US2039186A - Hydraulic servomotor for train controllers and the like - Google Patents

Description

April 28, 1936. I PIEPER H 2,039,186

HYDRAULIC SERVOMOTOR FOR TRAIN CONTROLLERS ANO .THE LIKE Filed 001-. 21, 1953 Patented Apr. 28, 1936 PATENT OFFICE HYDRAULIC SERVOMOTOR FOR TRAIN CONTROLLERS AND THE LIKE :Henri Pieper, Brussels, Belgium Application October 21, 1933, Serial No. 694,676

In Germany October 22, 1932 6 Claims.

My invention relates to a motor driving device for controllers 'of electric power vehicles in multiple unit trains, for vehicle doors or similar apparatus to be adjusted at difierent points of a circular, rectilinear or other path of motion, in which apparatus a piston serving to drive this apparatus is moved by a pressure liquid and can be connected, by means of distributing members, at both sides to a charge-reservoir or a discharge reservoir respectively.

According to my invention this driving and controlling device is simplified in its construction and improved'in its mode of operation by that an electromagnet effects the stopping of the driving piston and of the apparatus to be adjusted in the desired position without the aid of a special valve inserted otherwise in the circuit of the liquid. For this purpose, according to my invention, this electromagnet which is excited after the starting of the apparatus to .be adjusted, effects at the desired instant through the instrumentality of the engagement of a detent in a grooved disc the stopping of the driving piston and thereby also the arresting of the pressure liquid. There is thus efiected with simple means a sudden shifting of the apparatus to be adjusted from one position to another and an accurate arrest of the driving piston at the desired point of the path of motion. The excitation of this electromagnet takes place after the starting of the apparatus to be adjusted preferably at the instant at which the detent resting on the periphery of the grooved disc sets about to enter into the groove which corresponds with the desired position and the electromagnet remains excited until the driving piston is started again, before which start it is switched ofi for an instant.

The drawing shows in Fig. 1 by way of example one embodiment of my invention as applied to a driving device to adjust a controller for an electric power car. Figs. 2 and 3 show the rotating contact drum of the arrangement of Fig. 1 in two positions-differing from the position shown in Fig. 1.

The driving device comprises a driving liquid, for example, oil and a charge reservoir 2 containing compressed gas,-for example, compressed air, a discharge reservoir 4 which is open to the atmosphere and a hydraulic rotary piston motor, which consists of an annular cylinder 3a. and an oscillating blade-like piston 3. The two spatially variable compartments 3a and 3a", which are formed in the cylinder 3a by means of the bladepiston 3, can be placed in communication alternately with the charge reservoir 2 or the dis charge reservoir 4 by means of a distributing cock 5, which is adjusted by means of an electromagnet 5k in opposition to the action of a spring 51'. When the electromagnet 5k is not excited, the spring 51' holds the cock 5 in the position repre- 5 sented in full lines in the drawing, in which the cylinder compartment 3a is connected with the pressure reservoir 2 through the ducts 6, I and the port 5' in the cock, while the cylinder compartment 3a" is connected to the discharge reservoir 4 by way of the ducts 8, 9 and the ort 5" in the cock. When the electromagnet 5k is excited, it rotates the cock 5 into the position indicated in dotted lines in the drawing, in which the cylinder compartment 3a is connected withthe discharge reservoir 4 and the cylinder compartment 3a" with the charge reservoir 2. By turning the cock 5 into the one or the other of these two positions the rotation of the bladepiston 3 in the clockwise direction or in the opposite direction of rotation is in this manner effected by the driving liquid.

The shaft ll of the rotary piston 3 carries a disc l3 provided with grooves l3a and a latchshaped detent l3b is drawn against the periphery of the disc B by means of a spring I31 and also by means of an electromagnet l2k when the latter is excited. The electromagnet HR: is designed to be powerful enough to arrest the motion of the rotary piston 3 and so to stop said piston and the apparatus which is to be adjusted, when the electromagnet coil [2k is switched in and holds the detent I3b in firm engagement with a groove l3a of the disc l3. The spring I31 alone is unable to stop the piston 3. The duct I contains a valve Ia which opens according to the cock 5 and is held closed by means of an electromagnet 1k, when the latter is excited. A damper Id, the piston of which moves in a liquid and is provided with small openings, permits the valve la to be opened quickly by switching off the electromagnet ilc but retards the closing movement of this valve when the electromagnet 1k is excited. The duct 8 possesses a valve 8a which rests on a set-screw 8d under the action of its weight or of a spring, which set-screw is so set that the valve 8a ofiers a small opening for the liquid in the direction of flow towards the cylinder 3a and a large opening in the opposite direction of flow.

