US1238313A

US1238313A - Polyphase-electromagnet brake control.

Info

Publication number: US1238313A
Application number: US16370617A
Authority: US
Inventors: Benjamin Mcinnerney
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1917-04-21
Filing date: 1917-04-21
Publication date: 1917-08-28
Anticipated expiration: 1934-08-28

Description

B. MCINNERNEY.

POLYPHASE ELECTRONIAGNET BRAKE CONTROL. APPLICATION msu 1uLY1a.1914. RENEW@ APR. 2`1, 1917.

bggg @D I Paimed Aug. 28, NW.

UNITED sTATEs PATENT on BENJAMIN MCIN'NERNEY, OF COUNCIL `IBLUFFS, IOWA, .ASSIGNOR TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, -OE' EAST PITTSBURGH, ENISI'SYL- VANIA, A CORPORATION OF .PENNSYLVANIA.

POLYPHASE-ELECTROMAGNET BRAKE CONTROL.

Specification of Letters Patent.

Application ledlJ'uly 18, 1914, Serial No. 851,750. Renewed April 21, 1917. Serial No. 163,79.

lb /JZZ whom it may concern: v

Be it known that I, BENJAMIN MCINNER- NEY, a citizen of the United States, residing at'Council Bluffs, in the county of Pottawattamie, State of Iowa, have invented a new' and useful Improvement in Polyphase-Electroniagnet Brake Controls, of which the following .is a specification,

My invention relates to improvements in electromagnetic means for effecting the release of dynamically actuated brakes such as are employed for retarding the motion of elevators, hoists and other machines.

One object of my invention is to provide a polyphase alternating current electromagnet which does not chatter and is free from the humming of other objectionable noises that usually characterize magnets of this type.

A second object of my invention is to provide an alternating current magnet having an armature that is positively pivoted and is firmly seated in the same position relatively to the pole pieces in successive operations.

Another object of my invention is to provide an clectromagnet having an armature that is provided Witha short lever arm and is of small Weight in order that the movement necessary to operate the brake may be small and the resulting impact shall be substantially eliminated.

A further object of my invention is to l provide an electromagnet of simplified construction Which operates in connection with a mechanism that is subject tov very slight wear and the efficiency of which is not decreased by such Wear of its parts.

A serious disadvantage in connection With the operation of magnet brakes is thetendency for the armature to get out of adjustment because of Wear of its bearing parts. In such cases, the armature does not seat properly because the plane'of its face is out of alinement With the faces of the pole pieces. This condition arises in many cases from the manner in which the armature is pivoted. When the latter is pivoted near its central portion, it is obvious that a very Vslight wear of the bearing parts permits a relatively large lateral movement of the end portions of the armature, thus aliewing the latter to twist ont of alinement with the faces of the pole pieces..

The above described construction renders it substantially impossible to secure noiseless operation for any considerable period, thereby ments necessary to prevent undue vibrations. Another cause of chattering' and vibration Patented Ang. 28, i917.

rendering very frequent adjust-- is'the arrangement or' the pole pieces in the i same plane. In case one or both of the outer pole pieces becomes slightly shorter tl a the others, the tendency to vibrate is greatly increased, as ivill be readily understood.

According to my invention, the armature is pivotally mounted at vits extreme end portions. The pivotal axis is arranged parallel to the plane of the faces of the coacting pole pieces and parallel to the alinement of the pole pieces. By means of this arrangement, it will be obvious that a slight Wear ci the bearing` parts will not permit the armature to move out of alinement with the pole lfaces of the pole pieces. Such a conditicn will arise only when there is a substantial d" ference in the amount of Wear the respective end portions of the armature.

The clectromag'net is provied with plurality of pole pieces, the cut which are-slightly longer than mediate pole pieces which are si icuii by the energizing' -coils. This constrr insures that the armature will be parts which engage its end portion; one of the intermediate pole nieces cannet serve as a fulcrum to produce a rockingY inction. In such an arrangement, lthe magnetic force of the pole pieces is always exerted at a point between the pole pieces which snpport the armature.

The details of my invention will be scribed in connection with theaccompanying drawings in which Figure l is an end view, in elevation, of'a mechanism constructed in accordance with my invention, the electrical circuits being shown diagrammatically. Fig. 2 is a diagrammatic .view of the polyphase electromagnet. Fig. Sis' a side view, in elevation, of the mechanism of Fig. i, the diagram of the electrical connections being oinitted.

A brake m may be a cy tating part or drinn or" a' ISU tion of which is to be controlled by a brake. As illustrated. the wheel m is in the form eustomarilv employed in connection with elevators.- but it will he understood that it may represent'ihe corresponding part of any electrically controlled machine. Two brake shoes s and s. which are pivotally mounted at the respective sides of the wheel m, are normally caused to frictionally engage the periphery4 of the wheel by a spring that is mounted upon an adjusting,r bolt y.

An electromagnet comprises a body member 71 ha ringr outer pole pieces e and e and internualiaie pole pieces f] and al which respectively constitute core members for coils c and r". The pole pieces c and e are slie'l'itly longer than the pole pieces fl and d so thatithe plane of the faces ofthe former is slightly above the plane of the faces of the latter. The electromagnet also comprises an armature member u whichis connected, at its end portions, to levers z' and z". The levers i and i are pirotally mounted at 79 and [/,Eind points 7) and p are so arranged that the pivotal axis of the armature is parallel to the plane of the faces of the pole pieces e and e. \Vhen the coils are energized,.the arn'iature is seated upon the faces ol the pole pieces e and e.

