Bulb holding structure

Abstract: A bulb holding structure according to the invention includes a pair of spring fixing members 11 and a projection 12 having a spring holding claw 14. The spring fixing members 11 and the projection 12 are disposed on the back side of a reflector 1 and located opposite to each other with respect to a bulb 8 inserted in a hole of the reflector 1. A spring catching concavity 13 is made in the outer face 12b of the projection 12. The outer face 12 is exposed in a direction opposite to the members 11. The spring catching concavity 13 is formed U-shaped by a pair of side grooves 13a, 13b elongated in a direction in which a push portion 10c of a spring 10 is pressed and a groove 13c linking the side grooves 13a, 13b with each other. The other ends of the side grooves 13a, 13b are open toward the push portion 10c. The claw 14 is given in the concavity 13 by excavating the projection 12 as mentioned above. The projection 12 is further provided with an inclined guide face 14b for catching the spring 10 and an inclined guide face 15 for releasing the spring from the claw 14. The releasing guide face 15 is inclined so that a portion 10b' of the spring 10 to be held by the claw 14 is disengaged from the claw 14 and guided along the guide face 15 by pressing the push portion 10c. The catching guide face 14b is inclined in the same direction as the releasing guide face 15.

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a reflector assembly in which a bulb is fixed in a reflector by means of a formed wire as indicated in the preamble portion of claim 1. A prior art bulb holding structure is known as shown in Figs. 5 to 7 (see Japanese Utility Model Publication Hei 1-164612). It is also disclosed in French Patent Application Nos. 2630193 and 2669400. Referring to Fig. 5, a reflector assembly 1 includes a reflector 2 and a bulb holder set 3. The bulb holder set 3 includes a bulb holder 4 and a formed wire (spring) 5 for holding a bulb. The bulb holder 4 includes a flange 4a extended radially and edge portions 4b, 4c jutting out from the flange 4a. The edge portions 4b, 4c integrated with the flange 4a are fastened to the back side 2a of the reflector 2 by means of machine screws 6, 6. Ribs 4d, 4d are formed around the flange 4a. One of the ribs 4d, 4d is provided with a hook 4e elongated to the middle of the edge portion 4c. On the edge portion 4b is disposed a wire fixing member 4f to which the wire 5 is turnably fixed. A free end 5a of the wire 5 is caught and held by the hook 4e. Further, the bulb holder 4 is provided with an internal flange 7 jutting out to the center of the bulb holder 4 inside the reflector 2. A bulb 8 is inserted in a hole 7a formed inside the internal flange 7. The bulb 8 includes a lighting portion 8a, a base 8b to which the lighting portion 8a is fastened, and a flange 8c disposed on the base 8b. The flange 8c is fixed between the internal flange 7 and the formed wire 5. In the above-mentioned arrangement, the free end 5a of the formed wire 5 is disengaged from the hook 4e by moving the free end 5a in a direction of the arrow A as shown in Fig. 7. On the other hand, the free end 5a is engaged with the hook 4e by moving the free end 5a in a direction of the arrow B. However, such engagement or disengagement is not easily carried out because an operator's hand must be moved in a narrow space in which the free end 5a and the hook 4e are contained while an operator observes them. Further, there is a problem in that the formed wire 5 is unstably placed in such a manner that the middle portion of the formed wire 5 is fixed to the member 4f and the free end 5a is engaged with the hook 4e by means of only the elasticity of the formed wire 5. A solution to the problems is disclosed in French Patent Application No. 2626062 for a holding structure as shown in Fig. 8. Referring to Fig. 8, an annular convexity 21 is disposed on the back surface of a reflector 20 through which a hole 22 is cut. A pair of spring fixing projections 23, 23 adjacent to each other are formed on the annular convexity 21. A spring catching projection 24 opposite to the projections 23, 23 is also formed thereon. In the catching projection 24 are formed an inclined face 25 for catching a spring, a hollow 26 for holding the spring, and an inclined face 27 extended from the hollow 26 for releasing the spring. A short length portion of a rectangular spring 28 is turnably fixed to the projections 23, 23. The long length portions 28b, 28b of the rectangular spring 28 is bent at its middle points 28c, 28c. The free end portion of the spring 28 is further provided with portions 28e, 28e bent in the same direction as the long length portions 28b, 28b with respect to points 28d, 28d. The end linking the portions 28e, 28e, i.e., the other short length portion of the rectangular spring 28 serves as a portion 28f to be