JPS6239598Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a slip ring that is attached to, for example, a rotating head of a VTR to supply electrical signals to the rotating head.

Generally, home VTRs use a helical scan method that uses a rotating head, but this rotating head is supplied with recording signals and bias current.
Some devices use a slip ring to extract the reproduced signal, and a tongue-shaped brush is slidably contacted with the slip ring to maintain electrical connection between the rotary head and the main body.

By the way, this type of slip ring usually has a cylindrical or rod-shaped support shaft protruding from a metal base, and a ring-shaped slip ring element with a highly conductive sliding surface formed on the outer periphery of the support shaft. A necessary number of slip-ring elements are inserted and overlapped with each other, and these slip-ring elements are integrally fixed to the base by a screw threaded onto the tip of the support shaft.

However, in conventional slip rings of this type, the ring diameter of the slip ring element is designed to be relatively large, and the inside is filled with insulating resin, so that the slip ring element is connected to the ring member that forms the sliding surface. This has the advantage that sufficient voltage resistance characteristics can be ensured between the lead wire and the support shaft or base (both of which are at ground potential).

However, in recent years, there has been a trend to use precious metal materials such as gold, platinum, and silver for the ring members that make up the slip ring element in order to reduce the contact resistance between the slip ring and the brush. There are problems that must be addressed. However, if miniaturization is carried out carelessly, a sufficient distance between the ring member and the support shaft cannot be secured, resulting in a new problem of dielectric breakdown between the lead wire connected to the ring member and the support shaft. It is something. Incidentally, a high voltage of about 700 to 800V is usually applied to these slip-ring elements.

The present invention was developed based on these circumstances, and its purpose is to provide a slip ring that can ensure sufficient voltage resistance characteristics even when the slip ring element is downsized.

In order to achieve such an objective, the present invention has been developed in which an insulating tube is fitted over the entire length of a metal support shaft that supports a slip-ring element, and the slip-ring element is made of resin and has a groove on its inner periphery. The cylindrical base of is insert-molded integrally with a ring member forming a conductive sliding surface, and the terminal portion projecting in a folded manner from a part of the ring member is in close proximity to the groove bottom of the groove portion. It is characterized by being accommodated in the groove, and even if the slip ring element is made small, sufficient voltage resistance can be ensured between the lead wire and the support shaft, and a highly reliable slip ring can be obtained. It is something.

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings.

FIG. 1 shows a partial sectional view of a slip ring according to the present invention, and FIG. 2 shows an exploded front view showing its assembled state. In the figure, 1 is the flange part 2, 2
This is a metal base that integrally has 1
A cylindrical support shaft 4 having a threaded groove 3 carved in the inner circumferential portion is integrally provided on the upper surface of the central portion thereof. An insulating tube 5 made of, for example, polyester resin is fitted onto this support shaft 4 over its entire length.

Reference numeral 6 denotes a slip ring element that forms a sliding surface 7 on the outer periphery, and a highly conductive ring made of a noble metal material on the outer periphery of a resin cylindrical base 9 with a flange 8 integrally formed on the lower end periphery. The member 10 is integrally fitted by insert molding.

In addition, four grooves 11 are provided on the inner circumferential portion of the cylindrical base 9 and are opposed to each other with the axis in between. Terminal part 1 folded back
0a is accommodated in a state close to the bottom of the groove as clearly shown in FIGS. 1 and 3, and a lead wire 12 is welded to this terminal portion 10a by spot welding or the like.

In this embodiment, three slip-ring elements 6 are inserted into the support shaft 4 and overlapped with each other, and a screw 13 screwed into the tip of the support shaft 4,
It is integrally fixed to the base 1 by a washer 14 and a spring washer 15.

In addition, each ring member 1 of the slip ring element 6...
The lead wires 12 connected to the base 1 are led out from the bottom of the base 1 through through holes 16 formed in the base 1.

According to such a configuration, even if the ring diameter of the slip ring element 6 is made smaller by reducing the outer diameter of the cylindrical base 9, the terminal portion 10a can still fit into the groove formed in the inner circumference of the cylindrical base 9. Since it is housed in 11, its location will not change. Therefore, even if the slip ring is made smaller by reducing the ring diameter, the terminal portion 10a is smaller than the ring diameter.
and the support shaft 4 are relatively large apart. Therefore, due to the synergistic effect of this and the fact that the insulating tube is fitted around the outer periphery of the support shaft 4, even if a high voltage is applied to the ring member 10 of each slip ring element 6, the ring Terminal part 1 of member 10
0a and the support shaft 4, between the welded portion of the lead wire 12 to the terminal portion 10a, or between the exposed conductor portion of the lead wire 12 itself and the support shaft 4, there is no possibility of dielectric breakdown, and the withstand voltage characteristics are significantly improved. can be done.

Therefore, compared to conventional slip-rings of this type, the slip-ring element 6 itself can be made sufficiently smaller, and the amount of expensive precious metal materials used can be reduced, and the insulating tube 5 required for this purpose can be reduced. Since the slip ring itself is extremely inexpensive, it is possible to significantly reduce the manufacturing cost of the slip ring.

In this embodiment, the slip ring elements 6 are stacked in three stages, but the number of slip ring elements 6 can be increased or decreased as necessary.

Furthermore, in this embodiment, as an example of the application of the slip ring, the case where it is used in the rotating head of a VTR has been explained, but it is not limited to this application only, and it can also be used when supplying relatively high voltage electrical signals to a rotating body, etc. It can be widely applied when it is necessary to ensure voltage resistance characteristics.

As explained above, even if the slip ring of the present invention is made smaller by reducing the ring diameter of the slip ring element, the distance between the terminal portion of the ring member and the support shaft is relatively large compared to the ring diameter. Since they are separated by a large distance, this effect is combined with the effect of fitting the insulating tube on the support shaft, resulting in sufficient withstand voltage characteristics. Therefore, even if expensive precious metals are used for the ring member, the amount used can be reduced. Furthermore, since the work of welding the lead wire to the terminal part can be performed within the groove of the cylindrical base, there is an advantage that a large work space can be secured.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing one embodiment of the present invention;
FIG. 2 is an exploded front view showing the assembled state of the same embodiment;
FIG. 3 is a top view of the slip ring element of the same embodiment, and FIG. 4 is a sectional view taken along line X-X' of the same slip ring element. DESCRIPTION OF SYMBOLS 1... Base, 4... Support shaft, 5... Insulating tube, 6... Slip-ring element, 7... Sliding surface.

Claims (1)

[Scope of Claim for Utility Model Registration] In a slip ring in which an annular slip ring element forming a conductive sliding surface on the outer periphery is fitted and supported on a metal support shaft, the support shaft extends over its entire length. An insulating tube is fitted over the slip ring element, and a resin cylindrical base having a groove on the inner circumferential surface is insert-molded integrally with the ring member forming the sliding surface, and
A slip ring characterized in that a terminal portion projecting in a folded manner from a part of the ring member is accommodated in the groove portion in a state close to the groove bottom of the groove portion.