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Publication numberUS1674245 A
Publication typeGrant
Publication dateJun 19, 1928
Filing dateOct 9, 1923
Publication numberUS 1674245 A, US 1674245A, US-A-1674245, US1674245 A, US1674245A
InventorsC. Gaynor
Original AssigneeSaid Arthur C
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
US 1674245 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

June 19, 1928.

A. C. GAYNOR ET AL ELECTRIC BELL Filed oet. s, 192s Mh 6. @ay/vor Patented June 19, 1928.




*Application filed October 9, 1923. Serial No. 667,475.

This inventiony relates to an electric bell and, more particularly, to a bell of simplified construction capable of being operated efficiently by either direct or alternating current. l

Accordingly, an object of our present invention is to provide a bell or gong operating mechanism in which the losses of electric energy due to eddy currents and other losses associated with the use of alternating currents may be decreased or eliminated.

Another object of the invention is to provide a bell in wliicha maximum noise may be generated from a given gong with a mini mum of electricity.

Other objects are, to 'provide a bell in `which as much electric energy as possible is taken from the source, Iconverted into the kinetic energy of the-hammer, and in turn imparted to the gong with the least Vpossible loss Vof energy in impact.. Further objects of the invention are to provide improved contact means in an electric bell by which the electric current is tapped for a maximum time, of an electromagnet core of high permeability and a supporting frame in which eddycurrents are reduced to a minimum. Additional objects of the invention are to provide an improved and simple type of hammer and arm, and a supporting base of simple and inexpensive construction.

lVith these and other objects in view, the invention comprises the bell and actuating mechanism disclosed and set forth in the following specification and claims.

The various features of the invention are illustrated in the accompanying drawings in which;

Fig. 1 is a plan view, partly in section, of a bell embodying a preferred form of the invention the gong being illustrated inV dot and dash lines,

Fig. 2 is alongitudinal sectional view of the bell, taken on line 2 2 of Fig. 1,

Fig. 3 is a longitudinal sectional view of a portion of the bell actuating mechanism taken on line 3 3 of Fig. 1, y

Fig. 4 is a perspective view of the hammer actuating mechanism,

Fig.` 5 is a perspective view of a supporting frame for the hammer actuating mechanism, and n v u Fig. 6 isa detail view of a spring for actuating the hammer of the bell."

In the present invention, the striking portion of the hammer is carried on an arm that is substantially rigid and linflexible under `the impacts and impulses of the actuating mechanism so that the loss of energy in bending or flexing this arm is eliminated or reduced to' a minimum. This arm is pivoted at one end on a supporting frame .which also supports the actuating electrovthe electromagnet, the circuit is closed through a stationary contact supported on an insulated spring and a contact mounted on a leaf spring on the hammer arm positioned to press against and slightly displace the stationary contact when the arm is thrown away from the electromagnet. A sliding contact is thus provided thereby insuring a clean, effective contact and a period of contact of considerable length. This enables the electric current to pass through the electromagnet and to act on the hammer arm for a maximum portion of the period of vibration or oscillation. This arrangement also provides a ver stron impulse of restitution or reboun whic throws the hammer away from the gong immediately after the stroke and thus prevents a dampening effect of the hammer on the gong. A high eficiency of the electromagnetic action is obtained by making the core of the electromagnet of a laminated structure and of metal of high permeability and by so slitting the supporting frame as to eliminate eddy currents thus'avoiding loss of energy.

Referring more particularly to the accompanying drawings, the actuating mechanism embodying the invention is illustrated in connection with a gong 10 mounted on a base 12 of suitable construction. The actuatingmechanism is contained within a cover The elements of the bell operatin mecha- 21 and is held in placeiat one end against this Wall by means of a core 22 of an electro-magnet 24 mounted on the back of the frame and spanning the distance from `the back of the frame to the opposite or side wall 25 of the` cover and at the other end by an indentation 26 in a wall 27 of the cover. The frame 20 yis formed of a sheet of metal,

. preferably brass, stamped to form a back plate 28 to the upper wall of the cover and portion or supporting plate 28, on which the core'22 is mounted, a number of upper side members 29, lower side members 30 and spacing lugs'32 and 34 extendingfrom the tothe base respectively. The front edges VV.of the side members 29 and 30 notched to receivea front plate or slab of insulating material 36. notched to fit into the notches of the side plate. VThe frame is shaped and adapted to lit Vinto the front part ofy the f coveinvith the slab 36 against the wali 2l .i and held tightly inposition against the.V front wall of the Acover by means of the electromagnettcore 22inounted,on. the rear face of theback 28 ofthe trame andby the yindentaf tion 26. Y

with the gong'by asuitable spi'in heavy sheet metal, the hammer being pressed into the desired cone shape in the stamping operation in which the arm is formed. 'A

`..pair of pintles 46 are `formed as the. arm is stamped out to extend sidewise from the opposite end of the arm 42 and be journalled in notches 48 inthe lugs 38 and 40. These pintles may beV easily, inserted into the notches when the Vframe is out of the cover and .are held inlposition in the notches by the vside walls of the cover when the frame is inserted in the cover.

