Patent GB-190219087-A (GB)
Title: Improvements in Speed Gear.
Inventor: BARBER THOMAS WALTER
Filed: 1902-08-30
Granted: 1903-11-30
Abstract: 19,087. Barber, T. W. Aug. 30. Eccentrics.-Relates to variable-speed and reversing gearing suitable for motor vehicles, winches, &c. The gearing is carried by a frame A', secured to a main frame A, and is supported by the driving and driven shafts B, C. A flanged disc B<1> is secured to the frame A', and a similar disc C<1> engages a groove in this frame and is free to rotate on the shaft C. These discs act as a casing for the gearing. A sleeve B<3> is mounted to slide on a key on the shaft B, and is moved by any suitable means such as the lever L and screw L<4>. The end of the sleeve projects through a slot D' in an adjustable eccentric D, and acts as a support for the end of the shaft C. The eccentric is connected by links B<5> to the sleeve B<3> so that, by moving the sleeve, the throw of the eccentric can be adjusted. A strap E surrounds the eccentric and is provided with sets of lugs or ears E' in which are provided arms F, G. Each of the arms F carries a spring- controlled pawl F<1> provided with a pin F<3> taking into a slipper F<4> arranged in a groove C<4> in the disc C<1>. A second pin on the pawl may engage a recess in the frame A'. According to a modification, the member C<1> is made in two parts in each of which slides a shoe receiving one of the eccentric pins of the pawl, which may be grooved to engage the grooved periphery of the member C<1>. In another arrangement, a spindle provided with right and left handed threads engages slippers, working in grooves in the member C', and is coupled to the arm F by a link. The strap E may be prevented from rotation, by supporting it on a plate, so that it is free to slide in a vertical direction, the plate being capable of a horizontal movement on the face of the member B'. Preferably the strap is free to rotate, in which case the arms G are provided with spring-controlled pawls G<1 >coupled to shoes sliding in a groove in the disc B', as in the case of the pawls &c. coupled to the arms F. In operation, supposing the strap E to be prevented from rotating, the eccentric D moves the strap so that the pawls &c. on the arms F are moved to and fro in the groove in the member C<1> and drive the member in the direction in which they grip. If the strap E is free, the arms G and pawls &c. cause it to rotate so that double the amount of movement given to the arms F is imparted to the member C<1>. To vary the speed of the member C', the throw of the eccentric D is adjusted by moving the sleeve B<3>; when the eccentric is brought concentric with the shaft B no movement is transmitted from the shaft B to the member C<1>. Other suitable devices may be employed for varying the throw of the eccentric. The motion of the member C<1> is transmitted to the shaft C through gearing so arranged that a reversal of the direction of running may be obtained. An internally-toothed ring H fixed to the member engages pinions H<1> in gear with a wheel H', the pinions and wheel being mounted in bearings in a bracket A' on the frame A. A split ring J is arranged between the boss H<3> of the wheel H<2 >and a sleeve C<6> on the member C'. The ring is connected to an arm C<7> fast on a sleeve C<8> keyed to the shaft C. A spindle provided with right and left handed threads engages lugs on the ring J, and carries a pinion K<3> in gear with a rack K<2> on a sleeve K<1> free to slide on the shaft C. This sleeve may be moved by means of the screw M<2>, lever M', &c., and serves to open or close the split ring J so as to bring it into driving contact either with the boss H<3> or the sleeve C<6>. When the ring J grips the sleeve C<6>, the shaft C is driven directly by the member C<1>, but, when the ring grips the boss H<3>, the shaft is driven, through the toothed gearing, in a direction opposed to the direction of rotation of the member C<1>. Several sets of engaging-devices may be arranged in connection with the members B<1>, C' and may engage the peripheries of discs or of teeth formed upon the members. In place of transmitting power through the shaft C, one or both the members B<1>, C<1> may be formed as belt pulleys or toothed wheels. Both members B', C' may be adapted to rotate so as to act as a differential gear.