The electromagnets 1k and I210 are controlled by means of a drum H), which is coupled with the piston shaft I4 and is provided with contactpieces Ilia, lflb', llic', Hid, and Hie. The drum Hi can be set in different positions, for example, in four different positions relatively to the fixed contacts lOa, lOb. I00, Id and Hie. The circuits of the electromagnets 1k and HR: also pass through the segments of a hand change-over switch. H, which is connected with the battery l8 or another source of electric energy. The electromagnet 5k, which controls the cock 5, is connected directly to one oi! the segments of the change-over switch H. The hand-lever oi the change-over switch I! can occupy four positions corresponding to the four positions of the drum l0. When it is a matter of driving a controller 20 for electric motors, the position 0 of the change-over switch I! corresponds to the zero position of the controller, the position P. S to the connection of the electric motors in series with resistances switched in, the position S to the connection in series without resistances and the position P to the connection of the electric motors in parallel, while the return of the controller into the zero position can take place in one movement without intermediate positions. In

order to block the driving device if the current of the electric motors exceeds a definite amount, a relay which is traversed by said current is provided, which closes a keeper Ila when the current strength reaches the determined amount. The switch Ha of the relay ll then connects the electromagnet l2]: directly with the battery l8 and this electromagnet effects the stopping of the motor 3 and consequently also that of the controller of the electric motors, until the motor current resumes its ordinary value.

The driving device works as followsz-When the hand-switch l1 occupies the position 0 the drum I0 is also in the position 0 shown in Fig. l and the electromagnet 1k is excited by way oi! the contact-piece Illa in the drum in and keeps the valve la closed, while the electromagnets 5k and I 2k are switched off. The closedvalve 1a prevents the pressure in the reservoir 2 from acting on the liquid in the cylinder 3a, so that in the latter no losses of liquid can occur through liquid passing over from one side of the blade-piston 2 to the other. It the hand switch I! is moved into the position P. S the electromagnet 1k is switched off so that the valve 1a can open and at the same time the electromagnet 5k is switched in, which electromagnet then moves over the cock 5 into the position drawn in dotted lines, in which position the cylinder compartment 3a is connected to the discharge reservoir 4 and the cylinder compartment 3a" to the charge reservoir 2. The piston 3 and the drum I0 are consequently set in rotation in the direction of the arrow l5 by means of the driving liquid. As soon as the drum III has reached the position P. S shown in Fig. 2 it closes the circuit of the electromagnet [2k at the contact-piece Hlb', which at this instant bridges over the fixed contacts lfla and I 0b. The excited electromagnet I27: presses the detent l3b into the groove l3a of the disc l3 which corresponds to the position P. S. and so arrests instantaneously the' piston 3 and the driving liquid in this position. The excitation of the electromagnet l2k commences at the instant at which the detent [322 sets about to fall into the groove l3a corresponding to the position P. S.

When the hand-switch I1 is brought from the position P. S into the position S, there takes place another switching ofi of the electromagnet l2k, so that the driving liquid can again set in rotation the rotary piston 3 and the drum l0 and also the apparatus to be adjusted. As soon as the drum l0 reaches the position S shown in Figure 3, its contact-pieces I00 and we close the circuits of the electromagnets l2k and Us. The electromagnet I 2k again stops the piston 3 and the drum III, while the closure of the valve Ia produced by means of the excited electromagnet 1k is accomplished slowly owing to the retarding action of the damper Id. It the hand-switch I7 is brought from the position 8 into the position P the circuits of the electromagnets 1k and 12k are again broken by the hand switch I! before it reaches the position P, which permits the restarting of the piston 8 and or the drum ID by means of the driving liquid because the deenergized electromagnet 1k allows the valve la to be opened by the pressure oi. the reservoir 2, whilst the deenergized electromagnet I2k allows the piston I to be driven by the pressure liquid coming from the reservoir 2 through the valve 1a and the pipes I and 8. The drum l0 maintains the break in the circuit of the electromagnet 1k during its passage from the position S to the position P whilst it on its; arrival in the position P closes by means of its contact piece we again the circuit of the electromagnet lk, which on the other hand is completed by the hand switch l1 occupying at this instant the position P. The excited electromagnet 1k arrests the motion of the driving liquid by closing the valve la, while the piston 3, which has now reached the end of its stroke can be stopped in the position P simply by means of a stop on the cylinder 30. so that a further excitation of the electromagnet l2k is not necessary.