caught by the projection 24. As shown in Fig. 9(a), a cylindrical object 29 is inserted into the hole 22 so that a flange 29a of the object 29 is brought into contact with the annular convexity 21. After that, the short length portion 28f is brought into contact with the inclined guide face 25 and, at the same time, the middle points 28c, 28c are brought into contact with the bottom 29b of the cylindrical object 29 as shown in Fig. 9(b). Then, the points 28d, 28d are pressed with force F toward the guide face 25, so that the short length portion 28f is guided along the face 25 and held in the hollow 26 as shown in Fig. 9(c). By pressing the points 28d, 28d still more in the direction of the arrow F as shown in Fig. 9(d) when the short length portion 28f is held in the hollow 26, the short length portion 28f is disengaged from the hollow 26 and guided along the face 27 as shown in Fig. 9(e) and then released therefrom as shown in Fig. 9(f). In this structure, the cylindrical object 29 is stably placed because the long length portions 28b, 28b are firmly pressing the bottom 29b of the object 29. However, because the releasing guide face 27 is inclined in the opposite direction to the catching guide face 25 and the tip of the guide face 27 is located higher as shown in Fig. 9, the points 28d, 28d must be pressed with great force in order to bend the spring 28 less than an angle  shown in Fig. 9(c) and release the short length portion 28f from the hollow 26. Furthermore, said document FR-A-2 626 062 discloses an alternative spring holding projection which isU-shaped formed by means of three side walls. Said spring holding projection opens similarly to that of figure 8 in a direction towards a spring fixing portion. Thus, the spring holding projection opens at a top area, at an inner area directed towards said spring fixing portion and is widely opened at the side walls extending in parallel to the curved portion of the spring due to an inclined guide means formed in said spring holding projection. Moreover, a claw is provided connected perpendicular to the side wall opposite said spring fixing portion, wherein said claw is contoured to open in a direction toward said spring fixing portion. SUMMARY OF THE INVENTION It is therefore an object of the invention to provide a reflector assembly having a bulb holding structure as indicated in the preamble portion of claim 1 in which, regardless of a narrow space limiting a satisfying movement of an operator's hand, an free end of a formed wire is easily caught by and released from a holding portion disposed on the back side of a reflector with slight force and without observing the free end, and in which the formed wire is stably placed in the reflector. This object is achieved by a reflector assembly comprising the features of claim 1. According to a prefered embodiment, the tip of the claw is located below the outer face of the projection when a lighting portion of said bulb defines a top area. Preferably, the U-shaped concavity is enclosed by walls contiguous to the side grooves and opposite to each other with respect to the claw and by a wall linking the side walls to each other; the releasing guide means includes first and second inclined guide faces, the first inclined guide face being formed so that the linking wall is inclined from the base of the claw to the outer face of the projection and in an opposite direction to the claw, the second inclined guide face being formed so that a part of either of the side walls is inclined from a place facing a spring holding portion of the claw to the outer face and in a direction approaching the other side wall; the U-shaped portion of the spring is disengaged from the spring holding portion of the claw and is guided along the first and second guide faces by pressing the U-shaped push portion of the spring against the elasticity of the spring. According to an advantagous embodiment of the reflector assembly, a third inclined guide face is formed so that a part of the other side wall is inclined from the bottom of the spring holding concavity to the outer face of the projection in a direction opposite to the second guide face. According to a further prefered embodiment the spring is made up of an erected portion bent in the opposite direction to the curved portion, and a folded portion turned up from the tip of the erected portion to a point corresponding to the root of the erected portion, the U-shaped portion of the spring being contiguous to the folded portion, the push portion being formed at a joint between the erected and folded portions. Preferably, the projection juts out in a direction perpendicular to the flange of the bulb; the erected and folded portions are elongated in a direction in which the projection juts out when the U-shaped portion of the spring is brought into contact with the spring catching guide face and when the U-shaped portion is held by the spring holding portion of the claw; the push portion is pressed in a direction perpendicular to the flange of the bulb in order to engage the U-shaped portion with the claw or disengage it from the spring holding portion. