US1899683A - Electrically driven vehicle - Google Patents

Description

Feb. 28, 1933. s 5 GUY ET AL 1,899,683

ELECTRICALLY DRIVEN VEHICLE Filed May 29, 1950 2 SheetsSheet l POWER PEDAL.

OFF START RUN- 2626 O O 20 g 22 OFF 7 FW\D REV 32 6 1 POWER PEDAL 4 'T1 1 7' MorCr 2 INVENTORS' Feb. 28, 1933. 5 5 GUY ET AL 1,899,683

ELECTRICALLY DRIVEN VEHICLE Filed May 29, 1950 2 Sheets-Sheet 2 y INVE NTO RS Patented Feb. 28, 1933 PATENT OFFICE SYDNEY SLATER GUY, OF WOLVERHAMPTON, AND WILLIAM ARTHUR STEVENS, OI

MAIDSTONE, ENGLAND ELECTRICALLY DRIVEN VEHICLE Application filed May This invention relates to electrically driven vehicles, equipped with dynamo-electric machines which are capable of regeneration, and has for its object to provide means whereby,

in the event of the driver removing his foot from the power pedal, the circuits will automatically close and remain closed during the whole time the machine continues to act as a generator and will automatically open when the machine, by reason of its reduced speed, ceases to generate at a higher voltage than that of the line. Alternatively, means may be provided whereby the circuits can automatically be broken immediately the hand brake, foot brake or reverse lever is employed so that it will be impossible for the driver toapply power and braking at the same time, or to put the vehicle in reverse whilst the circuits are closed.

In the acconnpauying drawings,

Figure 1 illustrates, diagrammatically, one method of arresting the controller drum in the regenerative position.

Figure 2 illustrates another method by which the controller drum can be electrically arrested in the regenerative position.

Figure 3 shows an alternative form of magnetic pawl.

Figure 4 illustrates diagrammatically another method of pedal control.

Referring to the drawings, 1 is the arma ture of a compound wound dynamo-electric machine, the series and shunt field windings 2, 3 of which have variable resistances 4 and 5 which are connected in series therewith respectively and are controlled by a starting and speed changing resistance controller 22 operated by a power pedal A. The circuit is completed through contactors 16-16 which are respectively connected with stationary contacts 2O20 in well known manner.

In the arrangement shown in Figure 1 the controller drum 22 is arrested at the position of maximum regeneration, when the driver takes his foot ofl the power pedal, by means of a magnetically operated pawl 26 which may take the form of a polarized armature pivoted at 26 and is adapted to engage behind the shoulder 25 of a cam or segmental 29, 1930, Serial No. 457,304, and in Great Britain July 19, 1929.

catch plate 25 fixed to the shaft of the controller drum. The pole pieces of the magnet 28 are energized by means of a winding 28,

in series with the main circuit, the current through which is reversible, whilst the winds ing 26 of the polarized armature 26 is connected in series with the shunt field winding 3, the current through which is unidirectional.

The arrangement is such that,'when the machine is acting as a motor and the current is flowing in one direction through the magnet winding 28 the pivoted pawl 26 is heldin its inoperative position by the attraction of the pole 28 of the magnet 28, but when the machine commences to act as agenerator' and the direction of flow of current through the magnet winding 28 is reversed, the pivoted pawl is attracted by the pole 28 into the position shown in Figure 1 in which it engages the shoulder 25 on. the cam 25 to hold the controllerdrum in the position of maximum regeneration. When the speed of the vehicle'drops below that required to sustain regeneration the current through the mag net winding 28 is insufiicient to hold the pawl 26 in its operative position and the con-. troller drum, being thereby released, is re-- turned to the zero position by the action of the spring of B the power pedal. The shoulder 25 on the cam is preferably inclined awa from the radial in order to facilitate the release of the pawl.

Figure 2 shows another arrangement for retaining the controller drum 22 in the middle or regenerative position when the driver takes his foot oil the power pedal. In this case the winding 28 which is excited by two windings 29 The heavy winding 29 is connected with the main circuit in which the of the electro-magnet 28 is of high resistance and connected across and 7 by means of a polar of current varies accordingly as the ternatively, be a high resistance coil in circuit between trolley poles 6 and 7, this circuit being preferably broken by the action of the governing control drum 22, as shown in Fig. 3, so that the high resistance coil is not excited when current is cut off from the dynamo-electric machine.

