US806009A - Automatic motor-starting resistance. - Google Patents

Description

PATENTED NOV. 28, 1905.

R. SCOTT. C MUTDR STARTING RESISTANCE. APPLICATION FILED JUNE 15, 1904.

AUTOMATI I nven tor Wi messes Httomegs UNITED STATES PATENT OFFICE.

RALPH SGOTTQOF WILKESBARRE, PENNSYLVANIA; AUTOMATIC moron-swarms nEsisTA'N'cE.

Specification of Letters Patent.

Patented Nov. 28, icon.

' Application filed June 15, 1904. Serial No, 212,744.

To all wwom/ may concern:

Be it known thatI, RALPH SCOTT, a citizen of the United States, residing at Nilkesbarre, inthe county of Luzerne and State of Pennsylvania, have invented a new and useful Automatic Motor-Starting Resistance, of which the. following is a specification.

This invention relates to improvements in automatic motor-starting resistances, and has for its principal object to construct an automatic starting resistance of the most simple and eflicient character and onefwhich may be readily adjusted in order' to cut out the resistings, and particularly pointed out in the aption.

. invention.

pended claims, it being understood that vari ous changes in the'form, proportions, size, and minor details of the structure may be made without departing from the spirit or sacrificing any of the advantagesof the inven- In the accompanying drawings, Figure 1- is a sectional elevation of an automatic starting resistance constructed in accordance with the Fig. 2 is an elevation, partly in section, illustrating a slight modification of the invention. i

The device forming the subject of the present invention is one of that general class in whichwhen the motor-circuit is completed a resistance is cut in in order to prevent sudden starting of the motor, and such resistance. is

gradually cut outuntil it is finally eliminated,

at which time the motor will have attained full speed.

The various working parts of the apparatus are mounted on a suitable slab or base 1, formed of non-conducting materialioandprovided'with openings 26 for the passage of securing-screws or other fastening devices. At

a point near the top of the base-plate isse-' cured a bracket 5, held in position by screws orsimilar fastenings 3, and this bracket supports a dash-pot 2, formed of any suitable ma- -terial,the dash-pot being secured to the bracket .suitable manner to the slab or base 1.

resistance-bar 8.

by a fastening means-such, for instance, as a pin 4. In the upper end of the dash-pot is an air-opening 6, preferably tapered to form a valve seat for the reception of a valve 6', which may be in the form of asphere. Under pressure of air in the dash-pot the valve will be forced to its seat and close the opening 6; but

when pressure is reduced the valve falls from; 1

its seat and allows air to flow into the dash-p ot. Within the dash-pot is placed a plunger 7, which may be formed of graphite'or other suitable material, and depending from thev plunger is a resistance-bar 8 formed of any suitable material, such as carbon or carbon compounds, the lower end of the resistancev cessively cutting out portionsof the resist ance, these bars from top to bottombeing successively brought into engagement withcarbon or other contact-blocks 20, carried by a supporting-bracket-i'l, that normally comes into engagement with the contact-rings 23 by screws 9. to an inverted-cup-sha-ped casing 15,

formed of soft iron, said casing forming a housing orclosure for a solenoid-coil 11 which is insulated'from the housing by a ring or cylinder 21, that extends comp'letely'around the solenoid-coil. The solenoid and the insulating material are held in place by a spool .magnetic screws 22, and the solenoid and its casingas a wholeare rigidlysecure'd in any Fitting within the solenoid is an iron core12, at the lower'end of which is a collar .or flange 25, extending outward and of a diameter equal at least to the diameter of the casing or hous- 1 ing 15 in order to render the magnetic field-- of the solenoid more effective and to retain the core in elevated position with a minimum expenditure of energy. Secured to the core and moving longitudinally with said core is'a rod 14, formed of brass or other non-magnetic material .and forming a support for the an opening in a guiding-bracktlS, that is secured to the lower portion of theslab or and from thence to the motor-field.

screw 31, and the enrged shoulder at the top of the reduced poron of the rod serves to limit the upward movementv of the core by engaging against arid bracket.

Returning now to the dash-pot, 36 desig rates a nipple in communication with the dash- ;pot and having a valve-seat 37 and a port 35 leading to the outer-air. The nipple is threaded for the reception o" a needle-valve 38, profl/lili :nilled or knurled z nob 33, by which re valve may be adjusted inorder to control the discharge of air from the dash-pot.

At one side of "he slab are binding-posts M M, to which the main line-wires are conected. {in the opposite side. of the base are riding-posts M, A, and F. One of the linewires leads from binding-post M to bindingpost M and from thence to the motor. From f." 1i! iing post M leads a wire 40 to the sonoid-core, and from thence to bindin -post Asceond wire s1 leads from the binding-post M to the bracket B, which is connected, through therod 141:, to the resistance-rod 8 and from thence to contacts 20, bracket 17 and springs 19 to the housing or casing 15 and by wire 42 to the binding-post A, from whence it passes to the motorermature.

