodiment of clip fastener in present invention. The neck has transverse extension. 
         FIG. 6  is a three-dimensional figure which depicts a fifth embodiment of clip fastener in present invention. The neck has transverse extension and there are two protrusions parallel to the head in the coiled base. 
         FIG. 7  is a structure sketch of clip fastener base protrusions deformation after squeezed. 
         FIG. 8  is a structure sketch of clip fastener mounting equipment in present invention. 
         FIG. 9  is a structure sketch of noses in clip fastener mounting equipment in present invention. 
         FIG. 10  is a structure sketch of grip block in clip fastener mounting equipment in present invention. 
         FIG. 11  is a partial three-dimensional structure sketch of clip fastener mounting equipment in present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Embodiment Example Clip Fastener with Protrusions on Base 
     As  FIG. 1  and  FIG. 2  depicted, one kind of clip fastener for attaching gaskets or gasket-like devices to a mounting surface, consists of a single strand of resilient and bendable wire make of metal or other suitable materials, typically stainless metal such as 304ss semi-rigid stainless metal. The cross section of metal wire is typically orbicular with a diameter of 0.5˜0.8 mm, typical value is 0.635 mm. The clip fastener includes a mounting surface engagement head  201 , a neck  202  and a base  207  perpendicular to the plane of the head and connected to the neck. The head  201  has a sharp apex  204  and a pair of shoulders  205 . The shape of shoulders is typically symmetrical and the head  201  extends from apex  204  to shoulders. One of the shoulders twist into an end  206  of the wire and the other one twists inwards to be an adjacent point to the end  206  of wire. The thinnest portion of shoulder is neck  202 . The remainder wire is a little skew downwards from neck  202  and helically winds into base  207 . Neck  202  locates 0.8˜1.0 mm over the plane of base  207 . The longitudinal axis of the apex  204  and neck  202  is perpendicular to the base. Coiled base  207  is perpendicular to the plane of head  201  and there is a protrusion  208  on the ending potion of loop. The plane defined by protrusions is perpendicular to base. The other end  209  of wire is the terminal of protrusions close to the beginning  210  of coiled base but 0.3˜0.4 mm spaced and it is in the same plane of base. 
     The protrusion of clip fasteners in this embodiment is 1.0-1.5 mm and 4.0-5.0 mm long (from the beginning of protrusion to the termination). 
     The optimized size of the head of clip fastener in this embodiment: the vertical distance between base  207  and shoulders  205  is about 3.3 mm, the distance between base  207  and apex  204  of the clip fastener is about 10.4 mm, the width between the shoulders is about 4.8 mm, the height of the protrusion is 1.5 mm and the length of it is 4.5, and the vertical distance between base  207  and neck  207  is 1.0 mm. 
     Embodiment Example 2 
     The Second Kind of Clip Fastener with Protrusions on Base 
       FIG. 3  depicts another embodiment of the clip fastener in present invention. The plane defined by protrusions  208  is parallel to the plane of head  201  and perpendicular to base  207 . The protrusion locates far from the terminal of the base loop and on another side of the end of coiled base. 
     The best size of clip fastener in  FIG. 1  is also applicable to the clip fastener in this embodiment. 
     Embodiment Example 3 
     The Third Kind of Clip Fastener with Protrusions on Base 
       FIG. 4  depicted another improved kind of clip fastener whose base  207  loop has two protrusions  208   a  and  208   b . The planes defined by these two protrusions are parallel to head  201  and perpendicular to base  207 . 
     It is better for the clip fastener with two protrusions when mounting: first rotating the clip fastener into inner tubular support and then weaving fiberglass sheath around the clip fastener thus to improve the automation. 
     Embodiment Example 4 
     The Forth Kind of Clip Fastener with Protrusions on Base 
     As a further embodiment, except the protrusion  208  on base, one shoulder twisted to be an end  206  of the wire and this end  206  of wire bends at the neck  202  and transversely extend to form transverse extension  211 . 
     Transverse extension  211  is approximately parallel to the plane of coiled base  207  and can pressed the wall of inner tubular support member closer to that of outer tubular support member together base  201 . Length of transverse extension  211  is ½ part of the radius of base and. An appropriate length for transverse extension  211  fitting with base  207  can press the wall of inner tubular support member closer to that of outer tubular support member thus the material is saved and outer tubular support will not be scraped. 
     Embodiment Example 5 
     The Fifth Kind of Clip Fastener with Protrusions on Base 
     In this embodiment, the base has two protrusions  208   a  and  208   b . The end of wire  206  bends at the neck  202  and transversely extends to form the transverse extension  211 . 
