Switch knob with positioning arrangement

Abstract: In a lamp body (25) to which a switch knob (3) is attached, an opening (19) corresponding to the switch knob (3) is formed. Opening (19) has opposing sidewalls (20a, 20b), and on each of the sidewalls, three grooves (21a, 21b) are provided. On one surface of a knob body (27) of the switch knob (3), a pair of projecting pieces (31a, 31b) are provided spaced from each other by such a distance that allows the projecting pieces to be in contact with the sidewalls (20a, 20b) of the opening (19), and at each of the projecting pieces, a beam portion (33a, 33b) is formed. On each of the beam portions (33a, 33b), a projection (35a, 35b) is provided on the outer surface, and stable engagement with the vertical groove (21a, 21b) is realized.

Description: BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an apparatus for positioning a switch knob, and more specifically, to an apparatus for positioning a switch knob used for controlling on/off or the like of a battery feeded head lamp attached on a bicycle or the like. Description of the Background Art Fig. 7 is a side view showing a head lamp 1 employing a conventional positioning apparatus, attached on a handle 7 of a bicycle 43. Fig. 8 shows a specific structure of the head lamp 1 attached on a handle 7 of Fig. 7, Fig. 9 is a front view and Fig. 10 is a rear view thereof. Referring to these figures, an attachment part 2 consists of an upper member 9 and a lower member 11 which are rotatable around a pin 45. When attached to handle 7 of a bicycle, attachment screw 17 is removed, upper member 9 and lower member 11 are rotated about the pin 45 with their end portions expanded, and attachment part 2 is attached on the handle 7 of a bicycle with a rubber 47 wound around the handle 7. Thereafter, attachment screw 17 is fastened, so that a force gripping handle 7 is applied to the upper and lower members 9 and 11, and hence the attachment part 2 is firmly attached on handle 7 with rubber 47 interposed. On a lamp body 25 at a rear portion of head lamp 1, a switch knob 3 for controlling on/off of the lamp is provided, which is operated referring to an indication mark 5. An attachment part 13 is attached on a lower portion of head lamp 1 by means of an attachment screw or the like. At a rear portion of attachment part 13, a lever 15 used for attachment/detachment to and from the attachment part 2 is provided. Fig. 11 is a perspective view of switch knob 3 of Fig. 10 separated from lamp body 25 and a portion of the lamp body 25 viewed from the inside of the head lamp 1. Referring to the figure, there is a rectangular opening 19 in lamp body 25. Opening 19 has opposing sidewalls 60a and 60b, the sidewall 60a is provided with two vertical grooves 61a and the sidewall 60b is provided with two vertical grooves 61b, which grooves each has semi-circular cross section and extending in thickness direction of the plate of the lamp body 25. At the opening 19 on the side of the lamp body 25, a switch plate 49 having a bent portion, and a terminal plate 51 positioned above a tip end of switch plate 49 are provided. When a switch plate 49 is brought into contact with terminal plate 51, a drive battery contained in head lamp 1 is electrically connected to the lamp, and the lamp is turned on. Meanwhile, on the inner surface of a knob body 27 of switch knob 3, a pair of first projecting pieces 53a, 53b and a pair of second projecting pieces 57a and 57b are attached. The space between the first projecting piece 53a and the second projecting piece 57b, and the distance between the first projecting piece 53b and the second projecting piece 57a correspond to the space between opposing sidewalls 60a and 60b of the opening 19. On the outer surfaces of the first projecting pieces 53a and 53b, semi-spherical projections 55a (not shown) and 55b are provided respectively. Near the tip ends of the second projecting pieces 57a and 57b, guide portions 37a and 37b having a triangular cross section are formed in a direction parallel to the upper surface of the knob body 27. At a central portion of the knob body 27, a third projecting piece 59 facing toward the switch plate 49 is attached. Fig. 12 is a perspective view showing the switch knob 3 fitted in the opening 19, from the state of Fig. 11. Referring to the figure, guide portions 37a and 37b formed at the second projecting pieces 57a and 57b respectively are engaged with the inner surface of