When the circuit is closed, the solenoid is energized and gradually raises the core 12, the speed at which the core is elevated being dependent on the extent to which the valve 38 aided its outer e opened, and by altering the size of the pasirom the dash pot the speed may be increased or diminished in accordance with circnmstances. As the core is elevated the successive contact-rings :23 are brought into en-.

gagement with the contact-blocks 20, and as these are disposed at diametrically opposite points good contact of one or both is at all times assured. On the completion of the upward movement, which may occupy any predetermined length of time, the flange 25 of the'spool comes into engagement with the nonmagnetic screws 22 and is held slightly away from the soft-iron casing or housing 15, so that when the circuit is broken the core may fall and will not be held by residual magnetism, as will'be the case if the flange comes into directcontact with the casing or housing.

in Fig. Qis illustrated aslight modification oi the invention, the resistance-bar 8 in this instance being in the form of flat plates or slabs provided with a plurality of contact-buttons 23, and at the top of each of the plates is a metallic contact-strip 23". The resistance-plates in this instance are stationary, and

the contact-blocks 20 are carried by posts 17,

4 projecting from a central block 29, that is seance is gradually cut out until the plates 23"- are reached, at which time the resistance is wholly eliminated. The circuit in this instance. may be traced from binding-post N through the solenoid to one of the end plates 23, thence through the rcsistance'to block 20' and across to the opposite block 20, thence through resistance to plate 23", and finally to binding-post A. The resistance in this case is intended to be in series with the armature of a motor. In both cases the period of time required for cutting out the resistance may be adjusted in accordance with requirements, and when the circuit is broken the weight of the core 12 and the associated parts will cause the contact-buttons to again engage with the last contact of the resistance-bar, so that all" resistance is held in the circuit in readiness for another operation.

Having thus described the invention, what is claimed is- 1. In a device of the class specified, a resistance-bar, a plurality of contact members on said resistance-bar, a contact member for engaging the contacts of the resistance-bar, said contact member and resistance-bar constituting two members of a circuit-controlling device, one

' of which is movable with respect to the other,

a solenoid having an iron casing, a movable core connected to the movable member and having an enlarged flange that is attracted by the casing when the solenoid is energizedI'a non-magnetic spacing means preventing contact between the flange and the casing, and a dash-pot for controlling the speed of movement of said core. I

2. In a device of the class specified, a solenoid, a movable core. a resistance-bar carried.

by the core, a plurality of contact members on said resistance-bar, contact members carried by the solenoid for. engagement with the contacts of the resistance-bar, a plunger secured to the resistance bar, and a dash-pot into which said plunger extends.

3. In a device of the class specified, a solen oid, a solenoid-core, a resistance-bar supported by the core, a plurality of contact-rings on said resistance-bar, a pair of diametrically-on posed contacts carried by the solenoid for engagement with the contacts of the resistancc bar, a plunger secured to the resistance-bar, and a dash-pot into which S21 id plunger extends.

4. In a device of the class specified, a solenoid, a solenoid-core, a, resistance-bar secured to the core, a plurality of spaced contact-rings carried by the resistance-bar, a pair of springheld contact-blocks supported by the solenoid and adapted to engage the contact-rings of the resistance-bar, a plunger secured to the resistance-bar, and a dash-pot into which said plunger extends.

5. In a device of the class specified, a solening, a. resistaucehzu:

' an enlarged fian e gage the contacts 0;?

seilic red seen:

oidhavingazso'ft i 1a cesinp nrhonsing, a core having an enlarg flange the: is attracted by the casing or housing; when the scleneid is energized'anon-in net r m? means pre- Venting cn'ntzics n en n s end the scppei ued by the cere end of spaced contacts; a conce ing and adapted to en the re istance-bar, and means for retarding movement of the scicn bid-core In a having a plnrelxi tact carried by tl device of the class specified, a s0ien- 0351, an inverted --cn.p like easing or housing for said SOlGDOlCl, a men-magnesia: speel for the s0- -len0id-winding, said spool having an enlarged flange, enon-magneticrneans for securing said flange to the'casing insulating material surrounding the scleneid i inding, a core having adapted '50 en n e the seent direct nmcle bccuring means a tween the core ts the ccre, guidingind the casing, 21-2116" nncedmr; a cylindrical deslvpot into which said i plunger enters, a valved air-inlet for the dashl pet, a nipple projecting from the dash-pot l and provided with an air-outlet port, anda l needle-valve carried. by the nipple and serw l ing to adjust the effective area of said outlet- 1 port.

' in testimony that I claim the foregoing as l my own I have hereto niiixed my signature in 1 the presence of two witnesses.

l l I l l l EJBJLPH SCOTT.

Vi 'itnesses;

FRANK Seem, Tees. M. HERBERT.

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