     The clip fastener in present invention also has many variations and modifications. The detailed structure is not only limited to the embodiment mentioned above. For example, except hemicycle, the protrusion can also be trapeze or other shape; protrusions can locate anywhere around the base; number of protrusions can be increased or decreased if required. In general, present invention also intends to cover any easy modifications for the technologist. 
     Embodiment 6 
     Method of Mounting 
     A method of embedding clip fasteners into gasket is as follows: as there is a gap of 0.3˜0.4 mm between the terminate of coiled base, i.e. one end of metal wire  209  and the beginning  210  of coiled base, it is helpful to separate the end of wire  209  from the base  207  by pressing protrusion. First the end of wire  209  is inserted into woven sheath, and then pressed into woven sheath and rotated it until it hangs on some wire in the inner tubular support of gasket. After that, the clip fastener is rotated around the longitudinal axis of apex  204  and neck  202 . Then the base  207  will cross woven sheath and inner tubular metal support and thereafter is fully under the metal wire of inner tubular support. 
     Steps of mounting clip fastener in present invention to gasket: 
     (a) Tightly grasping the head ( 201 ) of clip fastener 
     (b) Squeezing the protrusion  208  of base  207  to separate the end of base from base, see  FIG. 7 . 
     (c) Extending gasket and clip fastener toward one another until the end  209  of clip fastener base is inserted into gasket. 
     (d) Rotating clip fastener around the axis defined by apex  204  of head and neck  202  to insert base  207  into gasket. 
     All the clip fasteners depicted in  FIG. 1˜6  can be mounted by adopting the method mentioned in present invention. In addition, the clip fastener also has many variations and modifications. The detailed structure is not only limited to the embodiment mentioned above. For example, how to fasten the head of clip fastener and what equipment to be used is variable depending on current technology. When squeezing the protrusions on base, more than one tool or single special shaped tool can be used. In general, present invention also intends to cover other easy changes for the technologist. 
     Embodiment 7 
     Equipment 
     Refer to  FIG. 8˜11 ; present invention provides an equipment for mounting a clip fastener with protrusion to gasket. The equipment includes a rack  100  and there are several rotatable noses  11  and one gasket apparatus which can move back and forth alternatively in relation to noses  11 . 
     It can be more clearly seen from  FIG. 9  that noses  11  is multidimeter and there is a flat narrow channel  12  locating the front of nose to place clip fastener. Two subassemblies are formed at the front end of noses  11  divided by narrow channel. One subassembly in relation to the other subassembly has protrusion in an axial direction. Clip fasteners are mounted to the narrow channel  12  of noses  11  with the protrusions blocked by the axial protrusion thus the end of clip fastener  209  is separated outwards from the plane of base  207 . Gasket apparatus moves the gasket closer to clip fastener and pricks the end  209  of clip fastener into gasket and then rotate the end  209  of clip fastener into gasket by noses  11 . 
     Referring to  FIG. 8  and  FIG. 10 , gasket apparatus and noses  11  are placed on the rack  100  abreast. Gasket apparatus includes groove  1  to place gasket. On right back plate  2  of groove  1 , there are side openings in horizontal array to pass the clip fastener into gasket. A row of little hole related to noses  11  is depicted in the figure. In groove  1  there is a squeezing block  3 . When gasket is placed into groove  1  and groove cover  4  is covered, squeezing block  3  will push the gasket to the right back plate  2  of groove  1 . At bottom of squeezing block  3  there is a drive rod  5  fixed vertically. Accordingly, there is a rail to stretch drive rod  5  outwards at bottom of groove. As squeezing block  3  moves, drive rod  5  will move along the rail. In base  6  below groove  1 , there is a spring  7 . One end of the spring  7  is fastened to the left lateral wall of base  6  and the other end is fastened below to drive rod  5 . Elastic force will impel drive rod  5  and squeezing block  3  to move towards right back plate  2  of groove  1 . At the bottom of drive rod  5  there is a connecting rod which pass through left lateral wall of base and then connected to the central section of the lever  9  outside base  6 . Base  6  is connected actively to the lower end of lever  9  and can rotate around the bottom subassembly. The upper end locates at the opening of groove cover  4 . Groove cover  4  and the left back plate of groove  1  are connected actively through hinge. As soon as groove cover  4  is opened and inverts to the left side, groove cover  4  will touch on the upper end of lever  9  to cause lever rotate around the lower end. In this way, connecting rod  8  will be draught, drive rod  5  slides to the left side and at the same time squeezing block  3  slides to the left side. Then it is time to replace gasket. After the gasket is replaced, close groove cover and no force is applied to the upper end of lever. Then drive rod  5  will slide to the right side and squeeze the gasket to the right back plate  2  in the action of elastic force. 