A reverse current relay having an armature carrying a switch 30 is adapted to move to cause switch 30 to complete the circuit from circuit 18 through the contacts 30 to one side of the winding 28 oft'he electro-magnet 28. When in consequence of the power pedal beingreleased, the dynamo-elec- V oted pawl 26 to be released from engagement with the cam 25 by means of a spring26 whereupon the controller drum is free to return to the back or off position under the influence of the power pedal spring B.

Figure 3 shows an alternative method of arresting the controller drum 22 in the middle' or regenerative position. In this case the vertical rod 31 which connects the power pedal with the controller drum is provided with a collar 31 which is adapted to be engaged by a trip lever 33 pivoted on the armature 33 of an electro magnet 34. The winding 35 of this magnet is connected and excited .in the sameway as shown in Figure 2. When the-controller drum 22 is being pushed forward for driving purposes and the rod 31 is moved upwardly by the forward action of the power pedal, the trip lever 33 will lift and allow the collar 31 to pass. When, however, the dynamo-electric machine is regenerating and the electro magnet 34 is consequently excited, the trip lever 33 will prevent the rod 31' and hence the controller drum 22 retu-rningbeyond' the point at which regeneration is atits maximum. l/Vhen regeneration' ceasesjthe electro magnet 34 will lose its excitation and the armature 33 and trip lever 133, being thereby released, will be free to take up. a position, such as that indicated in dotted lines, so that the collar can pass and the controller drum return to the neutral oroif" position.

The operation of the magnetically operatedpawl 26 of Fig. 2 or trip lever 33 of Fig; 3, in releasing'the controller drum, insteadof being controlled by the effect of electrical regeneration, may be made to deq pendupon the driver moving a control, such 65 as, for lnstance the foot brake, in which case position the magnetcircuit may include a switch 35 adapted to be opened on the operation of said foot brake.

In all the above arrangements the power pedal may be so connected that it moves with the drum in both directions and is consequently held in an intermediate position when the controller drum is retained in the regenerative position by the aforesaid pawl or trip lever.

The necessity for the use of a magnetically operated device for the purpose of. arresting the controller drum 22 in the regenerative position can, however, be dispensed with and the pawl or its equivalent arranged to be mechanically released by the operation of a movable part, such as, for instance, a hand brake lever.

An arrangement for this purpose is shown in Figure 4. A catch piece 40 having a hook 40 and a short arm 40 and being pivotally mounted at one side of the cam 44 is adapted to engage behind shoulder 41 of the quadrant 42 on a lever or arm A which is connected with the controller drum 22 and urged toward raised position by spring B. The

cam 44 is pivotally mounted at 45 and connected by a link 46 with brake lever 47 so that as the latter is moved the cam 44 will be turned about the pivot 45. Turning movement of the cam 44 in one direction causes it to engage and raise the short arm 40", so depressing the long arm and hook 40 against the pull of spring 40, thus releasing the quadrant 42-. Of course rotary movement of the cam 44 in the reverse direction displaces it away from. the arm 40" so that the spring 40 may move the long arm with its spring 41 upward asthe quadrant 42 is moved to the point where its shoulder 41 lies to the rear of the hook 40 and may hold the hook 40 in raisedengaging until the cam 44 is rotated in the reverse direction. The power pedal 24 is mounted on the same axis as the lever 43 aforesaid, which is connected with the control drum, and rotates the latter in the forward direction by means of a shoulder 22*, between which and a correspondingshoulder 43 on the boss of said lever there is a clearance of about 15. The operation of this mechanism is as followsz-Normally, the

catch piece 40 lies below the quadrant-faced.

projection 42 on the lever 43 operating the control drum. When the driver depresses the power pedal, the lever 43 is rotated to turn the control drum, the quadrantrfaced projection 42 on said lever riding over the catch piece 40 until the regenerative position is passed, when the catch piece, by means of a spring 40*, the quadrant-faced projection. If now the driver takes his foot ofi' the power pedal, the lever 43, and consequently the controller drum. is arrested at the regenerative posisnaps into position behind tion by the catch piece 40, in which position it will remain until the driver operates either the hand brake, foot brake or reverse lever, in either of which cases the said catch piece will be moved against its spring 40 out of engagement behind the quadrant-faced projection, whereupon the control drum will return to the off position.

