Abstract:
A dental flosser comprises a casing having a housing at one end for holding a supply of floss; a bent floss outlet section at the other end of housing forming an arc; an end hole in outlet section; a connecting rod disposed in casing between two ends; a slant body on front end of connecting rod; a flexible rod disposed in a channel in casing between ends thereof and having a slant groove connected with slant body of connecting rod; a switch connected to rear end of connecting rod including a protruding rod which is received in a hole in connecting rod; and a spring connected to casing and rear end of connecting rod. The tension of this flosser is adjustable and the flosser is free from external contamination.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a dental device and more particularly to a dental flosser in which the tension is adjustable and is free from external contamination. 
     BACKGROUND OF THE INVENTION: 
     FIG. 1 shows a prior art dental flosser made of plastics and shaped like a knife. A pair of parallel supports 1 and 2 extended downwardly are used for tightening a segment of floss 3. The top elongated member is used as a handle 4. Its structure is very simple and thus becoming a popular dental flosser set nowadays. However, it is inconvenient to user because of the following reasons: 
     1. It is disposable and the sharp end of plastic handle 4 may hurt the user and/or other people inadvertently. 
     2. In use, the dental flosser 3 between the supports 1 and 2 is susceptable to breakage when the gap between teeth is very narrow. 
     It is common that people do not bring a number of flossers while going out. Thus such use-and-throw away flosser is not ideal. As an end, people still do not like to bring flossers when going out despite extensive efforts made by dental hygienists. 
     SUMMARY OF THE PRESENT INVENTION 
     It is an object of the present invention to provide a dental flosser comprising a connecting rod for providing a floss with desired tension. 
     It is another object of the present invention to provide an improved dental flosser which receives most of the floss therein for preventing the floss from being stained by external contamination. 
     It is still another object of the present invention is to provide an improved dental flosser comprising a cutting unit which can readily cut off the used portion of the floss in order to keep the dental floss clean. 
    
    
     The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view showing a prior art dental flosser; 
     FIG. 2 is an exploded perspective view showing a preferred embodiment of the present invention; 
     FIG. 3 is a perspective view showing a partially assembled dental flosser of the present invention; and 
     FIGS. 4 and 5 are side views showing an assembled dental flosser of FIG. 2 and an opened switch respectively. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to FIGS. 2 and 3, the dental flosser of the present invention comprises a casing 10 and a clip-on cap 20 wherein the casing 10 of a generally E-shaped section consisting of a pair of symmetrical halves and an upper half portion 10a and a lower half portion 10b made of plastics. In the rear part of the upper half portion 10a there is a housing 101a. In the middle portion of the upper half portion 10a there is a sliding channel 102a. Under the sliding channel 102a and parallel to the sliding channel 102a is provided a dental floss groove 124. The sliding path 102a extends downward to form a channel 103a. The front of the upper half portion 10a is designed to bend downward like an arc. In hollowed middle part of the upper half portion 10a lies an arc floss groove 102c. An end arc portion corresponding to the lower half portion 10b forming a tiny hole 105 below the front of the casing 10. In the housing 101a of upper half portion 10a, a protruding pole 106a is provided. A spring 107 is inserted in to the hole of the protruding pole 106a wherein one end inserted in the hole of the protruding pole 106a and the other end is hooked in the rear end of a connecting rod 108. The rod 108 is positioned in the middle section of the sliding channel 102a of the casing 10. A hole 109 is provided on the rear end of the connecting rod 108. A protruding body 110 with a connecting hole 111 thereon is provided under the hole 109. The thickness of the rear portion of the connecting hole 111 is about one half of that of the front part of the connecting rod 108. On the front end of the connecting rod 108 a slant body 112 is formed. More specifically, the slant body 112 is a protruding strip slanted downward, The slant body 112 is assembled with astrip-shaped flexible rod 113 being fixed by the channel 103a of the upper half portion 10a. A slant groove 114 is provided on the upper part of the flexible rod 113 to connect with the slant body 112 of the connecting rod 108. A seam 115 is provided on the lower end of the flexible rod 113. After the upper half portion 10a and the lower half portion 10b have been attached together, an opening 116 is formed at the bottom thereof. A pair of guide rods 117 are provided on the upper wall and a pin 118 is provided on the lower wall of the casing 10. The pin 118 is used for mounting a switch 30. A lock point 120 is provided on the rear wall of the opening 116. On the lower part of the switch 30 a hole 31 is provided, while on its front part an elastic body 32 is formed. Above the elastic body 32 there is a protruded trigger 33 with a pin 34 on its top side for inserting into the connecting hole 111 on the lower part of the connecting rod 108. The thickness of the upper part of the trigger 33 is one half of that of its lower part. The rear part of the switch 30 is a platform 35. A latch 351 is provided on top of the platform 35. A protrusion 353 is provided on the rear end of the platform 35. A metal blade member 37 is put on the upper part of the platform 35. In front of the blade member 37 is a recess 371. The latch 351 of the switch 30 is inserted into the recess 371 for being secured therein. Above the blade frame 37 is a sharp blade 372 extended backward. Behind the blade 372 is a rectangular fixing groove 373. Beneath the platform 35 a locking point 352 protrudes. A groove 354 is provided at the end of platform 35. 
