Abstract:
Swimming goggles include a frame body, lenses, buckles attached to left and right portions of the frame body, and a head strap passed through the buckles. Each of the buckles has a base having a connecting portion and a guiding portion, and an operating portion. With the head strap being frictional engaged with the guiding portions and retained by the operating portion and being stretched after wearing of the swimming goggles, the head strap is adjustable through the buckles without taking off the swimming goggles, so as to provide a quick and easy adjustment, and a lower cost of manufacturing because of simplified structure.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to swimming goggles, and particularly to swimming goggles which have easily-adjustable buckles for tightening and loosening a head strap without taking off the swimming goggles. 
     2. Related Art 
     Generally, it is necessary to adjust a head strap when wearing swimming goggles. As is well known, the length of a head strap is being adjusted with buckles of frames of swimming goggles. Early buckles are only intended to allow the head strap to pass through. Once the head strap is to be adjusted, it has to be taken off from a wearer first, and then is manually moved backwards and forwards through the buckles in a direction of where it is passed through. Due to the inconvenient adjustment of the head strap, late buckles of swimming goggles are improved to have an engaging structure. The engaging structure has an engaging arm for being engaged with saw-shaped slots of a head strap so as to retain the head strap in place, whereby the head strap is only allowed to be tightened in one direction, without taking off the swimming goggles. To loosen the head strap, the engaging arm is to be disengaged with the saw-shaped slots. As a result, adjustment of the head strap of traditional swimming goggles depends entirely on the engagement and disengagement of the engaging arm and the saw-shaped slots. 
     Although the head strap of the above-mentioned traditional swimming goggles is adjustable without being taken off, the traditional buckles and head strap are still cumbersome and large in size, and therefore cause a higher cost of manufacturing. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of the present invention is to provide swimming goggles having buckles which are easily and detachably to be assembled, and enable a quick adjustment of a head strap without taking off the swimming goggles, and have simple structures so as to further lower the manufacturing cost. 
     To achieve the above-mentioned object, swimming goggles of the present invention comprise a frame body, lenses, buckles attached to left and right portions of the frame body, and a head strap passed through the buckles; wherein each of the buckles comprises a base having outer and inner surfaces, a connecting portion, and a guiding portion, the connecting portion connected with the left and right portions of the frame body, the guiding portion forming an opening therein and being provided with a rib dividing the opening into a first guiding hole adjacent to the connecting portion, and a second guiding hole adjacent to the operating portion; and an operating portion provided with a pressing lip formed adjacent to the second guiding hole, the pressing lip extending towards the inner surface of the base and beyond an outer surface of the rib; and wherein the head strap passes through the first guiding hole from the inner surface of the base and around the rib to pass through the second hole and the inner surface again. 
     With the above-mentioned structure, once the swimming goggles of the present invention is being put on, sides of the strap with respect to the first guiding hole are being pulled and stretched outwards to be attached to the free end portions of the strap with respect to the second guiding hole, wherein the free end portions are frictionally engaged with the pressing lips, and portions of the strap adjacent to the first guiding hole are frictionally engaged with the ribs. Accordingly, the head strap is firmly retained by the frictional engagement with the ribs and the pressing lips, and is therefore not moveable. When the strap is needed to be loosened, just pull the operating portions outwards towards the outer surfaces to release the free end portions engaged by the pressing lips and to lower friction between the strap and the ribs, so as to allow the strap to move automatically within the first and second guiding holes, without being taken off from a wearer. When the strap is to be tightened, just pull the free end portions backwards to a desired length, without being taken off from the wearer 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view of swimming goggles of the present invention. 
         FIG. 2  is a perspective assembly view of  FIG. 1 . 
         FIG. 3  is a schematic top plan view of the swimming goggles. 
         FIG. 4  is a cross-sectional view taken along the line  4 - 4  in  FIG. 3 . 
         FIG. 5  is a schematic cutaway side view showing a buckle of the swimming goggles. 
         FIG. 6  is a schematic view showing a head strap is being fastened with the buckles of the present invention. 
         FIG. 7  is a schematic view showing the buckles are being pushed outwards to release the heat strap. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIGS. 1 and 2 , swimming goggles  1  of the present invention comprises: a frame body  2 , lenses  30 ,  31 , buckles  4  attached to left and right portions of the frame body  2 , and a head strap  5  passed through the buckles  4 . The frame body  2  comprises left and right frames  20 ,  21 , a nose bridge  22  interconnecting the left and right frames  20 ,  21 , and protective portions  231 ,  232  attached on the left and right frames  20 ,  21 , respectively. The lenses  30 ,  31  and the left and right frames  20 ,  21  are integrally formed and made of Polycarbonate resin (PC), and the left and right frames  20 ,  21  are formed with lip edges  201 ,  211 . The lip edges  201 ,  211  are recessed from peripheral portions of the left and right frames  20 ,  21  opposite to the lenses  30 ,  31  and are intended to facilitate the formation with the protective portions  231 ,  232 , whereby to allow the peripheral portions of the protective portions  231 ,  232  to cover and be attached firmly on the lip edges  201 ,  211 . The protective portions  231 ,  232  are made of thermal plastic rubber (TPR) for protecting a contact area of a wearer&#39;s face and providing a comfortable contact when wearing. 
