Patent GB-628056-A (GB)
Title: A new or improved teeth-cleaning appliance
IPC: A61C17/26
Filed: 1947-05-09
Abstract: 628,056. Rotary tooth brush. WIGHT, R. S., and SALTMARSH, J. A. May 9, 1947, No. 12633. [Class 19] In a tooth cleaning appliance in which the brush is mounted on a spindle which is connected at its inner end to a driving spindle mounted within a cylindrical casing, the outer end of said brush spindle being supported by the outer end of a shield which is secured at its inner end to said cylindrical casing, the driving spindle is driven by the frictional engagement of a driving cone with one or other of a pair of conical members secured to the driving spindle. The device may comprise a casing 10 in the lower part of which is mounted an electric motor (not shown) and the motor spindle 11 carries at its end a driving cone 12 which frictionally engages one or other of a pair of conical members 13 mounted on the driving spindle 14. The latter bears at one end on a seating formed on a member 15 slidably mounted in the casing 10 and is supported at its other end by thrust bearings 16 at the open end of a cylindrical casing 17 which is slidably mounted in the casing 10. The casing 17 and the member 15 are rigidly connected by a bracket 18. The member 15 is provided with a milled knob 20 and on pushing in the latter against the action of a spring 21 the driving cone 12 is brought into engagement with the left hand cone 13 whilst on releasing the knob the right hand member engages the driving cone thus reversing the rotation of the spindle 14. A substantially semi-cylindrical shield 23, which may be rotatably adjustable about the brush spindle 25, is detachably connected to the casing 17 and carries one end of the brush carrying spindle 25 which is detachably connected at its other end with the driving spindle 14. The assembly 17, 18, 20, 23 is rotatable within the casing 10 up to the limits imposed by the spindle 11 thus enabling the back of the teeth to be cleaned while the sheath 23 protects the back of the mouth, the assembly being held in the desired position by the spring-loaded ball 19. In the form shown in Fig. 3 the driving cone is adapted to be moved into frictional engagement with one or other of the conical members 13. In this case the conical members 13, the spindle 14 and the casing 17 are stationary, the latter being screwed into the casing 10 while the spindle 14 bears on a seating formed in the opposite side of the casing. The motor spindle 11 carries a toothed wheel 27 which engages a toothed wheel 28 mounted on a spindle 29 attached to the cone 12 and carried by a frame 30 which is pivotally mounted on spindle 11 so that the driving cone may be moved in an arc about the motor spindle while maintaining the toothed wheels in mesh. The frame may be moved by means of a cranked bar 31 extending through the casing 10 and formed with a pin 33 which engages a slot formed in an arm of the frame 30. The members 13 may be damped while the driving cone is out of engagement therewith by means of a damper 35 carried by a lever 36 fulcrummed on a bracket 38 attached to the casing 10. The lever is maintained in contact with the bar 31 by means of a spring and as it comes into contact with the cranked portion of the bar the damper is moved into contact with the cones 13. In use the appliance is held so that the rotating brush acts upon the teeth. According to the Provisional Specification the main spindle is rotated by a flexible drive and is provided at one end with a socket member having a tapering cavity which engages a cone piece provided on the brush spindle. The main spindle is also provided with oppositely tapering conical members and a driving cone has its spindle mounted in a slide piece carried by the body wall so that on moving the slide piece the driving cone may engage one or other of the conical members. A flexible drive cable is connected to the slide piece, the rotary core of the cable being coupled to the spindle of the driving cone.