JPS6041657Y2 - Plug with built-in fuse for automobile cigarette lighter socket - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a plug with a built-in fuse that is used when using an automobile's power source from an automobile's cigarette lighter socket.

As is well known, this type of plug has various shapes, but basically, it has a cylindrical shape and has a terminal that is slidably protruded from the tip of the plug and is biased by a coil spring or the like. The plug is provided with terminals that are elastically and slidably protruded from the side of the plug, and the power source of the automobile is taken out by a cord connected to each terminal.

Furthermore, in recent years, plugs have been developed that include a built-in glass tube fuse that is interposed between a terminal located at the tip of the plug and a connecting cord in order to prevent damage to equipment due to short circuits during connection.

Plugs with built-in fuses inherently require replacement of the fuse, and therefore the plug is constructed so that it can be disassembled for the purpose of replacing the fuse. Broadly speaking, there are two types: one in which the plug is divided in the axial direction, and the other in which only the portion including the terminal protruding from the tip of the plug is separated.

In the former disassembled configuration, when the plug is split, the protruding terminals housed inside the plug that are biased in a spring-like manner and the side terminals that have spring-like properties pop out of their predetermined positions, making reassembly difficult and causing the spring-loaded side terminals to pop out. It was easy for parts to be lost due to missing the target.

On the other hand, in the latter case, the side terminals, connection cords, etc. are contained and fixed as a whole, and only the protruding terminal side part is separated, so the Although it is possible to prevent disassembly from disassembling already destructive parts, as mentioned in the explanation of the present invention described later, the terminal protruding from the tip should not be used at the tip of the plug when not in use. The plug must be formed so that it protrudes as much as possible from the socket and is pushed inward according to the extent to which it is inserted into the lighter socket during use, and the entire outer sheath of the plug must be made of a synthetic resin mold from the viewpoint of productivity. Because the protruding terminals are made by molding, they are prevented from moving only toward the front end of the plug when separated, while they are completely free to move toward the rear end of the plug. Therefore, there is a risk that the protruding terminal may come off the tip end of the jacket and be lost during separation for replacing the fuse.

Therefore, the purpose of the present invention is to prevent the protruding terminal of the plug, which is formed so that the fuse can be replaced by separating the front end of the plug, from falling off from the front end of the plug jacket, which is separated for fuse replacement. This invention was devised to provide a plug with a built-in fuse that can be reliably prevented, extremely easily made, and manufactured at low cost.Hereinafter, embodiments of the invention will be described with reference to the drawings.

1 and 2 are views showing the general configuration of a plug according to an embodiment of the present invention, which has a generally curved part for connection with a terminal located on the side wall of a cigarette lighter socket of an automobile. A U-shaped side terminal 1 and a fuse terminal 3 for connecting to one end of the glass tube fuse 2
and one end of the cord 4 connected to the side terminal 1 and the terminal 3, respectively, are substantially integrated into the space, and the fuse 2 is detachably inserted from the axially distal end side. a plug body 6 having a fuse 2 therein; a protruding terminal 7 for connecting to another terminal located at the bottom end of the cigarette lighter; and a plug body 6 having a fuse 2 therein; A coil spring 8 whose one end is fixed and whose other end is connected to the other end of the fuse 2, and a large-diameter cavity 9 formed with a female thread for removably screwing into the tip of the plug body 6, and a protrusion. An opening 11 having a generally convex cross-sectional shape consisting of a small-diameter cavity 10 for movably receiving the terminal 7 in the axial direction, and from which the distal end portion 7a of the protruding terminal 7 can freely enter and exit. Plug tip 1 having
2, and a blocking ring 13 having a flat washer shape for holding the protruding terminal 7 in the small diameter space 10 located on the tip side of the plug tip 12 and limiting the amount of movement of the protruding terminal 7 for reasons that will become clear later. It consists of

The feature of the present invention is to limit the movement of the protruding terminal 7, and in particular, to prevent the movement of the protruding terminal 7 from the plug body 6 to the plug tip 12 in order to replace the fuse, etc.
The blocking ring 13 is made of fiber sheet, soft synthetic resin, paper, felt, rubber, etc. to prevent the protruding terminal 7 and the spring 8 fixed to it from falling off from the plug tip 12 when the terminal is removed. It is made of a flat washer shape having an opening 13a in the center of a thin plate-like member having appropriate flexibility or elasticity, and the dimensional relationship in the flat shape is as follows for reasons that will become clear from the following: As shown in FIG. 3, the outer circumferential edge 13b of the blocking ring 13 is sized suitably larger than the essential circumferential edge 9a of the large diameter cavity 9 of the plug tip, while the inner circumferential edge 13c of the opening 13a. The outside of the blocking ring 7b has a size suitably larger than the opening 11 for preventing the tip 7a of the protruding terminal 7 from passing through the opening 11 of the plug tip 12 and coming off outward. It has dimensions selected to be suitably smaller than the circumferential edge and to allow axial movement of the spring 8 through the opening 13a.