lamp body 25 at the edges of opening 19, and guide sliding operation of switch knob 3 in the direction of the arrow. Projections 55a and 55b formed at the first projecting pieces 53a and 53b, respectively, engage with one of the vertical grooves 61a and one of the vertical grooves 61b, respectively. In the figure, switch knob 3 is positioned corresponding to a power off state. When the switch knob 3 slides in the direction of the arrow from this state, each of the projections 55a and 55b move to and engage with vertical grooves which are next to the vertical grooves with which the projections have been engaged, and the position of the switch knob 3 is stabilized. As the switch knob 3 is moved, the third projecting piece 59 projecting from the central portion of knob body 27 to the direction of the switch plate 49 also moves in the direction of the arrow, pushes up the tip end of switch plate 49, so that the tip end is brought into contact with the terminal plate 51. Therefore, the power is turned on and light is emitted from the head lamp 1. In the conventional apparatus for positioning the switch knob as described above, it is difficult to have appropriate response of clicking when the knob is slid, since projections 55a and 55b engaging with vertical grooves 61a and 61b are attached on plate shaped projecting pieces 53a and 53b which pieces each have one end fixed on the knob body 27 and appropriate engaging force cannot be generated as the position of the projections must be on the side of the knob body 27. If the projections 55a and 55b are to be provided at tip ends of the first projecting pieces 53a and 53b, thickness of the first projecting pieces 53a and 53b must be increased. Further, since the first projecting pieces 53a and 53b have plate shape, they cannot be formed accurately by resin molding. Therefore, projections 55a and 55b cannot be fitted with high precision in the vertical grooves 61a and 61b, and the projections cannot apply appropriate pressing force. As a result, good response of clicking cannot be obtained by the positioning apparatus. From the document US-A-4 441 000 there is known an apparatus for positioning a switch knob for changing state of electrical connection by sliding a switch knob, comprising: a body on which said switch knob is attached, and having an opening corresponding to said switch knob (2a); at least two grooves (1b) formed at a portion of a sidewall of a frame located at the underside of the body and around said opening, in a direction of thickness of said body; a switch knob body which is a main portion of said switch knob. SUMMARY OF THE INVENTION The present invention was made to solve the above described problems, and its object is to provide an apparatus for positioning a switch knob which can surely provides appropriate click response. The above described object can be attained by the apparatus for positioning a switch knob in accordance with the present invention including a body, on which the switch knob is attached, having an opening corresponding to the switch knob; at least two grooves provided in the thickness direction of the body, at a portion of a sidewall of the opening; a switch knob body which is a main portion of the switch knob and having a shape appropriate for covering the opening; a pair of projecting pieces provided projecting from one surface of the switch knob body and spaced from each other by such a distance that allows the projecting pieces to be in contact with the sidewalls of the opening; a beam portion having opposing ends supported, formed in at least one of the pair of projecting pieces; and a projection formed at the beam portion and which can be fitted in one of the grooves. In the apparatus for positioning a switch knob structured as described above, a beam portion having opposing ends supported is provided on a pair of projecting pieces provided projecting from one surface of the switch knob body, and a projection formed at the beam portion engages with the groove, so that stable engagement between the groove and the projection is realized, and satisfactory response can be obtained when the switch knob is positioned. The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows how a head lamp incorporating the apparatus for positioning a switch knob in accordance with one embodiment of the present invention is attached. Fig. 2 is a perspective view of a switch knob 3 separated from a lamp body 25 and a portion of a lamp body 