Patent GB-497347-A (GB)
Title: Improvements in or relating to apparatus for producing reciprocating movement from rotary movement
IPC: G05D13/10
Filed: 1937-06-17
Abstract: 497,347. Snap-action switches. REYROLLE & CO., Ltd., A., and WILLIAMS, T. June 17, 1937, No. 16827. [Class 38 (v)] [Also in Group XXIV] Apparatus for producing a continuous reciprocating movement from a rotary member, comprises a centrifugal governor driven by the rotary member and means for automatically causing a continual change in the governor speed back and forth between a maximum and a minimum so as to cause continual reciprocation of the axially movable member of the governor. As applied to apparatus for charging a spring for closing an automatic circuit breaker by means of a hydraulic jack, the device comprises a casing A to the lower part of which is secured an electric motor B with a vertical shaft B<1> the upper end of which is coupled to the lower end of a governor shaft C carried in bearings C<1>, C<2>, and having its upper end bored. Governor links D, D<1> pivotally connected at D<2> have their lower ends connected to the governor shaft at C<3>, the upper being pivoted to lugs D<3> on a sleeve D4 arranged to slide in the bore of the shaft C. The governor weights are not shown. Pivotally supported in lugs A<1> is a shaft E carrying a lever having spaced arms E<1> between which supported in trunnions E<2> is a housing E<3> Fig. 1, containing a thrust bearing F through which it is connected to a rod F<1> passing through the sleeve D<4> and having a head F<2> to bear on the lower end of the sleeve. A tie G, Fig. 2, between the arms E<1> has a laterally extending pin G<1> which is connected to the upper end of a guide rod G<2> surrounded by a spring G<4> bearing on a lug G<3> and therefore always tending to move the lever E<1> upwards. If the speed of the motor B is continually varied, the sleeve D<4> will be moved downwardly on an increase of speed and upwardly by the spring G<4> on a decrease of speed, thus causing the lever E<1> to oscillate. This oscillating movement is utilized to actuate a switch to control the speed of the motor. Thus, a rod H passing through a lug E<4> on the lever E<1> has two adjustable stops H<1>, H<2> and is pivoted to one end of a lever J, Fig. 2, supported on a pivot J between the casing A and a plate J<2> spaced from the casing and mounted on three studs J<3> ... J5. A second lever, K, also mounted on the pivot J<1> carries a pin K<3> and is loaded by a spring K<1>. Pivoted to the lever J is a catch lever L with upper curved portion L<1>, and a lower part acted on by a spring M and provided with a lug L<2> adapted to engage a part of lever K. The extreme end portion L<4> of lever L is adapted to actuate the movable part N of a switch N<1> having contacts N<2> ... N4. Also pivoted to lever J is a curved bar O adapted to be acted on by the pin K<3> and to actuate the member N in the other direction. The parts are shown in Fig. 2 in the position which they occupy when the member N has been moved to the right owing to the governor having reached its minimum speed. As the motor and governor speed increases, the rod H is moved downwards rocking the levers J, K clockwise until the curved part L<1> engages a roller J<6>, Fig. 3, on stud J4, whereupon lever L is rocked and the lug L<2> releases the lever K. This lever then turns anticlockwise with a snap-action and the pin K<3> acts on the bar O to cause it to move the part N to the left, Fig. 3. The current to the motor is then either cut off or varied so as to tend to reverse the motor which then slows down. The spring G4 forces the lever E<1> and with it the rod H upwards to move the lever J anticlockwise carrying with it the lever L and bar O. The lever K during this movement is permitted to return to the position shown in Fig. 2, after the surface L<1> has left the roller J<6>. As the levers J, K reach the position shown in Fig. 2, the lug L<2> passes beyond the lower edge of the adjacent end of the lever K and is drawn with a snap-action by spring M to the position in Fig. 2. During the snap-action, the end L4 of lever L moves the switch member N to the right to increase the speed of the motor. A further tie-member with projecting end P may actuate the piston P<2>, Fig. 1, of a pump P<3> for delivering fluid to a hydraulic jack for charging the spring. The shaft E may carry a further lever E<5> by which an additional member may be actuated.