One end of the armature member (L is connected to the brake shoe s by the lever i, a. link a bell-crank lever 7c and an eye bolt Z. The other end of the armature is connected to the brake shoe fr by a similar mechanism i, y", la and Z. The pivotal axis of the armature u. through the points) and 72 is so arrane'ed that-the shortest possible move# ment of the armature operates through the lever mechanism above described to effect the disengagement of the brake shoes. The eye bolts 7 and Z are provided with adjusting nuts for varyin;r lthe positions of the bra kc shoes relatively to the armature.

As indicated diagrammatically in Fig. 1, the coils c and c are supplied With current from a three-phase source. The coil c is connected to line conductors 1 and 2 by conductors' l() and E20y reslfiectively. The coil c is similarly connected to line conductors 2 and i3 by conductors Q1 and 30, respectively. lVhile this system of connections is shown by wa y of example, it is the preferred manner in which current is supplied for energizingr the coils c and c. It is well known that the total power delivered to such a circuit is always `greater than zero and that at least one ot' the coils c and c is always energized to some degree. Tt will be evident, therefore. that a pull will be exerted on the armature men'iber fr, by one or both 0f the pole pieces n and c as lona as the coils are in eireuil. A pull will also be exerted substantially continuously by each of the pole pieces 7. and d.

The mmol-tant advantage of such an arrangement lies in the fart that a constant pull is exerted on the armature between its points of support and there is no periodin which the armature is loosely held against either of the pole pieces. 'lhis feature, together with the manner of pivotally mountingethe armature so as to prevent any twisting' motion, insures that the aru'iature will always be firmly seated upon the coacting pole pieces.

rlhe operation of the mechanism will be readily understood. lVhen the line conductors 1, L) and 3 are connected to any suitable source` (not shown).y the coils c and c will be energized and the arniature a will be drawn downwardly by the magrnetic force of the poles and al and c and c". Since the plane of the armature is parallel to that of the faces of the pole pieces c and e', the armature will be. firmly 'seated upon the pole pieces and retained in that position while, the coils are energized, rilhe downward movement of the armature a operates through the lever mechanisms to separate the brake shoes v and s against the force of the spring' and thereby release the wheel m.

When the magnet is deenergized by opening` the. circuits of the coils c and c', the spring fn operates to effect the engagement of the brake shoes s and with the Wheel m and thus bring the motor or other machine with which it may be connected quickly and safely to rest.

An arrangement in which the coils e and c are connected to a two-phase source is shown diagrammatically in Fig. 2. The coil c is connected to line conductors 1 and 2 by means of

conductors

10 and 20, respectively, and the coil c is similarly connected to line conductors 3 and 4 by means of conductors 30 and 40, respectively. It is understood, however, that the arrangements of the circuits for the coils c and o are shown by way of example only and that l do not wish to limit myself to either of the arrangements shown and described.

The advantages of my invention will be apparent to those skilled in the art to which my invention appertains. The mechanism is composed of few and simple parts. The armature is positively pivoted in such a manner that a slight wear of the hearing parts cannot affect its quiet operation. 4A convenient means is provided for making such adjustments as may be necessary in order that the several moving parts may have their proper relation. The magnet 0perates through a vvery short distance to effeet the engagement and disengagen'ient of the brake shoes and maintains its operative position substantially without noise and witi'iout chattering. Y

lVhat 1. claim and desire to secure hy Letters Patent is:

1. 1n a brake, the comhin-.dion with a brake shoeA` ot a magnet havinfbT a plurality .ture connected to xsaid brake shoe for coacting n ith said outermost pole pieces.

2. ln a brake, the wmbiinltion with an armature which is pivotally supported at its end portions, and a pair ot brake shoes respectively connected to said end portions7 of means l'or exerting a` substantially 0011-' stant pull upon sairl arnnllure between its points' ot' support.

ln a brake, theI emnbination with a pair of brake shoes, ot' a magnet having` a pluralit'v of pole pieces. an armature pivotally supported at its ends and adapted to seat upon at least two ot lsaid pole pieces, and means 'for ailjustably eonneriug each einl o't` saifl armature to one ol. saill brake shoes.

fl. lira brake. the Combination with a brake shoe. ot' a magnet havlngl a plurality ot' alimal pole pieces, the outermost ol which project be'vonrl the plane of the others', and an armature connected to said brake shoe an l having a pivotal axis substantiall)r parallel to the plane oi tlieflaees oi' tho outermost pole pieces.

ln a brake, the, eonlhinatimi with a laalto shoe, of a magnet having a plurality7 oi' alined pole pieces. the outermost ol which project beyond the planeI ot the others, and an armature, connor-,tml to said bralte shoe anrl havingT a pivotal axis suhstantiall)Y parallel to the alinement of said pole pieces, said armature being adapted to seat upon the, outermost pole pieces.

5. In a brake, the etanbination with :1- hralie shoe, of a magnet having a plurality of alined pole pieces, the outermost of which project beyond the plane of the faces ot' the others, coils upon intermediate pole pieces, and a pivotally mounted armature connectell to said brake shoe for eoacting with the outermost 'pole pieces.

7. ln a brake, the combination with a brake shoe, of a magnet having' a plurality ot alined pole pieces, the outermost of which project bevond the plano of the faces of the others, coils upon intermediate poleI piel-es, alnl an armature connected to said brake shoe having a piwlal axis substantiall \fY parallel to the alim-nient of said pole pieees and adapted to seat upon the onterinost polo pieces.

ln a brake. the combination with an armature which is pivotall'v supported at its end portions.y and a pair olt brake members connected to lsaid armature and alinetl with the axis of pivotal support. ol means for eX- erting' a substantiall)v constant pull upon sail armature between its points of support.

Wil nesses:

linnn lV. HUGHES, llnxnv Pn'rnnsox.