25 viewed from the inside of the head lamp 1 of Fig. 1. Fig. 3 is a cross section taken along the line III-III of Fig. 2. Fig. 4 is a cross section taken along the line IV-IV of Fig. 2. Fig. 5 shows a state when switch knob 3 is fitted in the opening 19 of lamp body 25, from the state of Fig. 2. Fig. 6 is a cross section taken along the line VI-VI of Fig. 5. Fig. 7 is a side view showing the head lamp employing the conventional positioning apparatus attached on a handle of a bicycle. Fig. 8 shows a specific structure of head lamp 1 attached to handle 7 of Fig. 7. Fig. 9 is a front view of the head lamp 1 in the state of Fig. 8. Fig. 10 is a rear view of the head lamp 1 in the state of Fig. 8. Fig. 11 is a perspective view showing a switch knob 3 of Fig. 10 separated from lamp body 25 and a portion of lamp body 25 viewed from the inside of head lamp 1. Fig. 12 is a perspective view showing the switch knob 3 fitted in opening 19 of lamp body 25, from the state of Fig. 11. DESCRIPTION OF THE PREFERRED EMBODIMENTS Fig. 1 is a rear view showing how a head lamp incorporating the apparatus for positioning a switch knob in accordance with one embodiment of the present invention is attached, which corresponds to Fig. 10 of the prior art. Referring to the figure, at a lamp body 25 at the rear portion of head lamp 1, there is provided a switch knob 3 for changing, in three steps, the state of electrical connection of the lamp, by sliding in lateral direction with reference to an indication mark 5. Other portions are similar to those of the prior art shown in Fig. 10. Therefore, description thereof is not repeated. Fig. 2 is a perspective view showing switch knob 3 of Fig. 1 separated from lamp body 25 and a portion of lamp body 25 viewed from the inside of head lamp 1. Fig. 3 is a cross section taken along the line III-III of Fig. 2, and Fig. 4 is a cross section taken along the line IV-IV of Fig. 2. Referring to the figures, as in the prior art, there is a rectangular opening 19 formed in lamp body 25. Opening 19 has opposing sidewalls 20a and 20b, and the sidewall 20a has three vertical grooves 21a at the central portion and sidewall 20b has three vertical grooves 21b at the central portion, which groove each have semi-circular cross section and extending in the thickness direction of the opening 19. At a central portion of opening 19, a switch coupling portion 23 connected to a terminal is positioned. On an outer surface of knob body 27 which is the main portion of switch knob 3, a knob piece 29 is provided, so as to facilitate sliding operation of switch knob 3. On the inner surface of knob body 27, a pair of first projecting pieces 31a and 31b are formed spaced from each other by such a distance that allows the projecting pieces to be in contact with the opposing sidewalls 20a and 20b of opening 19. In first projecting pieces 31a and 31b, elongate holes 32a, 32b and elongate holes 34a and 34b are provided parallel to each other and to the surface of the knob body 27, and by the provision of these holes, there are beam portions 33a and 33b formed with opposing ends supported. At an outer surface on the central portion of the beam portions 33a and 33b, projections 35a (not shown) and 35b having semi-circular cross section are formed. At the tip end portions of the first projecting pieces 31a and 31b, guide portions 37a and 37b having triangular cross sections are formed parallel to the upper surface of the knob body 27. In a space sandwiched by the first projecting pieces 31a and 31b, a pair of plate shaped second projecting pieces 39a and 39b are formed from the inner surface of knob body 27. On the outside of the second projecting pieces 39a and 39b, support members 41a and 41b are attached, so as to reinforce the second projecting pieces 39a and 39b against bending. The switch knob 3 including the first and second projecting pieces is formed integrally by resin molding. Fig. 5 is a perspective view showing the switch knob 3 fitted in the opening 19 of lamp body 25, from the state of Fig. 2, and Fig. 6 is a cross section taken along the line VI-VI of Fig. 5. Referring to the figure, guide portions 37a and 37b of the first projecting pieces 31a and 31b engage the inner surface of lamp body 25 at the edges of opening 19, and guides movement of switch knob 3 in the direction of the arrow. In this state, the projections 35a and 35b formed at the beam portions 33a and 33b of the first projecting pieces 31a and 31b