GB2205986A - Base for a tape recorder - Google Patents

Abstract

A tape recorder base comprises a main base 1 of pressed metallic sheet, and a secondary base 2 of synthetic resin material connected by complementary engaging means 11, 21, 12, 22, and then screwed together. The respective bases support components as specified, and a projection (13) (Fig 1) extends from main base 1 to support ground wire spring (8) for suppressing effects due to static electricity. Operational life of ground wire spring 8 is enhanced. Also, the combination of the main and secondary bases can strengthen the structure, simplify assembly, and increase dimensional accuracy. <IMAGE>

Description

BASE FOR A TAPE RECORDER This invention relates to a base for a tape recorder.

The invention is particularly though not exclusively concerned with the combination of a metallic base and a synthetic resin base in which combination a ground wire spring is secured so as to eliminate static electricity. The combination of the metallic and synthetic resin bases not only allows the ground wire spring to be fixed to eliminate or reduce static electricity, but also can extend the working life of the ground wire spring. The structure of the spring may be simplified and its temper intensified to avoid bending and to reduce the cost and to simplify assembly. At present, the base structure of typical current tape recorders comprises two or more base boards, to achieve better precision and to simplify the procedures for manufacture and for assembly.

Nevertheless, there are still some shortcomings in base design and function.

Firstly, there is the shortcoming of poor assembly. In traditional tape recorders, the bases are assembled together either with screws, or by interlocking base board pieces of different material and then fixing them with screws, to clamp them together and to achieve better precision. However, it is common knowledge that the former method (using screws alone) provides poor precision, while the latter might achieve the expected result, but due to the complexity of the assembly and installation the costs will certainly increase. It is uneconomic in large quantity manufacturing and the connection may become loose during the complicated assembly procedure.

Secondly, the bases have the shortcoming in that it is not possible entirely to eliminate static electricity. During operation, the axle of the reel is isolated from the metallic cover as well as the external components. Therefore the friction from rotation and from the constant rubbing contact of the magnetic tapes generates negative effects such as static electricity which results in interference or jamming of the signals.

The traditional measure to solve this problem is to connect a ground wire to the metallic cover to eliminate the static electricity. However, in this method a metallic board associated with the magnetic head is restored to its original position. The metallic cover is tightly attached. The metallic cover is then fixed to the ground wire spring on the synthetic resin board to ensure the rotation of the ground wire. But, in operation, owing to the attachment of the magnetic head to the metallic plate, the magnetic head must constantly bear the pressure exerted by the ground wire spring and this results in spring fatigue. Also, the spring may become loose and fall or fail. Furthermore assembly is complex and it is possible that the connecting point of the synthetic resin and the ground wire spring may be torn off under torque.Consequently, the above mentioned factors mean that the arrangement often does not achieve good results in eliminating static electricity. In view of the aforesaid shortcomings of the traditional tape recorders a new type of base structure is herein disclosed.

According to one aspect of this invention, there is provided a base assembly for a tape recorder comprising a metallic base member, a base member of synthetic material, said metallic base member supporting the tape recorder driving motor, said base member of synthetic material supporting the function keys, the release device and the winding reels, and complementary engaging means provided on the metallic base member and the base member of synthetic material for allowing connection of said base members one on top of the other.

The base disclosed herein comprises a metallic main base and a synthetic resin secondary base, and the main base and the secondary base are assembled by initially connecting the bases by means of complementary push and press latches and bolts and then completing the connection by fastening the bases with screws, so as to solve at least some of the problems which result from the connection of more than two pieces of boards, in terms of the manufacturing and assembly time. The metallic base may have associated therewith an elongate projection.

In the preferred embodiments the elongate projection on the main base can be either fixed or shifted in positions so as to reduce the external load on the ground wire spring, to ensure the long lasting endurance of the ground wire, and to eliminate static electricity.

The invention will now be described by way of example, reference being made to the accompanying drawings, in which: Figure 1 is a bottom plan view of an embodiment of tape recorder base assembly constructed according to the invention; Figure 2 is a view illustrating the main base and the secondary base of the assembly of Figure 1 prior to assembly, and Figure 3 is a bottom plan view of the main base of the assembly of Figures 1 and 2.

