AU488024B2 - Audible alarm fora synchronous motor - Google Patents

Description

82,974

invention relates Generally speaking, the present to a buzzer that to an audible alarm and more specifically wherein a buzzer anvil ooperates with a synchronous motor, metal-containing extends from the motor and a bight-shaped next the buzzer anvil buzzer arm is carried by the motor against the anvil upon ener- in a position so as to vibrate motor. gization of the winding of the buzzers are commonly Audible alarms in the form of motors. In these com- used in conjunction with synchronous synchronous motor serves a binations, the AC winding of a an alternating electromagnet secondary function of providing this type come in a variety for a buzzer arm. Buzzers of pivotally mounted near a of'sizes and shapes. Many are a portion of the motor synchronous motor so as to engage Many have accompanying pivot acting as an electromagnet. rings, and adjustment set posts, torsion springs, retainer of buzzer can be found in screws. One example of this kind 'Pat. NI.4 5 9 Operated U.S.3,69 1, A Motor Driven Timer With Cam and J.F. Gluth. Buzzer Construction, by R.M. Bassett a buzzer for a The present invention provides to assemble and less costly synchronous motor that is easier This buzzer does not than many pivotally mounted buzzers. setting for the gap between require as precise an adjustment anvil as is needed in a pivot- the buzzer arm and the buzzer present invention produces ally mounted buzzer. And, the desirable, buzz than any of a louder, and therefore more

the pivotally mounted buzzers. of the present inven- Accordingly, it is a feature cooperates with a tion to provide an audible alarm.that an audible sound. Another fea- synchronous motor to produce Q 488,0 24

82. 9 7 4 ns

ture of the present invention is to provide an audible alarm

that utilizes an AC winding of a synchronous motor to pro-

vide an alternating electromagnetic field in which a buzzer

arm vibrates. Another feature of the present invention is

to provide a generally bight-shaped buzzer arm carried

by a synchronous motor, wherein a portion of the buzzer

arm is located near and vibrates against a buzzer anvil ex-

tending from the motor. Yet another feature of the present

invention is to provide an audible alarm that includes a

buzzer anvil as an integral part of an inner field stator

pole member of the motor. Still another feature of the

present invention is to provide an audible alarm that is

riveted to a synchronous motor. Yet another feature of

the present invention is to provide an audible alarm that is

welded to a synchronous motor. Still another feature of

the present invention is to provide an audible alarm that

includes a follower projection as an integral part of a

buzzer arm for engaging a timing cam. Yet another feature

of the present invention is to provide an audible alarm that

includes a cylindrical pin fixedly carried by a buzzer arm

for engaging a timing cam. These and other features will

become more apparent from the specification taken in conjunc-

tion with the accompanying drawings wherein: FIC,. jF4URB 1 is a front view of a synchronous motor with a buzzer attached to it by rivets; FIG IFGR 2 is a cross section of the motor and buzzer FIG illustrated inj4GEf6 1 taken along a line 2 2; FIG. FIG I 4GFR3 is the cross section as shown inAe6iR5 2 butwith a buzzer anvil formed as part of an inner field

stator pole member; and

4 488,024

82,9 7 4 ns

S4 is a pictorial view of the motor and buzzer

f PI I 1 in conjunction with a timing cam. FIG. Referring now to4/PIURH 1, a synchronous motor

includes a buzzer assembly shown generally at 12. It should to oe understood that the invention is by no means limited

the motor illustrated in the figures. The buzzer assembly 12 of synchro- nay be fitted to many different shapes and styles

nous motors with only minor adaptations in mounting. FIGS. fd The motor illustrated inFIGUR 1, 2, 3 ,r 4 a winding. includes a housing 14, a permanent magnet rotor 16, an of wire 18, and a set of stator poles 20 which includes

inner field stator pole member 22 and a U-field stator

pole member 24. FIGf Referring now to GR 2, motor 10 includes an which inner core 26 which carries a rotor shaft 28 about a rotor 16 rotates. A buzzer anvil 30 is secured about 34 and stepped portion 32 of core 26 between a shoulder

inner field stator pole member 22. Buzzer anvil 30 can be a made of a material, such as iron, capable of providing to the path of magnetic flux from the center of the motor