     There are blades fixed at one end of groove cover  4  and groove  1  each, and lower blade  33  in groove  1  can be seen in  FIG. 11 . When gasket is placed correctly and groove cover  4  is closed, groove cover and groove engage together to cut off gaskets in groove. 
     On the right side of gasket apparatus there are noses  11  for clip fastener mounting. When gasket apparatus move to noses  11 , the clip fastener over nose  11  will enter into gasket through the little hole of right back plate. Base of gasket apparatus is set on rail  10 . At the bottom of gasket apparatus, there are several drive arms connected to drive apparatus  32 , which can move gasket apparatus back and forth alternatively along rail  10 . Drive apparatus  32  can be air-actuated, hydraulic or electric-driven. Its impetus output rod is connected to drive arm. 
     First photosensor  30  is located on rack  100  of gasket apparatus where it is close to noses  11 . When gasket apparatus is ready and the end  209  of clip fastener is pricked into gasket, first photosensor  30  send out signal to rotate noses  11 . Clip fastener fastened on noses  11  also begins to rotate and separate the end  209  from the plane of the base  207  and rotate base  207  into the metal mesh in gasket. After base  207  is rotate into gasket, gasket apparatus will move back to initial position, drag clip fastener out from nose  11 , and then get gasket with clip fastener from the groove  1  of gasket apparatus. Second photosensor  31  is set on rack  100  near an initial position of gasket apparatus. When gasket apparatus comes back to the initial position, second photosensor  31  sends out a signal to reverse noses  11  back to the initial state. 
     All noses  11  are fixed on rail  17  by nose base  15 . Rotor  14  behind noses  11  is set in the bearing of corresponding nose base. A gear  16  is fixed behind rotor  14 . Head base  15  is fixed on rail  17  by screws. Loose screws to slide head base  15  along rail  17 , to adjust the distance between different bases  15  and sequentially adjust the distance of clip fasteners in gasket. 
     It can be seen in  FIG. 8  that main shaft  18  driven by motor is fixed behind noses  11  by bearing base  19 . Main shaft  18  is perpendicular to rotor of noses  11 . Number of gear fixed on main shaft  18  is same as that of noses  11 . These gears engage with gear  16  behind corresponding rotor of heads. When main shaft  18  rotates, each nose  11  is driven through gears. Initially, each narrow channel  12  of nose  11  is horizontally which makes it easy to mounting clip fastener on noses  11 . As first photosensor  30  sends out signal, the motor drive main shaft  18  and noses  11  to rotate the clip fastener into gasket. Then the gasket apparatus will return to initial position under the action of drive arm and clip fastener falls from noses  11 . After second photosensor  31  sends out signal, motor drive main shaft  18  to reverse noses  11  and thus narrow channel  12  returns to horizontal state. A revolving tray is fixed to main shaft  18 . When narrow channel of noses  11  is not horizontal, adjust revolving tray to rotate main shaft and keep narrow channel horizontal. 
     See  FIG. 10 , there is a grip block apparatus used to grip gasket ends at one end of gasket apparatus. In groove  1  of gasket apparatus, one end of grip block  20  is mounted to groove by a pin roll  21  and the grip block  20  can rotate around the pin roll  21 . Connecting rod  22  is fixed in the center part of grip block and passes through lateral wall of groove. One hand knob  23  is fixed at the outside end. A spring  24  is hitching between connecting rod  22  and groove  1 . 
     For the sake of automatic control, drive apparatus used to rotate noses  11  and move gasket apparatus move back and forth alternatively can be inserted into a control apparatus, together with first photosensor  31  and second photosensor  32  of gasket apparatus to implement automatic control. 
     The equipment in present invention also has many variations and modifications. The detailed structure is not limited to the embodiment mentioned above. For example, power supply and driving mode of all locomotive subassemblies can be different styles based on current technology; grip block used to grip the ends of gasket and the position or structure of blades used to cut gasket can also be different styles based on current technology. Control apparatus for automotive control can be singlechip or microcomputer etc. and can be located on integrated rack or individually set up. In general, present invention should also cover other easy variations or modifications for the technologist.