Patent Publication Number: US-6336732-B1

Title: Flashlight with a waterproof switching device

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a flashlight, more particularly to a flashlight having a waterproof switching device. 
     2. Description of the Related Art 
     Referring to FIGS. 1 and 2, a flashlight according to U.S. Pat. No. 4,940,860 is shown to include a barrel  1  and a waterproof switching device. As illustrated, the barrel  1  is formed with a radial switch opening  15 . The waterproof switching device includes a switch housing  10 , and a push-button switching element  12 . The switch housing  10  is formed with a radial button hole  13  that is aligned with the radial switch opening  15  and that has a large-diameter hole portion  130  proximate to the switch opening  15 , and a small-diameter hole portion  131  that is distal to the switch opening  15 , and an annular shoulder  14  that is defined between the large-diameter hole portion  130  and the small-diameter hole portion  131 , and that is located at one end of the button hole  13  which is distal to the switch opening  15 . The large-diameter hole portion  130  is confined by a hole-defining surface. The push-button switching element  12  is mounted in the switch housing  10 , and has a button-confining sleeve  120  and a button  121  movably confined by the button-confining sleeve  120 . The button-confining sleeve  120  and the button  121  extend through the small-diameter hole portion  131  and into the large-diameter hole portion  130  of the button hole  13 . The annular shoulder  14  cooperates with the hole-defining surface confining the large-diameter hole portion  130  of the button hole  13  to form an annular clearance. A resilient sealing member is disposed in the annular clearance, and has an operating portion  17  that projects into the switch opening  15  and that encloses the button  121  and the button-confining sleeve  120  therein, and an annular flange portion  18  that extends to the hole-defining surface confining the large-diameter hole portion  130  of the button hole  13  so as to establish watertight seal between the barrel  1  and the annular shoulder  14 . 
     Some of the disadvantages of the aforesaid conventional switching device are as follows: 
     During assembly of the switching device on the barrel  1 , the flange portion  18  of the sealing member must be inserted from an exterior of the barrel  1  into the annular clearance via the switching opening  15  so that the operating portion  17  is exposed from the barrel  1 . As such, a void may be formed among the flange portion  18 , the shoulder  14 , and an inner barrel surface  16  of the barrel  1 , thereby rendering the switching device non-waterproof. In addition, since no immobilizing device is applied between the inner barrel surface  16  of the barrel  1  and the switch housing  10 , replacement of battery may result in displacement of the switching housing  10  relative to the barrel  1 , which will affect the waterproofing effect of the switching device. 
     SUMMARY OF THE INVENTION 
     Therefore, the object of this invention is to provide a flashlight with a waterproof switching device which is clear of the disadvantages mentioned beforehand. 
     Accordingly, the flashlight of the present invention includes a barrel formed with a radial switch opening, and a waterproof switching device. The switching device includes a switch housing mounted in the barrel and formed with a radial button hole that is aligned with the radial switch opening and that has a large-diameter hole portion proximate to the switch opening, a small-diameter hole portion that is distal to the switch opening, and an annular shoulder that is defined between the large-diameter and small-diameter hole portions and that is formed at one end of the button hole which is distal to the switch opening. The large-diameter hole portion is confined by a hole-defining surface. A push-button switching element is mounted in the switch housing, and has a button-confining sleeve and a button movably confined by the button-confining sleeve. The button-confining sleeve and the button extend through the small-diameter hole portion and into the large-diameter hole portion of the button hole. The button-confining sleeve cooperates with the hole-defining surface confining the large-diameter hole portion of the button hole to form a first annular clearance. A resilient sealing member is disposed in the first annular clearance, and has an operating portion that projects into the switch opening, a tubular portion that extends from the operating portion and that encloses the button and the button-confining sleeve, and a peripheral flange portion that extends from one end of the tubular portion proximate to the shoulder and that extends to the hole-defining surface confining the large-diameter hole portion of the buttonhole. The tubular portion of the sealing member cooperates with the hole-defining surface confining the large-diameter hole portion of the button hole to form a second annular clearance. A retaining ring is fittingly disposed in the second annular clearance so as to urge the tubular portion of the sealing member to contact tightly the button-confining sleeve of the switching element, and so as to urge the peripheral flange portion of the sealing member toward the shoulder. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other features and advantages of this invention will become more apparent in the following detailed description of the preferred embodiment of this invention, with reference to the accompanying drawings, in which: 
     FIG. 1 is a fragmentary and partly exploded view of a flashlight disclosed in U.S. Pat. No. 4,940,860; 
     FIG. 2 is a fragmentary sectional view of the flashlight shown in FIG. 1; 
     FIG. 3 is a fragmentary, sectional view of the preferred embodiment of a flashlight according to the present invention; 
     FIG. 4 is an exploded view of a waterproof switching device employed in the preferred embodiment; 
     FIGS. 5 and 6 illustrate how the waterproof switching device is mounted on a barrel in order to form the preferred embodiment. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 3,  4 ,  5  and  6 , the preferred embodiment of a flashlight of this invention is shown to include an electrically conductive barrel  2 , and a switching device. 
     As illustrated, the barrel  2  is formed with a radial switch opening  21  (see FIG.  6 ). 
     The switching device includes a switch housing  3  mounted in the barrel  2  and formed with a radial button hole  301  that is aligned with the radial switch opening  21  and that has a large-diameter hole portion  302  proximate to the switch opening  21 , a small-diameter hole portion  303  that is distal to the switch opening  21 , and an annular shoulder  304  defined between the large and small-diameter hole portions  302 , 303 . Thus, the shoulder  304  is located at one end of the button hole  301  distal to the switch opening  21  in the barrel  2 . The large-diameter hole portion  302  of the button hole  301  is confined by a hole-defining surface. 