The arm 42 is intermittently vibrated to fcausethe hammer 44 to strike the gong 10 when vthe electro-magnet24and core 22 are energized and rto be thrown out of contact g device when the energization of the electro-magnet is interrupted. This spring device is preferably formed of a flat or leaf spring 48 having a hooked end portion 5() adapted to be in' sorted in a notch '52 inthe endof the plate 2Ol andfreturn over theopposite face of the plate.V The free end of the spring extends towards the arm 42 and presses thereagainst When the electro-magnet 24 is energized,

it attracts the` arm 42V directly; 'causing it to swing on the pivoting pintles 46 and causing the hammer 44 to strike the inner surface electro-magnet is exerted on the arm 42 at a locality intermediate the pivotal point and Y at a locality adjacent the electro-magnet core nisin are mounted principally on a rame 20, 22 which fits in the cover adjacent aside wall of the' gong l0. The attractive force of the flexible, a considerable portion of the force Y Vof the electro-magnet.wouldbe exerted in flexing the arm before this force would be transmitted to the hammer. This lag in the transmission of the impelling 4force tothe hammer would, in addition tend to holdthe hammer in contact with the gong after the Vimpact and thus tend to dampen the vibration of the gong, and deaden the sound. Y

To obtain the maximum Veiiiciency inthe utilization kof the electro-magnetic force generated in theelectro-magnet, therefore,

the arm 42 is. made substantially'V rigid so that it suffers no substantialjflexing under force promptly and Y undiniinished to -the hammer 44, while at the same time permitting the returning forceV of the spring 48 to strengthen tlie'reboundiof the hammeras it strikes the (gong and thus immediately throw it outv of contact with the' surfaceof the` gong.V By makingthe arin 42 of the reV `quired stiffness, therefore, the foices of the electromagnet and of the springr4'8` are as eectiveasthough they acted directly on rthe,

hammer 44.

l The current for energizingi'th, electro-y magnet is supplied from a supply main v54 to a binding post 56, Vwhich isconnected to the electro-magnet 24 by means of aconducthe forces exerted onV it and transmits this.


tor wire 58. From the electro-magnet 24,

the current is returned through a conductor.

60 to a AContact snpperting member 62 mounted on the plate of insulating `material.

36Y and insulated from thel cover V14. Y A spring 64 is mounted on the arm 42 to extend toward the contact supporting member 62 and is provided atfits free end with a contact 66 adapted to contact with'v a stationary contact v68 mounted on the member 6221s the spring 48 swings the yarm 42 away from the electrofinagnet 24. VWhen the contacts 66 and'68 are in Vcontact the Vcurrent returns through the spring v64 to vides a spring o r resilient support for thev Contact 68 so that it is ydisplaced slightly bythe pressure of the spring 64. The ydis- V placement of the Contact 68'depends von the force withwhich the arm 42V is thrown back Vand forth, thus affordingra'self adjusting les we 'Y support for the contact 68 that enables the usual type of adjusting screw to be dispensed with. The displacement of the contacts also causes a slight sliding between the contacts that keeps the contact surfaces clean and insures a contact. By means of this yielding contact, moreover, the contacts are in contact withv each other for a longer portion of the period of vibration and a larger quantity of current can be tapped from a given source. The contact support 62 is preferably formed of a U-shaped piece of metal 74 secured to the insulating plate 36 and the conductor 60 by means of a rivet 76.

To increase the efficiency in transforming the electric energy of the current flowing through the coil 24 into magnetic force aeting on the hammer arm 42, the core 22 is made of a laminated structure and of a highly permeable metal. This is preferably done by bending a strip of permeable metal of the proper size into folds extending longitudinally of the core and pressing these folds together into close contact, at the same time giving the folded mass an outer cylindrical shape as the folds are compressed together. As this operation may be carried out equally well with metals of different properties, no difficulty is experienced in making the core of a metal of high permeability. The core is mounted on the plate 28 of the frame 20 by inserting its end in a hole 7 8 in the plate. The compressibility of the laminated core aids materially in readily effecting a tight lit of the core in the hole 78 in the plate 20. The plate is slit at 80 from the hole 7 8 to the end of the plate to break the electric circuit through the plate about the core and thus eliminate eddy currents about the plate as the magnetism through the core varies or is reversed in the case that alternating currents are used. The slit 80 also permits the hole to be very slightly enlarged by spreading the slit and to contract on the end of the core 22 inserted therein and thereby provides a resilient and gripping hold on the core.v

The gong and gong operating mechanism may, of course, be mounted on any suitable base. The present invention, however, provides a base of particularly cheap, simple and durable construction byl stamping the base of sheet metal and stamping a supporting post for the gong at the time that the base is stamped out. This is done by bending the portion 82 beneath the gong upwardly at a right angle to the main portion of the base and extending it horizontally to form a fiat lug 84 on which the gong l0 may be mounted by means of a rivet or bolt.

As changes of construction could be made within the scope of our invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having described the invention, what we .claim and desire to secure by Letters Patent 1s:

1. A device of the type described which comprises, an electromagnet core, and a base plate having a hole in which the end of said core is received and having a slit extending from said hole to the edge of said plate, permitting said hole to contract onto and hold the inserted end of the core.

2. A device of the type described which comprises, a casing, a frame mounted in said casing having a iiat plate extending longitudinally of said casing and side walls, and a notch in the end of each side wall parallel to said plate, a vibrating arm having a pair of pintles pivoted in said notches and held in place by the adjacent wall of the casing, a leaf spring bent through a notch in and gripping said plate and pressing against said arm, and an electro-magnet on the opposite side of said plate.

3. An electric bell which comprises, a casing, a frame in said casing fitting against one side and the adjacent walls of said casing, an electro-magnet extending from said frame to the opposite wall of said casing holding one end of said frame in position, and an inward indentation positioned in an adjacent side wall to retain the adjacent end of said frame in position.

4. A device of the type described which comprises, a frame, a vibrating arm pivoted at one end of said frame, and a. leaf spring pressing against said arm and having a hooked end engaged about the end of said frame, a covering casing for said frame and acting to hold said spring in position.


Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2418863 *Mar 23, 1945Apr 15, 1947Barber Frank GAlternating current electric bell
US3500393 *Oct 21, 1965Mar 10, 1970Int Standard Electric CorpBalanced armature magnetic percussion sounding device
U.S. Classification340/396.1, 336/234
Cooperative ClassificationG10K1/26