In each of the above described arrangements the circuits of the dynamo-electric machine, when the driver takes his foot off the power pedal, are kept closed by arresting the return movement of the controller drum at the position of maximum regeneration, in which both the series and shunt resistances are short-circuited.

We claim:

1. In a system for an electrically driven vehicle, a dynamo-electric machine, controlling means therefor including a controller device having a neutral position and a plurality of operating positions, means operable for actuating said device to one of said operating positions, means for returning said device to the neutral position after an operation of said first-named means and means responsive to the change of direction of the current flow for retaining said device in one of said operating positions.

2. In a system for an electrically driven vehicle, a source of electrical energy, a dynamo-electric machine for driving said vehicle, controlling means for associating said machine with said source including a controller having a neutral position and a plurality of operating positions, means operable for actuating said controller to said operating positions, and means effective only while power is being delivered by said machine to said source for preventing said controller from being returned to the neutral position, after an operation of said second-named means.

3. In a system for an electrically driven vehicle, a source of electrical energy, a dynamoelectric machine for driving said vehicle, controlling means for associating said machine with said source including a controller having a neutral position and a plurality of operating positions, means operable for actuating said controller to any of said operating positions, and means effective after an operation of said second-named means for actuating said controller to the position roviding the maximum return of energy by said machine to said source and for maintaining said controller in said last-named position while energy is being returned by said machine to the source, said last-named means returning the controller to the neutral position after said machine ceases to deliver energy to said source.

4. In a system for an electrically driven vehicle, a source of electrical energy, a dynamo-electric machine for driving said vehicle, controlling means for associating said machine with said source including a controller having a neutral position and a plurality of operating positions, means operable in either of two directions along a predetermined path for actuating said controller to said positions, and means for preventing the operation of said second-named means in only one of said directions, said last-named means being effective only while said machine returns power to the'source.

5. In a system for an electrically driven vehicle, a source of electrical energy, a dynamo-electric machine for driving said vehicle, said machine having an armature, controlling means for associating said machine with said source including a controller movable into a plurality of operating positions, a stop member associated with said controller and movable therewith, magnetic means movable into or out of engagement with said member for restricting movement thereof, and means for energizing said second-named means in accordance with the direction of flow of current in the armature of said machine, whereby a current flow in one direction causes said second-named means-to engage the member for defining a predetermined limit of movement for said controller, and current flow in the opposite direction causes the secondnamed means to withdraw from engagement with said member.

6. In a system for an electrically-driven vehicle, a source of electrical ener y, a dynamo electric machine for driving said vehicle, controlling means for associating said machine with said source including acontroller movable along a predetermined path into a plurality of operating positions, a stop member associated with said controller and movable therewith, and magnetic means cooperating with said member comprising a magnetic structure, an armature body pivotally related to said structure, an element pivotally affixed to said body and adapted to engage said member, said element pivoting with reference to the body for permitting the member to pass in only one direction of travel, said body pivoting with reference to the structure for permitting the member to pass the element in the opposite direction of travel, and means for energizing the structure in accordance with the direction of flow of current in the armature of said machine, for preventing said body from pivoting with reference to the structure when the current flows in a predetermined direction said energization permitting the body to pivot when the current flows in the opposite direction.

7. In a system for an electrically-driven vehicle, a source of electrical energy, a dynamo-electric machine for driving said vehicle, controlling means for associating the machine with the source including a controller movable to a neutral position and a plurality of operating positions, means operable for actuatingsaid controllerto one of said operating positions, biasing means for returningsaidcontroller to the neutral positionafter an; A operation of said second-named means, a-stop member aflixed to said controller and movable therewith, and a magnetic device associated with said member comprising a magneticstructure, an armature element for said structure movable into or outrof engagement with said member, an electrical-winding for said structure, an electrical windingfor said element, one of said'windings beingenergized from an electrical source of energy of constant polarity, the other winding being 7 adapted to carry a current varying in direction of flow with the current in the armature 013 said machine, whereby when the current inthe armature of said machine flows in a predetermined direction, in excess of a pre? determined magnitude, the element is moved into engagement with the member for preventing return of the controller to the neutral position after an operation of said second named means, and When the armature current flows in the opposite direction, said element is Withdrawn from engagement With said member.

SYDNEY SLATER GUY. g6 WILLIAM ARTHUR STEVENS.

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