The electromagnet 51: remains excited in the three positions P. S, S and P of the hand-switch H and during the whole of this time holds the cock 5 in the position indicated by dotted lines, in which it connects the cylinder compartment 30:" with the pressure reservoir 2. Since the valve 8a has a passage of small cross-section for the driving liquid in the direction of flow towards the cylinder compartment Be, the movement of the piston 3 and consequently of the apparatus to be adjusted can take place in the direction of the arrow l5 at only a moderate velocity. In order to. return the apparatus to be adjusted into the zero position, the hand-lever I1 is brought back into the position 0 in one movement without intermediate positions. On the arrival of the hand-lever H in the position I] the circuit of the electro-magnet 5k is interrupted, so that the spring 51' can shift the cock into the position indicated in full lines, in which the pressure-reservoir 2 is connected with the cylinder-compartment 3a and the discharge reservoir 4 with the cylinder-compartment 3a On the other hand during the return of the hand-switch I! from the position P into the position ll the electromagnet 1k is switched oif for a definite time which is sufficient to allow the valve la to open in consequence of the non-excitation of the electromagnet 1k. Since the closure of the valve la on the electromagnet 1k being switched in again in the position 0 of the handswitch I? can be accomplished only slowly in consequence of the retarding action of the damper 1d the driving liquid has sufiicient time to return in the direction of the arrow 19 into the zero position the piston 3 and the drum l0 and also the apparatus to be adjusted before the valve la is completely closed again. The quick return into the zero position is facilitated by the valve 8a, which presents a passage with a large cross-section to the liquid flowing away from the cylinder compartment 3a" towards the discharge reservoir 4.

The arrest of the piston 3 in the zero position, in which the electromagnet We is not excited, can be eii'ected by means of a stop on the cylinder in, since the piston in this position is at the other end of its stroke.

My invention may also of course be carried out in details in a manner deviating from the example illustrated, a motor with a reciprocating'piston being for example employed instead of the rotary piston motor shown in the drawing.

Having now described the nature of my invention I declare what I claim is:--

1. A hydraulic servo-motor for driving an element step by step and looking it in any desired step, comprising in combination a charging reservoir containing liquid under pressure, a cylinder, 9. piston in this cylinder for driving the apparatus to be adjusted, a discharging reservoir, distributing means for connecting said cylinder on both its ends alternately to said charging reservoir and to said discharging reservoir, means for controlling electrically said distributing means, a disc driven by said piston and having grooves corresponding in number and position to the individual positions of arrest of the apparatus to be adjusted, a pawl-like organ resting on said grooved disc and capable of engaging in the grooves of said disc, an electromagnet capable of acting when excited upon said pawl-like organ so as to bring it into engagement with one of the grooves of said grooved disc and thereby to arrest the driving piston and the pressure liquid, and means for exciting said electromagnet after the starting of the apparatus to be adjusted.

2. A hydraulic servo-motor for driving an element step by step and looking it in any desired step, comprising in combination a charging reservoir containing liquid under pressure, a cylinder, a piston in this cylinder for driving the apparatus to be adjusted, a discharging reservoir, distributing means for connecting said cylinder on both its ends alternately to said charging reservoir and to said discharging reservoir, means for controlling electrically said distributing means, a disc driven'by said piston and having grooves corresponding in number and position to the individual positions of arrest of the apparatus to be adjusted, a pawl-like organ resting on said grooved disc and capable of engaging in the grooves of said disc, an electromagnet capable of acting when excited upon said pawl-like organ so as to bring it into engagement with one of the grooves of said grooved disc and thereby to arrest the driving piston and the pressure liquid, and controlling means driven by said piston for exciting said electromagnet at the instant at which the pawl-like organ moves to enter into the groove of said disc corresponding to the desired position and for maintaining this excitation until said driving piston is started again and manual means for switching of! this excitation for a certain time when said piston is to be started again.