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1(a) is a sectional view of a bulb holding structure according to the invention and Fig. 1(b) is a front view of a spring holding portion of Fig. 1(a). Fig. 2 is a sectional view showing a spring released from the spring holding portion. Fig. 3 is a top view of Fig. (2). Figs. 4(a)-(c), (a')-(c') show the action of the bulb holding structure shown in Figs. 1 to 3. Fig. 5 is a sectional view of a conventional bulb holding structure. Fig. 6 is a bottom view of Fig. 5. Fig. 7 is an enlarged view of a hook of Fig. 6. Fig. 8 is a perspective view of another conventional bulb holding structure. Figs. 9(a)-(f) show the action of the bulb holding structure of Fig. 8. DETAILED DESCRIPTION OF THE EMBODIMENT A description of the embodiment of the present invention will be hereinafter given with reference to Figs. 1 to 4. Referring to Figs. 1 to 3, a reflector assembly 1 includes a reflector 2 and a bulb holder set 3. The bulb holder set 3 includes a cylindrical holder 4 disposed in the reflector 2 and a spring (formed wire) 10 for holding a bulb. On the bottom face of the holder 4 are formed a flange 4a extended radially and edge portions 4b, 4c jutting out from the flange 4a and integrated with the flange 4a. The edge portions 4b, 4c are fixed to the back face 2a of the reflector 2 by means of machine screws 6, 6. On the upper face of the holder 4 (exposed in the same direction as the reflecting surface of the reflector 2) is formed an internal flange 7 extended toward the center of the holder 4. A bulb inserting hole 7a is made inside the internal flange 7. A bulb 8 is held by the bulb holder set 3. The bulb 8 includes a lighting portion 8a to be inserted into the hole 7a, having a filament, a base 8b by which the lighting portion 8a is supported, and a flange 8c integrated with the base 8b and brought into contact with the holder flange 4a. As shown in Fig. 3, the spring (formed wire) 10 has right and left linear portions D, D and a portion C linking the free ends of the linear portions with each other so that it is formed into a U-shape as a plane view. The spring 10 further has portions 10a, 10a to be fixed to the holder 4 at the base side of the spring 10, each on the same axial line, a U-shaped portion 10b to be held by the holder 4 at the free end side of the spring 10, a push portion 10c, an erected portion 10d, a folded portion 10e, and a curved portion 10f formed at the middle of the spring 10 to be brought into contact with the flange 7. The erected portion 10d is formed in such a manner that a part of the linear portion D is rectangularly bent in the opposite direction to the curved portion 10f. The folded portion 10e is folded from the tip of the erected portion 10d so as to have the roughly same length as the erected portion 10d. A linking portion between the erected and folded portions 10d, 10e serves as the push portion 10c. The U-shaped portion 10b to be held by the holder 4 is contiguous to the folded portion 10e. Between the flange 4a and the edge portion 4b are disposed members 11, 11 for fixing the respective base ends 10a, 10a of the spring 10. Between the flange 4a and the edge portion 4c is formed a projection 12 jutting out in a direction perpendicular to the flange 4a. The pair of members 11, 11 and the projection 12 are located opposite to each other with respect to the hole 7a. The base ends 10a, 10a of the spring 10 are turnably fixed in the members 11, 11. The projection 12 is further provided with a projection 12a jutting out toward the edge portion 4c. In the projection 12a is formed a nearly U-shaped concavity 13 for catching and holding the spring 10. The U-shaped concavity 13 as a part of the back of the reflector 1 is open toward the edge portion 4c and the push portion 10c. A spring holding claw 14 integrated with the holder 4 is formed in the concavity 13. The summit of the claw 14 is located below (inner in the drawings) the outer face 12b of the projection 12. The spring catching concavity 13 is composed of a pair of side grooves 13a, 13b made in the outer face 12b (perpendicular to the flange 4a) of the projection 12 and a groove 13c linking the side grooves 13a, 13b with each other. The outer face 12 is exposed in a direction opposite to the members 11, 11. The side grooves 13a, 13b are elongated in a direction in which the push portion 10c of the spring 10 is pressed or in a direction parallel to the optical axis of the bulb 8. The other ends of the side grooves 13a, 13b are open toward the push portion 10c. The concavity 13 is surrounded by walls 13d, 13e of the side grooves 13a, 13b