     A member 121 is provided on the inner surface of the upper half portion 10a. A rib 122a is provided in the inner wall of housing 101a. In front of the channel 103a of the upper half portion 10a there are a plurality of the engaging grooves 123. 
     The shape of the lower half portion 10b mates with that of the upper half portion 10a wherein a housing 101b is provided in the rear part, and a sliding channel 102b is provided in the middle portion. The sliding channel 102a bends downward to form a channel 103b. The front part of the channel 102a bends downward to form a semicircular concave arc on its bottom. Therefore, when the upper half portion 10a and the lower half portion 10b are attached together there is a tiny hole 105 formed at the tip. There are a plurality of fastening rods 106b spaced apart in the front part of the lower half portion 10b. An elastic rod 107b is provided in the rear housing 101b of the lower half portion 10b. Again, there is a floss-pressing rod 108b provided on the upper part of the inner wall of the lower half portion 10b. Meanwhile, a rib 122b is provided at a position in the lower half portion 10b corresponding to that of the rib 122a in the upper half portion 10a. Near the opening 116 of the lower half portion 10b there is a fixing rod 110b corresponding to the pin 118 in the upper half portion 10a. 
     The Cap 20 is a sleeve member corresponding to that of the front part of the upper half portion 10a. The cap 20 covers the front part of the casing 10 with a clamp 21 put on its outer surface. 
     A water-proof block 13 made of elastomeric material is provided adjacent an end of arc floss groove 102c. Waterproof block 13 has a raised portion 131 protrude into tiny hole 105 for preventing water from permeating into casing 10 for causing contamination. A rod member 14 is provided in the inner surface of lower half portion 10b. The rod member 14 urges against waterproof block 13 to keeping waterproof block 13 in place. One side of member 14 is slant, thereby enabling supply of floss 40 to pass therethrough. Then supply of floss 40 pass between waterproof block 13 and member 14 to the outside of casing 10 via the tiny hole 105. A waterproof peripheral flange 15 made of elastomeric material is secured on strip-shaped flexible rod 113. The flange 15 is located between seam 115 and strip-shaped flexible rod 113 abutted the walls of channels 103a, 103b for preventing water from permeating into casing 10. A similar flange is provided in switch 30 for preventing water from permeating into casing 10. 
     To assemble the apparatus, a spool is first put in between the clamps 12, i.e., between the upper and lower parts of the upper half portion 10a. Then the floss is pulled upwardly to pass through the central portion between guide poles 117. Then pass through the dental floss groove 124 beneath the sliding channel 102a in the front of the upper half portion 10a. The dental floss is further pulled to the arc floss groove 102c in the front of the upper half portion 10a. Then is pulled through the tiny hole 105 at the tip. Then the flexible rod 113 is put in the channel 103a of the upper half portion 10a. The connecting rod 108 is put on the sliding channel 102a in the upper half portion 10a. The slant body 112 of the connecting rod 108 is put in the slant groove 114 provided on the upper part of the flexible rod 114. The front end of spring 107 is inserted into the rear hole 109 of the connecting rod 108 and is hooked therein. The rear end of the spring 107 is inserted into the hole of protruding rod of the upper half portion 10a. The pin 118 of the upper half portion 10a is inserted into the hole 31 of the switch 30. The pin 34 of the trigger 33 of the switch 30 is inserted into the connecting hole 111 of the connecting rod 108. Finally, the lower half portion 10b is attached to the upper half portion 10a. At this time the fixing rod 110b of the lower half portion 10b is inserted in the hole 31 of the switch 30 in such a way that one half of the hole 31 is occupied by the fixing rod 110b and the other half is occupied by the pin 118 of the upper half portion 10a. The elastic rod 107b of the lower half portion 10b presses on the circular surface of the protruding rod 106a of the upper half portion 10a to cause the rear end of the elastic body 107 to be secured therein. The hole of the floss-pressing rod 108b of the lower half portion 10b is allowed to contain both the guide rods 117 of the upper half portion 10a. Hence the floss-pressing rod 108b is capable of pressing the supply of floss 40 to cause it to move forward horizontally, between guide rods 117 of the upper half portion 10a, along the dental floss groove 124. The joined part of the protruding body 110 of the connecting rod 108 and the trigger 33 of the switch 30 is clamped by the ribs 122a and 122b of the upper half portion 10a and lower half portion 10b respectively. The fastening rods 106b on the front of the lower half portion 10b just lies in the engaging grooves 123 on the front of upper half portion 10a. The flexible rod 113 is clamped by the channels 103a and 103b of the upper half portion 10a and the lower half portion 10b respectively. 