3. A hydraulic servo-motor for driving an element step by step and looking it in any desired step, comprising in combination a charging reservoir containing liquid under pressure, a cylinder, a piston in this cylinder for driving the apparatus to be adjusted, a discharging reservoir, distributing means for connecting said cylinder on both its ends alternately to said charging reservoir and to said discharging reservoir, means for controlling electrically said distributing means, a disc driven by said piston and having grooves corresponding in number and position to the individual positions of arrest or the apparatus to be adjusted, a pawllike organ resting on said grooved disc and capable or engaging in the grooves of said disc, an electromagnet capable of acting when excited upon said pawl-like organ so as to bring it into engagement with one of the grooves of said grooved disc and thereby to arrest the driving piston and the pressure liquid, and controlling means driven by said piston for exciting said electromagnet at the instant at which the pawl-like organ moves to enter intothe groove of said disc corresponding to the desired position and for maintaining this excitation until said driving piston is started again and manual means for switching off this excitation for a certain time when said piston is to be started again, a valve inserted between the cylinder of said driving piston and said charging reservoir and means for electrically controlling said valve so as to shut off the supply of liquid to said cylinder in all positions in which the apparatus to be adjusted remains stopped during a certain time. i

4. A hydraulic servo-motor for driving an element step by step and looking it in any desired step, comprising in combination a charging reservoir containing liquid under pressure, a cylinder, a piston in this cylinder for driving the apparatus to be adjusted, a discharging reservoir, distributing means for connecting said cylinder on both its ends alternately'to said charging reservoir and to said discharging reservoir, means for controlling electrically said distributing means, adisc driven by said piston and having grooves corresponding in number and position to the individual positions of arrest of the apparatus to be adjusted, a pawl-like organ resting on said grooved disc and capable of engaging in the grooves of said disc, an electromagnet capable of acting when excited upon said pawl-like organ so as to bring it into engagement with one of the grooves of said grooved disc and thereby to arrest the driving piston and the pressure liquid, and controlling means driven by said piston for exciting said electromagnet at the instant at which the pawl-like organ moves to enter into the groove of said disc corresponding to the desired position and for maintaining this excitation until said driving piston is started again and manual means for switching off this excitation for a certain time when said piston is to be started again, a valve inserted between said cylinder of said driving piston and said charging reservoir, an electromagnet capable of acting when excited upon said valve so as to close it, a damper connected to the armature of said electromagnet so as to retard its closing action and means for electrically controlling said electromagnet.

5. A hydraulic servo-motor for driving an element step by step and looking it in any desired step, comprising in combination a charging reservoir containing liquid under pressure, a cylinder, a piston in this cylinder for driving the apparatus to be adjusted, a discharging reservoir, distributing means for connecting said cylinder on both its ends alternately to said charging reservoir and to said discharging reservoir, means for controlling electrically said distributing means, a disc driven by said piston and having grooves corresponding in number and position to the individual positions of arrest of the apparatus to be adjusted, a pawl-like organ resting on said grooved disc and capable of engaging in the grooves of said disc, an electromagnet capable of acting when excited upon said pawl-like organ so as to bring it into engagement with one of the grooves of said grooved disc and thereby v to arrest the driving piston and the pressure liquid, and controlling means driven by said piston for exciting said electromagnet at the instant at which the pawl-like organ moves to enter into the groove 01' said disc corresponding to the desired position and for maintaining this excitation until said driving piston is started again and manual means for switching of! this excitation for a certain. time when said piston is to be started again, a valve arranged between said cylinder of said driving piston and said distributing means and presenting a passage of contracted crosssection to the liquid flowing towards said driving piston and a passage of large cross-section to the liquid flowing in the opposite direction.

6. A hydraulic servo-motor for driving an element step by step and looking it in any desired step, comprising in combination a charging reservoir containing liquid under pressure, a cylinder, a piston in this cylinder for driving the apparatus to be adjusted, a discharging reservoir, distributing means for connecting said cylinder on. both its ends alternately to said charging reservoir and to said discharging reservoir. means for controlling electrically said distributing means, a disc driven by said piston and having grooves corresponding in number and position to the individual pomtions of arrest of the apparatus to be adjusted, a pawl-like or an resting on said grooved disc and capable of e aging in the grooves of .said disc, an electromagnet capable' of acting when excited upon said pawl-like organ so as to bring it into engagement with one of the grooves of said grooved disc and thereby to arrest the driving piston and the pressure liquid, and controlling means driven by said piston for exciting said electromagnet at the instant at which the pawl-like organ' moves to enter into the groove of said disc corresponding to the desired position and for maintaining this excitation until said driving piston is started again and manual means for switching 01! this excitation for a certain time when said piston is to be started again, said driving piston and its cylinder being formed as a rotary piston motor.

- HENRI PIEPER.

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