opposite to each other with respect to the claw 14 and a wall 13f (an inclined guide face 15 for releasing the spring 10, which will be described below) linking the walls 13d, 13e with each other. In the claw 14 are formed a portion 14a located on the side of the reflector 2 for holding the U-shaped portion 10b and an inclined guide face 14b located on the opposite side to the spring holding portion 14a for catching and guiding the U-shaped portion 10b. The linkage part 10b' of the U-shaped portion 10b of the spring 10 is engaged with the spring holding portion 14a and held thereby. The flange 8c of the bulb 8 is sandwiched between the flange 4a of the holder 4 and the curved portion 10f of the spring 10 and firmly placed in the reflector when the linkage part 10b' is held by the claw 14. On the lower side of the concavity 13 is formed a means for guiding and releasing the linkage part 10b' from the claw 14. The releasing means includes first, second, and third inclined guide faces 15 to 17. The first inclined guide face 15 is formed on the bottom side of the concavity 13 or on the wall 13f, the second inclined guide face 16 is formed on a part of the wall 13d corresponding the linking groove 13c, and the third inclined guide wall 17 is formed on a part of the wall 13e corresponding to the linking groove 13c. The first inclined guide face 15 is inclined from the bottom of the spring holding portion 14a in a direction in which the linkage part 10b' goes away from the claw 14. The first inclined guide face 15 is extended longer than the inclined guide face 14b and is inclined in the same direction as the guide face 14b. The second inclined guide face 16 is inclined from a point of the wall 13d in a direction in which the U-shaped portion 10b approaches the wall 13e. The third inclined guide face 17 is inclined from the bottom of the concavity 13 in a direction in which the U-shaped portion 10b goes away from the wall 13d. A description will now be given of the action of the bulb holding structure arranged as mentioned above. The bulb 8 is first inserted into the hole 7a of the inner flange 7, and then the free end portion of the spring 10 is turned to the reflector 2. The linkage part 10b' of the U-shaped portion 10b of the spring 10 is brought into contact with the inclined guide face 14b of the claw 14 so that the erected and folded portions 10d, 10e of the spring 10 are directed in a direction where the projection 12 juts out or in a direction perpendicular to the flange 4a. In this condition, the push portion 10c is pressed against the elasticity of the spring 10. The linkage part 10b' of the spring 10 is guided along the guide face 14b to be engaged with the claw 14 and is held by the holding portion 14a. As a result, the bulb 10 is firmly placed between the flange 4a and the spring 10. As shown in Fig. 1(a), the linkage part 10b' is caught by the holding portion 14a and the erected and folded portions 10d, 10e of the spring 10 are directed in the direction perpendicular to the flange 4a. To release the linkage part 10b' from the claw 14, the push portion 10c is pressed toward the guide faces 15, 16 against the elasticity F of the spring 10 with the force P1 of a finger 18 as shown in Figs. 4(a), 4(a'). The linkage part 10b' is released from the holding portion 14a and is guided along the guide faces 15, 16, 17 to the outer front face 12b of the projection 12 as shown in Figs. 4(b), 4(b'). Of the inclined guide means, at least only the guide face 15 will serve to release the linkage part 10b' and guide it. When pressing is stopped, the linkage part 10b' is automatically moved and guided along the outer front face 12b by the elasticity F. As a result, the linkage part 10b' is released from the projection 12 as shown in Fig. 2, so that the bulb 8 can be removed from the reflector 4. As mentioned above, the erected and folded portions 10d, 10e of the spring 10 are directed perpendicularly to the flange 4a when the linkage part 10b' of the spring 10 is brought into contact with the inclined guide face 14b or when the linkage part 10b' is engaged with the holding portion 14a. Therefore, since the push portion 10c is pressed perpendicularly to the flange 4a in order to hold the U-shaped portion 10b of the spring 10 in the holding portion 14a or release it therefrom, the pressing for holding and releasing the spring 10 is always carried out in the direction perpendicular to the flange 4a. This results in a simple operation. According to the bulb holding structure arranged as mentioned above, regardless of a narrow space limiting a satisfying movement of an operator's hand, the free end port ion of the spring is easily caught by or released from the holding portion disposed on the back side of the reflector with slight force and without observing the free end portion. Further, the spring is stably placed in the reflector.