respectively engage with any of the three vertical grooves 21a and any of the three vertical grooves 21b formed on the sidewalls of opening 19. In this example, the projections 35a and 35b are shown engaged with the central one of the three vertical grooves 21a and of 21b. Meanwhile, the pair of second projecting pieces 39a and 39b are positioned sandwiching a switch coupling portion 23. When the switch knob 3 is slid in the direction of the arrow while it is engaged with the opening 19 of lamp body 25, projections 35a and 35b move from any of the grooves of the vertical grooves 21a and 21b with which the projections have been engaged to adjacent other groove and engaged therewith. At this time, since projections 35a and 35b are provided at beam portions 33a and 33b which have opposing ends supported, the projections engage with the vertical grooves 21a and 21b with satisfactory resiliency. Therefore, appropriate response of clicking and stable movement and stopping of the switch knob 3 are ensured. As the switch knob 3 is slid in this manner, the switch coupling portion 23 also moves in the direction of the arrow, sandwiched by the pair of second projecting pieces 39a and 39b. Thus the position of the switch coupling portion 23 changes, electrical connection between the power supply and the lamp in the head lamp 1 changes, and thus on/off of the lamp can be controlled. Though there are three vertical grooves on each sidewall in the above described embodiment, the number of grooves may be two, four or more. Though the second projecting pieces 39a and 39b sandwich the switch coupling portion 23 in the above described embodiment, the switch plate 49 and the terminal plate 51 of the prior art may be used. Further, though projections 35a and 35b are engaged with the vertical grooves of opposing sidewalls of the opening 19 in the above described embodiments, the switch knob may be slid with the projection provided on only one of the projections and the grooves provided only one of the sidewalls. Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the scope of the present invention being limited only by the terms of the appended claims.

Claims: An apparatus for positioning a switch knob for changing state of electrical connection by sliding a switch knob (3), comprising: a body (25) on which said switch knob is attached, and having an opening (19) corresponding to said switch knob; at least two grooves (21a, 21b) formed at a portion of a sidewall (20a, 20b) of said opening, in a direction of thickness of said body; a switch knob body (27) which is a main portion of said switch knob and having a shape appropriate for covering said opening; a pair of projecting pieces (31a, 31b) provided projecting from one surface of said switch knob body, spaced from each other by such a distance that allows each of the projecting pieces to be in contact with the sidewalls (22a, 22b) of said opening; a beam portion (33a, 33b) having opposing ends supported, formed in at least one of said pair of projecting pieces; and a projection (35a, 35b) formed at said beam portion and engageable with one of said grooves (21a, 21b). The apparatus for positioning according to claim 1, wherein said at least two grooves are provided on each of opposing sidewalls of said opening; said beam portion is formed in each of said pair of projecting pieces; said projection is formed on each said beam portion; and each said projection is engaged with one of said at least two grooves provided on each of the opposing sidewalls of said opening. The apparatus for positioning according to claim 1 or 2, wherein said projecting piece has two elongate holes (32a, 32b, 34a and 34b) arranged parallel to each other, and said beam portion is formed at a portion sandwiched by said two elongate holes. The apparatus for positioning according to one of claims 1 to 3, wherein a guide portion (37a, 37b) to be engaged at an inner surface of said body (25) at an edge portion of said opening (19) is provided at a tip end of each of said pair of projecting pieces (31a, 31b). The apparatus for positioning according to one of claims 1 to 4, wherein said body is formed at a portion of a head lamp for a bicycle. The apparatus according to one of claims 1 to 5, wherein said opening has a rectangular shape.

Inventors: FUJIMOTO TAKUYA, FUJIMOTO, TAKUYA
Applicants: CATEYE CO LTD, CATEYE CO., LTD.
Application year: 1995
Main classification: H01H15
IPC codes: H01H15, H01H9, B60Q1