     A push-button switching element  5  is mounted in the switch housing  3 , and has a button-confining sleeve  501  and a button  51  movably confined by the button-confining sleeve  501 . The button-confining sleeve  501  and the button  51  extend through the small-diameter hole portion  303  and into the large-diameter hole portion  302  of the button hole  301 . The button-confining sleeve  501  cooperates with the hole-defining surface confining the large-diameter hole portion  302  of the button hole  301  to form a first annular clearance  305  (see FIG.  6 ). 
     A resilient sealing member  6  is disposed in the first annular clearance  305 , and has an operating portion  63  that projects into the switch opening  21 , a tubular portion  62  that extends from the operating portion  63  and that defines a cavity  620  to receive the button  51  and the button-confining sleeve  501  therein, and a peripheral flange portion  61  that extends from one end of the tubular portion  62  proximate to the shoulder  304  and that extends to the hole-defining surface confining the large-diameter hole portion  302  of the button hole  301 . The tubular portion  62  of the sealing member  6  cooperates with the hole-defining surface confining the large-diameter hole portion  302  of the button hole  301  to form a second annular clearance  306  (see FIG.  3 ). Preferably, the resilient sealing member  6  is made of an elastomeric material. 
     A retaining ring  7  includes an annular portion  72  fittingly disposed in the second annular clearance  306  around the tubular portion  62  of the sealing member  6  so as to urge the tubular portion  62  to contact tightly the button-confining sleeve  501  of the switching element  5 , and so as to urge the peripheral flange portion  61  of the sealing member  6  toward the shoulder  304 . The annular portion  72  of the retaining ring  7  defines a through hole  70  to permit extension of the operating portion  63  outwardly of the switch opening  21 . The retaining ring  7  can be made of a hard material, such as plastics or metal. 
     The waterproof switching device further includes a nut fastener  90  disposed in the large-diameter hole portion  302  of the button hole  301  between the peripheral flange portion  61  of the sealing member  6  and the shoulder  304 . The fastener  90  engages threadedly an externally threaded portion of the button-confining sleeve  501  such that the retaining ring  7  urges the peripheral flange portion  61  of the sealing member  6  to contact tightly the nut fastener  90 . 
     In this embodiment, the switch opening  21  has a large-diameter opening portion  210  proximate to an outer barrel surface of the barrel  2 , a small-diameter opening portion  211  proximate to an inner barrel surface of the barrel  2 , and a first annular flange  22  defined between the large and small-diameter opening portions  210 , 211  adjacent to the inner barrel surface. The large-diameter opening portion  210  is confined by an opening-defining surface. The annular portion  72  of the retaining ring  7  extends through the small-diameter opening portion  211  and into the large-diameter opening portion  210  of the switch opening  21 . The retaining ring  7  has a second annular flange  73  that extends radially and outwardly from an upper end  71  thereof and into the opening-defining surface confining the large-diameter opening portion  210  in such a manner that the first and second annular flanges  22 , 73  cooperatively form an annular groove therebetween. A rubber sealing ring  8  is disposed in the annular groove around the retaining ring  7  to establish a watertight seal between the barrel  2  and the retaining ring  7 . 
     Preferably, the switch housing  3  includes a first housing portion  30  defining the button hole  301  therethrough, and a second housing portion  31  that cooperates with the first housing portion  30  to form an accommodation chamber  308  (see FIG. 3) therebetween in communication with the button hole  301 . The switching element  5  further includes a switching seat  50  disposed in the chamber  308 . The button-confining sleeve  501  is mounted securely on the switching seat  50 . Two conductive terminals  500  have two inner ends embedded in the switching seat  50  proximate to the button  51 , and two outer ends that extend outwardly from the switching seat  50 . The first housing portion  30  is further formed with a threaded hole  300  in communication with the chamber  308 . A bulb assembly  4  includes a bulb mounting tube  42  that has a first portion  420  threadedly mounted to the hole  300  in the first housing portion  30 , and a second portion  421  within which a bulb (L) is mounted. A conductive spring retainer  41  is disposed in the first portion  420  of the tube  42  and in contact with the bulb (L). A spring  40  is disposed in the spring retainer  41 , and extends through the hole  300  in the first housing portion  30  to connect electrically with one of the outer ends of the conductive terminals  500 . The other one of the outer ends of the conductive terminals  500  is exposed outwardly from the chamber  308  and is adapted to contact a battery unit (not shown) when the latter is disposed in the barrel  2 . The button  5  is operable to permit electrical connection between the inner ends of the conductive terminals  500  so as to light the bulb (L). 
     Note that during assembly of the flashlight of the present invention, the switch housing  3  is inserted into the barrel  2  from a rear opening thereof, while the bulb mounting tube  42  of the bulb assembly  4  is inserted from a front opening thereof and is threaded to the first housing portion  30 . After mounting of the nut fastener  90  and the retaining ring  7  in the button hole  301  of the switch housing  3 , the switch housing  3  is prevented from axial displacement relative to the barrel  2  so as to immobilize the housing  3  in the barrel  2 . In addition, the sealing ring  8  employed in the switch device of the flashlight of the present invention provides an enhanced waterproofing effect. 
     With this invention thus explained, it is apparent that numerous modifications and variations can be made without departing from the scope and spirit of this invention. It is therefore intended that this invention be limited only as indicated in the appended claims.