GB2201842A - Motor mounting assembly - Google Patents

Abstract

A motor mounting assembly comprises a motor having two L-shaped hooks 12, 13 and a mounting frame 20 having two apertures 25, 26 for receiving the hook elements. Each aperture is provided with a slot along which the hook elements may pass to lock, by means of resilient portions 28, the motor to the mounting frame. Detents 14, 15 are engaged by projections 24 on resilient arms 22, 24. <IMAGE>

Description

MOTOR MOUNTING ASSEMBLY This invention relates to a motor mounting assembly for mounting a motor on a support frame. In particular, though not exclusively, the invention is concerned with assemblies for mounting small electric motors such as are used for example in tape recorders or small toys.

Conventionally the motor is secured to the mounting frame by means of screws, or by an indirect mounting in which one part of the mounting is screwed to the motor whilst the other part of the mounting is screwed to the support frame. The indirect fixing method is often used in tape recorders or toys. In either method, however, many screws are needed to mount the motor. Of course, the cost of the screws themselves is insignificant, but the need to insert and tighten the scews adds significantly to the cost of manufacture. Also more than two screws are used in most domestic electrical machines. The added cost is clearly apparent. As well as adding to the cost of manufacture it will be understood that electric motors tend to generate an external magnetic field when operating.The screws may interfere with this field and this may result in vibration of the screws, together with an induced current being transmitted into the mounting frame by the screws, and interference of the magnetic field of the motor.

The general solution to the above problem is to insert a plastics cushion between the motor and the support frame to attempt to damp the vibration when the motor is running. Also, to reduce the electrical noise generated by the magnetic interference an integrated circuit filter is installed or an earth connection is applied. However, this increases the manufacturing costs and thus manufacturers seldom use these palliative measures.

The applicant, from his experience gained in domestic electrical machines and assembly of toy motors from western countries, Japan and other advanced countries, has created a motor mounting assembly for securing a small motor to a fixing frame in which the magnetic interference and vibration are reduced. Furthermore, in the assembly, the motor is secured without using any screws or rivets.

According to one aspect of the invention, there is provided a motor mounting assembly including a motor having first complementary engaging means and a support frame having second complementary engaging means, said engaging means being arranged such that said motor is assembled to said support frame by a relative turning movement through a part of one revolution.

According to another aspect of the invention, there is provided a motor mounting assembly including a motor and a support frame, said motor including two generally L-sectioned hook elements projecting from an end face, said support frame including a support surface for said end face, said support face including two apertures each adapted to pass a respective hook element and each having a slot portion of reduced width extending in a given circular direction, said motor being assembled with said support frame by passing said hook elements through said apertures and turning said motor relative to said frame so that the limb portions of the hook elements adjacent said end face pass into said slots thereby to secure said motor in a locked position.

The invention will now be described by way of example, reference being made to the accompanying drawings, in which: Figure 1 is an exploded schematic view of a motor mounting assembly prior to assembly; Figures l(a) and l(b) are detailed views of items contained in circles A and B respectively of Figure 1, and Figure 2 is a view from below of the assembled motor mounting assembly.

Referring to the Figures, the assembly comprises a motor 10 and a separate mounting frame 20. The motor 10 includes a eylindrical shell 11 having an end face surrounding the spindle of the motor. From the end face of the shell 11 project two L-shaped hooks 12 and 13 (see Figure 1(a which are formed by pressing. On the inner surface of each portion of the hooks which lies parallel to the end face is provided a fixed pip 16, 17 respectively. The end face of the shell 11 also includes two detent recesses 14 and 15.

Referring now to the mounting frame 20, this includes a support surface 21 for the end face of the shell 11 and an upstanding peripheral cylindrical wall of similar internal diameter to the external diameter of the shell 11. The support surface is formed to have two diametrically opposed spurs 22, 23 each having a protruding pip 24 on the free end. The spurs are each resiliently movable out of the plane of the support surface 21.

