US1277408A - Control apparatus. - Google Patents

Description

A. J. HALL.

comm APPARATUS. APPLICATION FILED AUG-4.15MB.

1,9? M080 Patented mm, 1918.

Trolley.

i A F a bed INVENTOR Ak'fhur J Hall.

u i a m ARTHUR J. HALL, :OF WILKINSBURG, PENNSYLVANIA. ASSIGNOR TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, .A. CORPORATION OF PENNSYLVANIA.

CONTROL APPARATUS.

Speeificationof Letters Patent.

Patented Sept. 3, 1918.

To all whom it may concern:

Be it known that I, ARTHUR J. HALL, a subject of the King of Great Britain, and a resident of lVilki-nsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Control Apparatus, of which the following is a specification.

My invention relates to control apparatus and especially to electrically-controlled, fluid-pressure actuated controlling devices for governing motor-circuit connections or the like. I

In the prior art it has been proposed to provide mechanisms of the general type to which my invention appertains wherein compressed air, or other fluid under pressure, has been employed to overcome .the resist ance of atmospheric pressure and thereby effect the desired movements of the device. Such an apparatus is set forth and claimed in a patent to N. 7. Storer and A. J. Hall, Number 1,229,5i3, dated June 12, 1917, and assigned to the Westinghouse Electric & liianufacturing Company.

The object of my present invention is to provide an operating mechanism ;of the class under consideration wherein, preferably, atmospheric pressure is utilized as the motive power to operate against a predetermined degree of vacuum to effect results similar .to those heretofore obtained by the previously mentioned hi gh-fl-uid-press-ure apparatus.

My invention may best be understood reference to the accompanying drawing, wherein Figure 1 is a diagrammatic view of system of control employing an operating mechanism that is constructed in iaccordance with my present invention; Fig. 2 is a diagrammatic view of a modification of a portion of the apparatus that is illustrated in Fig. 1-; and 3 is a diagrammatic view of an auxiliary control system for governing the main circuits of Fig. 1 in a predetermined manner to be described.

Referring to Fig. 1 of the drawing, the system shown comprises a plurality of supply-circuit conductors respectively marked Trolle d Ground; a dynamo-electric machine emboc lyi'ng an armature A and a field winding F of the series type; a maincireuit variable resistor R; a line switch LS; a control drum 1 for suitably manipulating the "resistor R; an operating mechanism 2, constructed in accordance with my present invention, for the control drum 1 and a vacuumproducing apparatus 3 which may be of any suitable type.

The control system illustrated is of a relatively simple form,since the particular control or other system that is governed by the operating mechanism 2 is immaterial to my present invention. The control drum 1 is shown as embodying a movable contact segment 4 of suitable configuration for successively engaging a plurality of control fingers 5 that are associated with the main resistor R to vary the active circuit value thereof, in accordance with a familiar practice.

The operating mechanism 2 comprises a pinion 6 that is attached to one end of the operating shaft 7 of the control drum 1 and 'is adapted to mesh with a horizontal rack member 8, to the opposite ends of which a pair of pistons 9 and 10 are secured to operate within the respective end- portions 11 and 12 of a suitable operating cylinder. A valve member 13 is disposed to normally effect communication between the end-portion 11 of the operating cylinder and the vacuuiii-producing a1i)paratus3 and is adapted, when actuated to its other position by means of a coil marked Off, to admit atmospheric pressure to the cylinder portion 11.

A. second valve member 14 of a different type is associated with the end portion 12 of the operating cylinder lo normally admit atmospheric pressure to the cylinder and, when actuated to its other position through the agency of a coil marked On, the end portion 12 of the operating cylinder is connected to the vacuuni-producing apparatus 3. a i

The valve members 13 and let are shown as communicating through pipes or passages 15 to a common pipe .or passage 16 that leads to a suitable centrifugal air pump 17 which may be operated by means of an electric motor 18 of any suitable type, or in any other convenient manner. The electric motor 18 is shown as being adapted for direct connection between the supply-circuit conductors, although it will be understood that any other suitable electric-motor connections maybe utilized. The air pump 17 and the armature of the electric motor 18 may be mechanically coupled in any convenient manner, as, for instance, by a shaft 19.

The mechanical operation of the mechanism 2, without regard to the electrical connections effected by the operation of the control drum 1, may be set forth as follows: Upon the energization of both the on and off actuating coils, the cylinder endportion 12 is put in communication with pipes or passages 15 and 16 whereby the air is exhausted from that portion of the operating cylinder, while, on the other hand, atmospheric pressure is admitted behind the piston 9 to the cylinder end-portion 11. The consequent reversal of initial unbalancedpressure conditions causes movement of the piston member toward the right, as shown in the drawin The movement of the piston member may be arrested at any time by merely deenergizing the off actuating coil, whereupon substantially equal degrees of vacuum obtain upon both sides of the piston member; that is to say, upon the outer faces of both pistons 9 and 10, and the balanced-pressure conditions in the two cylinder portions 11 and 12 thus effect a positive and reliable stoppage of the piston movement.

Of course, the movement of the pistons could also be arrested by deenergizing the on actuating coil, whereby atmospheric pressure would obtain in both cylinder portions 11 and 12, but, under such conditions, the pressure of the customary piston leathers or cupped washers against the cylinder walls avould be negligible and the stoppage of the movement would not be reliable. On the other hand, by turning the leathers or washers inwardly, as illustrated in the drawing, which is the reverse of the practice'that is followed in connection with prior mechanisms of the class under discussion, whenever a vacuum obtains in the corresponding cylinder portion, the suction action causes the piston leathers to closely adhere to the cylinder walls and thus set up a relatively great frictional resistance to further move ment of the piston member. Thus, it is much more reliable to deenergize the oil? actuating coil when it is desired to stop the movement of the piston device.