Referring initially to Figure 1, there is illustrated a bottom plan view of the base assembly of a tape recorder. The assembly comprises a metallic main base 1 formed in a press in a high pressure pressing or stamping operation, a driving motor 3 secured by a bracket to the metallic base 1, a fixed rotating wheel 4 drivingly connected to a gear wheel 5 by means of a belt, a ground wire spring 8, a synthetic resin secondary base 2, several function keys 6, a release device 7, a metallic cover on a wincing axle 9, and a metallic board 10 for supporting the magnetic head.

The ape recorder base also includes further components but these will not ' described in detail.

Referring to Figure 2, the metallic main base 1 and the synthetic resin secondary base 2 are shown prior to assembly. The secondary base 2 includes adjacent its front edge two hook-like bolt elements 21 which cooperate with corresponding apertures 11 provided on the front edge of the main metallic base. Each hook-like bolt has an enlarged head portion which may pass through and lock with the apertures 11. Also, the two sides of the secondary base include two projections 22 which cooperate with associated L shaped hooks 12 which upstand from the metallic main base 1.The arrangement is such that when the secondary base is brought down into contact with the metallic main base and then pushed forwardly relative thereto in the position shown by the arrows on Figure 2 the abutments 22 will cooperate with the hooks 12 and the hooks 21 on the secondary base will pass through and lock into apertures 11 on the metallic base, thus securing the bases together.

Following this operation, the two bases are secured by means of screws extending through apertures provided in the metallic base into the material of the secondary base.

Referring now to Figure 3, there is shown a bottom plan view of the metallic main base. Projecting downwardly from the metallic mainbase is an elongate, generally T shaped projection 13 intended to fix the bases and to assist in securing the ground wire spring 8 to eliminate static electricity generated during rotation of the tape reels.

In Figures 1 and 3, the function keys 6 are mounted on the metallic mainbase 1 and the synthetic resin secondary base 2 properly to locate the function keys and to prevent looseness. Although the synthetic resin secondary base requires high dimensional accuracy, it may easily be bent or distorted. Thus the metallic mainbase 1 reinforces the secondary base and may reduce its costs. In addition, the elongate projection 13 on the bottom of the metallic mainbase can assist location of the ground wire string 8 and serve to eliminate or at least reduce static electricity generated by rotation of reels.

In a traditional tape recorder, the ground wire spring 8 is attached to the magnetic head board 10 and the metallic cover on the winding reel 9 to eliminate static electricity. However, the frequent pushing of the magnetic head board during operation of the tape recorder and the constant external pressures subject to the ground wire spring to fatigue loadings which results in a loose connection and, eventually, static electricity may not be fully eliminated.

In the disclosed arrangement therefore the ground wire spring is laid between release device 7 and the metallic cover on the winding reel and the spring is supported by the elongate projection 13. In this manner, the ground wire spring 8 merely bears against the release device without being subjected to external pressures. In this way, it is ensured that the connection eliminates static electricity build-up.

The embodiment of tape recorder base assembly as described above is of enhanced precision, is more simple to manufacture and cheaper to produce. Furthermore, the structure of the base assembly is strengthened and thus the operational life of the base is extended.

Claims (8)

1. A base assembly for a tape recorder comprising a metallic base member, a base member of synthetic material, said metallic base member supporting the tape recorder driving motor, said base member of synthetic material supporting the function keys, the release device and the winding reels, and complementary engaging means provided on the metallic base member and the base member of synthetic material for allowing connection of said base members one on top of the other.

2. A base assembly according to claim 1 wherein said complementary engagement means includes hook elements provided on one base member adapted lockingly to engage a projection or aperture on the other base member.

3. A base assembly according to claim 1 or claim 2 which further includes screws adapted to connect the base members.

4. A base assembly according to any one of the preceding claims wherein a ground spring electrically connects an electrically conducting element associated with one of the tape recorder reels and said metallic base.

5. A base assembly according to claim 4, wherein a projecting element forming part of the metallic base serves a fixing purpose to release the ground wire spring on the release device.

6. A tape recorder comprising a main base made of metallic sheet formed by a pressing or stamping operation and a secondary base, integrally formed of plastic material or a synthetic resin wherein the main metallic board supports the driving motor, a gear wheel and other components, the synthetic resin secondary base supports the magnetic head function keys, the release device and winding reels and the main and secondary bases are connected by means of locking means provided on the secondary base, which engage complementary locking means on the main base and a ground wire spring extends between a projection on the metallic base and a conducting element associated with one of the tape recorder reels.

7. A base assembly for a tape recorder substantially as hereinbefore described, with reference to and as illustrated in, any of the accompanying drawings.

8. Any and all novel features and combination and subcombinations thereof disclosed.