     The buckles  4  are made of thermoplastic polyurethane (TPU), each buckle  4  comprising a base  40  having outer and inner surfaces  401 ,  402 , and an operating portion  43 , wherein the base  40  further has a connecting portion  41  and a guiding portion  42 . The connecting portion  41  slightly bends inwards and towards the lenses  30 ,  31  and has a substantially board shape. The connecting portion  41  forms a connecting hole  410  thereon. The left and right frames  20 ,  21  are provided with hook portions  202 ,  212  which bend inwards and towards the lenses  30 ,  31 , respectively. The connecting portions  41  are detachably hooked in the hook portion  202 ,  212  with the connecting holes  410  so as to connect the bases  40  with the left and right frames  20 ,  21 . The guiding portion  42  forms an opening  421  therein and is provided with a rib  422  which divides the opening  421  into a first guiding hole  423  adjacent to the connecting portion  41 , and a second guiding hole  424  adjacent to the operating portion  43 . The rib  422  has an oval section (as shown in  FIG. 5 ), and a lengthwise axis of the oval second is tilted with respect to the inner surface  402  of the base  40  at an angle of 45 degrees. With the structure of the rib  422 , the strap  5  passes through the first guiding hole  423  from the inner surface  402  of the base  40 , and then pass around the rib  422  at 45 degrees through the second hole  424  and the inner surface  402  again. Each operating portion  43  is provided with a pressing lip  431  formed on an inner wall of the operating portion  43  with respect to the inner surface  402  of the base  40  and adjacent to the second guiding hole  424 . The pressing lip  431  protrudes outward from the inner wall of the operating portion  43  and beyond an outer surface of the rib  422  such that the operating portion  43  increases in thickness. 
     Particularly, a maximum width of the guiding portion  42  is larger than that of the operating portion  43 , the maximum width of the operating portion  43  is larger than that of the connecting portion  41 . Because the connecting portion  41  is thinner than the guiding portion  43  and the operating portion  43 , and has the substantially board shape, the operating portion  43  is therefore movable with the connecting portion  41  functioned as an axis. 
     The head strap  5  is made of silicone and has two opposite free end portions  501 ,  502 . Two protruding portions  50  are formed on a side of the head strap  5  and adjacent to the free end portions  501 ,  502 , respectively (as shown in  FIG. 2 ), for preventing the head strap  5  from being pulled out of the second guiding holes  424 . 
     Referring to  FIG. 1  in combination with  FIGS. 2 to 4 , prior to assembly of the swimming goggles  1 , the left and right frames  20 ,  21  and the lenses  30 ,  31  are integrally formed with the protective portions  231 ,  232 . As a result, the nose bridge  22  is only needed to be assembled with the left and right frames  20 ,  21 . And the buckles  4  are detachably hooked in the hook portion  202 ,  212  with the connecting hole  410  so as to connect the bases  40  and the left and right frames  20 ,  21 . The buckles  4  are easily and quickly removable from the hook portion  202 ,  212  for the purpose of repair, replace, or storage in a container. 
     Referring to  FIGS. 5 and 6 , once the swimming goggles  1  of the present invention is being put on, sides of the strap  5  with respect to the first guiding hole  423  are being pulled and stretched outwards to be attached to the free end portions  501 ,  502  of the strap  5  with respect to the second guiding hole  424 , wherein the free end portions  501 ,  502  are frictionally engaged with the pressing lips  431 , and portions of the strap  5  adjacent to the first guiding hole  423  are frictionally engaged with the ribs  422 , and wherein each of the respective free end portions  501 ,  502  passing through the respective first and second guiding holes  423 ,  424  bends back onto the head strap  5  at the respective pressing lip  431  as a bending point of which a bending angle is changeable by moving the respective operating portion  43  in a direction from the inner surface  402  to the outer surface  401  of the respective base  40  so as to reduce a friction force arisen from the respective bending point and allow adjustment of the head strap  5 , and wherein the respective free end portion  501 ,  502  is frictionally sandwiched between the head strap  5  and the respective operating portion  43  at the respective bending point when the respective operating portion  43  is not being moved in the direction from the inner surface  402  to the outer surface  401  of the respective base  40 . Accordingly, the head strap  5  is firmly retained by the frictional engagement with the ribs  422  and the pressing lips  431 , and is therefore not moveable (as shown in  FIG. 5 ). When the strap  5  is needed to be loosened, just pull the operating portions  43  outwards towards the outer surfaces  401  (as an arrow direction shown in  FIG. 5 ) to release the free end portions  501 ,  502  engaged by the pressing lips  431  and to lower friction between the strap  5  and the ribs  422 , so as to allow the strap  5  to move automatically within the first and second guiding holes  423 ,  424  (as shown in  FIG. 7 ), without being taken off from the wearer. When the strap  5  is to be tightened, just pull the free end portions  501 ,  502  backwards to a desired length, without being taken off from the wearer. 
     It is understood that the invention may be embodied in other forms within the scope of the claims. Thus the present examples and embodiments are to be considered in all respects as illustrative, and not restrictive, of the invention defined by the claims.