In the thus formed blocking ring 13, as shown in FIG. The spring 8 is inserted into the opening 13a of the blocking ring 13 and abuts the transition wall 12a for defining a small diameter cavity 10 into the large diameter cavity 9 of the plug tip 12. Due to the flexibility or elasticity of the blocking ring 13, it is substantially fixed in the final pushed-in position, and the axial movement of the protruding terminal 7, more precisely, the blocking ring portion 7b is prevented by a small diameter. This means that it can be limited to the space 10.

In this way, the plug terminal part 7, in which each part is assembled while allowing limited movement of the protruding terminal 7, is connected to the plug body with the fuse 2 inserted into the cavity 5, as shown in FIGS. 5a and 5b. 6 to complete the cigarette lighter plug.

At this time, the spring 8 is compressed to urge the protruding terminal 7 to protrude from the tip of the plug and urge the fuse 2 toward the rear end to ensure a secure connection with the terminal 3. When the spring 8 is further compressed so that the protruding terminal 7 is pushed inward when inserted into the stopper ring 14, the opening 13a of the blocking ring 13 does not impede its contraction (or expansion) movement.

As mentioned above, the plug body and tip of this type of plug are made by mold molding of synthetic resin members from the viewpoint of insulation and productivity, so the plug tip in particular has a shape that can be removed from the mold. And,
It is impossible to create a space that can limit the movement of the protruding terminal, and even if a space that can limit the movement of the protruding terminal is created, it is impossible to mount the protruding terminal therein.
Therefore, according to the present invention, the movement of the protruding terminal can be reliably limited by the simple and inexpensive means of applying a blocking ring, and the fuse can be removed without substantially increasing the manufacturing cost. It is possible to provide a plug that can prevent the protruding terminal from falling off or being lost during replacement or inspection.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing an embodiment of the present invention. FIG. 2 is a partial sectional view of the structure shown in FIG. 1 in an exploded state. FIG. 3 is a diagram for explaining the blocking ring, which is a feature of the present invention. FIG. 4 is an enlarged partial cross-sectional view of what is shown in FIG. 1. FIGS. 5a and 5b are views similar to FIG. 4, each showing a state of use. 1...Side terminal, 2...Glass tube fuse, 3...Fuse terminal, 6...Plug body, 7...Protrusion Terminal, 8... Coil spring, 9... Large diameter cavity, 10...
...Small diameter cavity, 12...Plug tip, 13
...Block ring.

Claims (1)

[Scope of utility model registration request] In a plug with a built-in fuse for extracting power from a car's cigarette lighter socket, a glass tube fuse 2 is used to cut off current in the event of an overcurrent, and a side terminal 1 is used to connect to a terminal on the side wall of the cigarette lighter socket. , a fuse terminal 3 for connecting one end of the fuse 2 to the bottom end of the cavity 5 into which the glass tube fuse 2 is removably inserted in the axial direction from the tip end side of the plug, the side terminal 1 and the fuse. A plug body 6 having a cord 4 each having one end connected to the terminal 3, a protruding terminal 7 substantially integral with a coil spring 8 for connection to a terminal at the bottom end of a cigarette lighter socket, and a protruding terminal. 7 is generally defined by a small diameter cavity 10 formed to allow axial movement of the plug and a large diameter cavity 9 formed to be removably screwed into the tip of the plug body 6. A plug tip 12 having a convex cross-sectional configuration and a transition wall 12 a between the large diameter cavity 9 and the small diameter cavity 10 so as to substantially confine axial movement of the protruding end 7 within the small diameter cavity 10 . It is composed of a blocking ring 13 disposed at a position where it abuts,
The blocking ring 13 has a generally flat washer shape with an opening 13a in its central portion made of a suitable flexible or elastic material such as a fiber sheet or rubber;
In addition, the outer peripheral edge 13b of the blocking ring 13 is connected to the plug tip 1.
2, while the circumference 813 c of the opening 13 a of the blocking ring 13 is
is sized such that the coil spring 8 can freely move and pass through and can be prevented from passing through the blocking ring 7b for preventing the protruding terminal 7 from escaping outward through the opening 11 from the plug body 12. A plug with a built-in fuse.