The surface 21 is also provided with two diametrically opposed apertures 25, 26 equi-spaced from the two spring spurs 22, 23.

Each aperture includes a generally rectangular section and a clockwise extending circular slot portion. Merging with each slot portion is a further slot portion 25', 26' respectively which together with the respective slot portions define a spring stop 27, 28. Two detent holes 29, 30 are provided on the lower surface of the support frame 20, adjacent the tail ends of the apertures 25 and 26 respectively.

In order to assemble the above arrangement, the L-shaped hooks 12 and 13 are passed through the respective apertures 25 and 26 and the motor is turned clockwise relative to the support surface 21 so that the hooks 12 and 13 pass along the slot portions of the aperture 25, 26.

As this occurs, the two spring stops 27 and 28 are urged inwardly. Only pips 16 and 17 contact the lower surface of the fixed mounting frame 20, and thus interference during assembly will be reduced. When the L-shaped hooks on the motor shell 11 reach the ends of the respective apertures 25, 26, the pips 16 and 17 engage the detent holes 29 and 30 in the lower surface of the support frame 20 and the spring stops 27 and 28 will return to their equilibrium positions to prevent anticlockwise movement of the motor relative to the support frame. In addition, the pips 24 on the two spring spurs 22 and 23 will locate in the detent recesses 14 and 15, also to effect locking. Thus, the motor is securely attached to the mounting frame 20. The spring stops 27 and 28 serve as ratchets to lock the hook-shaped elements against further movement when they reach the end of the grooves.During the initial part of movement towards the locking position, the stops may be urged inwards either by the portions of the hook elements adjacent the end face of the motor or by the pips 16, 17.

The mounting frame is made of electrically insulating material and the two spring spurs 22, 23 are resiliently deformable. When the motor is running, the resultant magnetic-electric induction will not cause magnetic interference. Also, the spring bias applied by the spring spurs 22 and 23 will reduce the vibrations generated by operation of the motor.

The detent holes 29, 30 may be provided on the free ends of the spring stop arms 27, 28.

In conclusion, the apparatus illustrated allows a quick assembly of an electric motor to a support frame without the need for screws. The magnetic and induced electric interference are reduced, and the vibration is also reduced. The assembly may be used widely in the construction of tape recorders, domestic appliances incorporating small electric motors or toys.

Claims (9)

1. A motor mounting assembly including a motor having first complementary engaging means and a support frame having second complementary engaging means, said engaging means being arranged such that said motor is assembled to said support frame by a relative turning movement through a part of one revolution.

2. A motor mounting assembly including a motor and a support frame, said motor including two generally L-sectioned hook elements projecting from an end face, said support frame including a support surface for said end face, said support face including two apertures each adapted to pass a respective hook element and each having a slot portion of reduced width extending in a given circular direction, said motor being assembled with said support frame by passing said hook elements through said apertures and turning said motor relative to said frame so that the limb portions of the hook elements adjacent said end face pass into said slots thereby to secure said motor in a locked position.

3. A motor mounting assembly according to claim 2, wherein each of said motor and said support frame includes complementary detent means for locking said motor in said locked position.

4. A motor mounting assembly according to claim 3, wherein the limb portions of the hook elements remote from said end face include detent means engageable with complementary detent means on said support frame.

5. A motor mounting assembly according to claim 3 or claim 4, wherein said support face includes two spring spur elements each extending in a given circular direction and each including a detent means engageable with complementary detent means on the end face of the motor.

6. A motor mounting assembly according to any one of claims 2 to 5, wherein each of said slot portions is formed to provide an elongate ratchet portion adapted to deform to allow movement of said motor to its locked position but to return to a blocking position to prevent movement of said motor out of its locked position.

7. A motor mounting assembly according to claim 6, wherein said elongate ratchet pbrtion includes detent means engageable with detent means on the end face of the motor.

8. A motor mounting assembly substantially as hereinbefore described with reference to and as illustrated in, any of the accompanying drawings.

9. Any and all novel features and combinations thereof disclosed herein.