     After the upper half portion 10a and lower half portion 10b have been attached together, the supply of floss 40 is pulled out through the tiny hole 105 at the tip of arc formed by the downward extended front part of the upper half portion 10a. Then it moves forward and winds around the seam 115 below the flexible rod 113. In operation, if the bottom of the switch 30 and the bottoms of housings 101a and 101b lie in a transversal line as shown in FIG. 4. Then the dental flosser of the invention is ready for use for removing food particles from between the teeth. At this time, the end tip of the flexible rod 113 is drawn back to the casing 10 and is clamped by the surfaces of the channels 103a and 103b. Hence the supply of floss 40, which wound around the seam 115, is pushed upward by the flexible rod 113 and limited by the surfaces of channels 103a and 103b. As such, it wouldn&#39;t fall off. The end of the supply of floss 40 being pulled out lies between the flexible rod 113 and the wall surfaces of the housings 101a and 101b of the casing 10. Now the supply of floss 40 on top of the flexible rod 113 will be pushed up and clamped by the upper, left and right walls of the channel 103a of the casing 10a. The flexing rod 113 clamps the supply of floss 40 with both its upper end and lower end. As a result, the supply of floss 40 is ready for use. 
     In order to clean food particles from between the teeth with the supply of floss 40, first the locking point 352 of the switch 30 is pushed down and the platform 35 is pushed forward to cause the hole 31 to move backward. At this time the platform 35 lies flat. The groove 354 separates the lock point 120 from the wall of the opening 116 of the casing 10. Now the switch 30 is pushed downward to turn clockwise about pin 118 to an angle of about 15 to 22 degrees as shown in FIG. 5. The trigger 33 on the upper part of the switch 30 rotates clockwise simultaneously about 15-22 degrees to drive the pin 34 to rotate, while the pin 34 pushes the connecting rod 108 to move backward. As such, this push force combines with the tension of the spring 107 on top of the housing 101a will cause connecting rod 108 to move back significantly. As the slant body 112 on the front of the connecting rod 108 is inserted in the slant groove 114 of the flexible rod 113, once the connecting rod 108 moves backward, the slant body 112 will drive the flexible rod 113 to move downward. This is achieved by utilizing the relative motion of the upper and lower edges of the slant body 112 of the connecting rod 108. The slant groove 114 of the flexible rod 103 may produce a force to push the flexible rod 113 to move downward to make the seam 115, wound in the supply of floss 40, exposed at the opening on the bottom of the channels 103a and 103b of the casing 10. Then the dental floss is loosened and a used section is pulled out. The supply of floss 40 is passed through the guide pole 117, the dental floss groove 114, and the fine hole 105 at the tip of the casing 10, to the bottom edge of the opened blade 372. The used section of the supply of floss 40 is cut by blade 372 and a section of the clean supply of floss 40 is again wound on the seam 115 of the flexible rod 113. The switch 30 is pushed into the casing 10 again. At this time the groove 354 on the rear of the switch 30 is put under the lock point 120. The trigger 33 on the upper part of the platform 35 is moved to normal position. The connecting rod 108 is pushed by the pin 34 of the trigger 33 to return to its original position. The front slant body 112 of the connecting rod 108 is forced to drive the flexible rod 113 moving upward. Thus the supply of floss 40 wound on the seam 115 of the flexible rod 113 is drawn back into the channels 103a and 103b of the casing 10. The end of the supply of floss 40 clamped by the facings of the channels 103a and 103b is fixed so that it wouldn&#39;t fall off. Note that once the upper half portion 10a and the lower half portion 10b of the present invention are attached together, the fastening rods 106b will insert into the engaging grooves 123 of the upper half portion 10a for pressing on the supply of floss 40. As such, it will move along the bottom of the arc floss groove 102c. The pressing rod 107b in the rear housing 101b of the lower half portion 10b will press upon the protruding rod 106a of the upper half portion 10a. As such, the tip of the spring 107 presses in the hole of the protruding rod 106a to keep in place. The ribs 122a and 122b of the upper half portion 10a and the lower half portion 10b will clamp the joined portion of the connecting rod 108 and the trigger 33 of the switch 30. The pin 118 in the housings 101a and 101b of the lower half portion 10b and the fixer 110b are put in the hole 31 of the switch 30 on the left side and right side respectively to keep switch 30 in place. The casing 10 is covered with cap 20 on its front and is adapted to clamp on the pocket of user&#39;s clothes for achieving the purpose of convenient carry. 
     While the invention herein disclosed has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.