Claims: A reflector assembly including a bulb inserting hole (7a) formed through a reflector (2), a spring holding projection (12) and a spring fixing portion (11) each disposed on a back side (2c) of said reflector (2) on opposite sides of said bulb inserting hole, said spring holding projection having a spring holding claw (14), a spring (10) having a base end (10a) which is pivotally fixed to said spring fixing portion (11), a free end to be connected to or disconnected from said spring holding projection (12), a U-shaped portion (10b) formed at said free end of the spring, said U-shaped portion being caught and held by said claw (14), and a curved portion (10f) formed at the middle of said spring, for fastening a bulb (8) between said curved portion and the back side of said reflector, a catching guide face (14b) formed in said spring holding projection (12) for guiding said U-shaped portion (10b) to said claw (14), and inclined guide means (15, 16, 17) formed in said spring holding projection, for releasing said U-shaped portion from said claw, characterized in that a U-shaped concavity (13) is formed in an outer face (12b) of said spring holding projection, said outer face (12b) being exposed in a direction opposite to said spring fixing portion (11), said concavity (13) including a pair of side grooves (13a, 13b) elongated in a direction in which a U-shaped push portion (10c) is pressed to engage said claw (14), and a linking groove (13c) linking ends of said side grooves to each other, wherein the other ends of said side grooves opposite said linking groove are open and said claw (14) is formed in said concavity (13), and that said inclined guide means includes an inclined guide face (15) which extends from a bottom of said concavity (13) and is inclined in the same direction as said catching guide face (14b). A reflector assembly according to claim 1, characterized in that the tip of said claw (14) is located below said outer face (12b) of the projection, when a lighting portion (8a) of said bulb defines a top area. A reflector assembly according to claim 2, characterized in that said U-shaped concavity (13) is enclosed by walls contiguous to said side grooves (13a, 13b) and opposite to each other with respect to said claw (14) and by a wall linking said side walls (13a, 13b) to each other; said releasing guide means includes first and second inclined guide faces (15, 16), said first inclined guide face (15) being formed so that said linking wall is inclined from the base of said claw (14) to said outer face (12b) of the projection and in an opposite direction to said claw (14), said second inclined guide face (16) being formed so that a part of either of said side walls (13a, 13b) is inclined from a place facing a spring holding portion of said claw (14) to said outer face and in a direction approaching the other side wall; and said U-shaped portion (10b) of the spring (10) is disengaged from said spring holding portion of the claw (14) and is guided along said first and second guide faces (15, 16) by pressing said U-shaped push portion (10c) of the spring (10) against the elasticity of said spring (10). A reflector assembly according to claim 3, characterized by a third inclined guide face (17) formed so that a part of the other side wall is inclined from the bottom of said spring holding concavity (13) to said outer face (12b) of the projection in a direction opposite to said second guide face (16). A reflector assembly according to claims 1 to 4, characterized in that said spring (10) includes an erected portion (10d) bent in the opposite direction to said curved portion (10f), and a folded portion (10e) turned up from the tip of said erected portion (10d) to a point corresponding to the root of said erected portion (10d), said U-shaped portion (10b) of the spring (10) being contiguous to said folded portion (10e), said push portion (10c) being formed at a joint between said erected and folded portions (10d, 10e). A reflector assembly according to claim 5, characterized in that said projection (12) juts out in a direction perpendicular to a flange (8c) of the bulb (8), said erected and folded portions (10d, 10e) are elongated in a direction in which said projection juts out when said U-shaped portion (10b) of the spring (10) is brought into contact with said spring catching guide face (14b) and when said U-shaped portion (10b) is held by said spring holding portion (14a) of the claw (14) and said push portion (10c) is pressed in a direction perpendicular to said flange (8c) of the bulb (8) in order to engage said U-shaped portion (10b) with said claw (14) or disengage it from said spring holding portion (14a).

Inventors: CHIKADA AKIRA, CHIKADA, AKIRA, CHIKADA, AKIRA C/O ICHIKOH INDUSTRIES LTD.,
Applicants: ICHIKO INDUSTRIES LTD, ICHIKOH INDUSTRIES LIMITED
Application year: 1993
Main classification: F21M7
IPC codes: F21V19, F21S8