To effect a return of the piston member toward the illustrated position. the two actuating coils Off and On are simultaneously deenergized, whereby atmospheric pressure is admitted to the cylinder portion 12 and the other cylinder portion 11 is put into communication with the vacuuin-producing apparatus 3. The consequent reversion of fluid-pressure conditions to the original state thus causes the desired return movement of the piston device toward the position shown, wherein the piston 9 is located near the valve member 13 and the piston 10 is located as far away as possible from the other valve member 14.

Referring now to Fig. 2, the apparatus shown comprises the piston device, operating cylinder and valve members 13 and 14 as illustrated in Fig. 1, but, instead of effecting communication of the cylinder portions 11 and 12 with the atmosphere under predetermined conditions, the corresponding valve members are actuated to connect the cylinder portions through pipes or passages 20 and 21, respectively, to a tank or reservoir 22 containing any suitable fluid under relatively high pressure. It will be understood, without further description, that the operation of the mechanism corresponds exactly to that previously set forth inconnection with Fig. 1.

The auxiliary control system shown in Fig. 3 comprises, in addition to the actuating coils Off and On of the operating mechanism 2 and the actuating coil of the switch LS, a master controller MO and an auxiliary source of energy, such as a battery B, for supplying energy to the various actuating coils through the master controller in the desired sequence.

For the sake of simplicity and clearness, I have not shown any main-circuit reversing switch in Fig. 1 or the corresponding auxil iarycircuit connections in Fig. 2. It will be understood, however, that, normally, such apparatus will be employed.

The master controller MO is adapted to occupy the illustrated off position and a plurality of operative positions Return, Hold and Forward, corresponding to the governed movements of the main control drum 1.

Assuming the apparatus to occupy the re spectively illustrated positions, the operation of the system may be set forth as follows: Upon the actuation of the master con troller to its position Forward, one circuit is completed from the positive terminal of the battery B through conductor 25, control fingers 26 and 27, which are bridged by contact segment 28 of the master controller, conductor 29, the actuating coil of the switch LS and conductors 30 and 31 to the negative terminal of the battery B.

A second circuit is completed from the contact segment 28 through control. finger 32, conductor 33, the actuating coil On and conductor 34 to the negative c011- ductor 31. Y

A third circuit is completed from the contact segment 28 through the control finger 35, conductor 36, the actuating coil Off and conductor 37 to the negative conductor 31.

The dynamo-electric machine to be gov erned is thus connected through the switch LS, the contact segment 4 of the main control drum 1 and the resistor R, across the supply circuit, as soon as the control drum assumes its initial operative position a as a result of the simultaneous energization of the on and the off actuating coils. The movement of the main control drum 1 may be arrested at any time by actuating the master controller MC to its intermediate position Hold, whereby the off? actuating coil is deenergized to efiectthe previously mentioned balance-pressure condition in the operating mechanism 2, or the control of the off actuating coil may be accomplished through the agency of a limit switch actuated in accordance with the main motor current, as is customary practice in the prior art. The return of the operating mechanism 2 toward the illustrated position may be effected by actuating the master controller to its position Return, thereby deenergizing both the off and the on actuating coils to produce the above1nentioned unbalanced-pressure conditions in the operating mechanism.

It will be understood that the particular device that is governed by the operating mechanism 2 is not material to my present invention and other types of controlling devices or apparatus that are not associated with electrical circuits in any way may be governed in the step-by-step manner hereinbeforc set forth. Moreover, if deemed desirable, instead of employing atmospheric pressure and in predetermined degree of vacuum, as described in connection with Fig. 1, or relatively high-fluid-pressure and a certain degree of vacuum, as set forth in connection with Fig. 2, two vacuums of different values or degrees might be employed if deemed desirable.

I do not Wish to be restricted to the specific circuit connections or arrangements of parts herein set forth, as various modifications thereof may be effected without departing from the spirit and scope of my invention. I desire, therefore, that only such limitations shall be imposed as are indicated in the appended claims.

I claim as my invention:

1. The combination with an operating cylinder, and a movable piston member normally biased toward a predetermined Copies of this patent may be obtained for five cents each, by addressing the end thereof, of means normally open to atmospheric, or other available fluid pressure and located relatively distantly from said predetermined end, means normally closed to said pressure and located near said end, and vacuumproducing means associated with said cylinder.

2. The combinati n with an operating cylinder, and a piston member adapted to travel therein, of vacuum-producing means, a valve member normally open to effect communication of one end of said cylinder with said vacuum-producing means, a second valve member normally open to admit atmospheric, or other available fluid pressure to the other end of said cylinder, and means for reversing the functions of said valve members to effect predetermined movement of said piston member.

3. The combination with an operating cylinder, and a piston member adapted to travel therein, of vacuuni-producing means, a valve member normally open to effect communication of one end of said cylinder with said vacuum-producing means, a second valve member normally open to admit atmospheric or other available fluid pressure to the other end of said cylinder, electrical actuating means associated with the respective valve members, and a controlling device for said electrical means to effect movement of said piston member in the one or the other direction.

at. The combination with an operating cylinder, and a piston member adapted to travel therein, of vacuum-producing means, a valve member normally open to effect connnunication of one end of said cylinder with said vacuum-producing means, and a second valve member mechanically inclependent of the other valve member and normally open to admit atmospheric, or other available fluid pressure to the other end of the cylinder.

In testimony whereof, I have hereunto subscribed my name this 2nd day of August,

ARTHUR J. HALL.

Commissioner of Patents,

Washington, D. G.

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