buzzer assembly 12. In another embodiment of motor 10, shown as FIG. this inJ 3, the same buzzer assembly is used, but in of an inner field example a buzzer anvil 30' is formed as part

stator pole member 22'. The operation of buzzer assembly 10 and 12 is the same for both embodiments of motors F76. 1 as Buzzer assembly 12 is illustrated inZFIGURE the housing of motor a bight-shaped buzzer arm 13 riveted to used. with rivets 36. Many different attachment means can be departing from to connect buzzer arm 13 with a motor without 488,024 the spirit and gist of the present invention. Another means Fla. of attachment is shown in1±e~M 4 as welding 38. Buzzer assembly 12 includes a follower projection

One form of projection 40 is cylindrical pin 42 staked F1. FI. to the buzzer as shown inlP+Gi 1. i P 4 shows a varia-

tion of follower projection 40 as a formed projection 41

integral with the buzzer.

Buzzer arm 13 further includes a slot 44, a strength-

ening rib 46, and a contacting distal end 48. Slot 44 allows

end 48 to vibrate freely without imparting a lot of vibra-

tiont- follower projection 40. Rib 46 stiffens buzzer arm

13 in the area where it extends toward follower projection

Buzzer arm 13 may be made of any number of flexible

materials such as thermo-plastic. The only material requi-

site for successful operation of the buzzer is that a magneti-

cally attractable material be carried by buzzer arm 13 near

buzzer anvil

FIGURE 4 shows motor 10 mounted on a device such

as a timer switch 50. A timing cam 52 is carried by timer

so that an internal profile groove 54 of cam 52 is engaged

by follower projection

In operation, winding 18 of motor 10 is energized

by an alternating current power supply (not shown). This

results in an alternating magnetic field appearing in the

set of stator poles 20. Rotor 16 rotates within the magnetic

field in a manner well known and understood by persons skilled

in the art. The alternating magnetic field also appears at a

distal end 56 of buzzer anvil 30 and intermittently attracts

distal end 48 of buzzer arm 13. The impacting of buzzer 6 488.024

82.974 ns

in an audible buzzing arm 13 against buzzer anvil 30 results sound. the buzzer The air gap between the distal end 58 of (indicated as L1 inlj 1) must arm 13 and anvil 30 to attract be small enough to allow the magnetic field small as to diminish buzzer arm 13 to anvil 30 but not so of the air gap the sound level of the buzzer. Adjustment and slightly deforming can be easily accomplished by bending the buzzer arm 13 near the loop. in an appli- The buzzer and motor may be employed turned on and off. cation where the buzzing is selectively FIG. One such example is shown in 4 where motor 10 is

A cam 52 engages follower attached to a cam-actuated timer 50. gap L1 between a non- projection 40 so as to change the air pulled away from anvil buzzing condition where the buzzer is is allowed to and a buzzing condition where the buzzer vibrate against the anvil.

488, 024

Claims (1)

1. 82,974 ns THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:- 1. In a synchronous motor having a rotor, a winding,

   and a set of stator poles, an audible alarm, comprising:

   a. a buzzer anvil electromagnetically connected

   to said stator poles projecting from said synchronous motor;

   and

   b. a bight-shaped magnetically-attractable

   buzzer arm carried by said motor juxtaposition to said buzzer

   anvil and intermittently engaging said buzzer anvil upon

   energization of said winding, whereby said engagement of said

   buzzer arm and said buzzer anvil produces a buzzing sound.

   2. The audible alarm as recited in claim 1 wherein

   said set of stator poles include an inner field stator-pole

   member and an U-field stator pole member and said buzzer

   anvil is an integral part of said inner field stator pole member.

   3. The audible alarm as recited in claim 1 wherein

   said anvil projects out from said synchronous motor in a

   direction substantially at a right angle to the rotational axis of said rotor.

   4. The audible alarm as recited in claim 1 wherein

   said buzzer arm is mechanically attached to said synchronous motor with rivets.

   The audible alarm as recited in claim 4 wherein

   said buzzer arm is attached to said synchronous motor by a weld.

   6. The audible alarm as recited in claim 1 wherein

   said buzzer arm includes a follower projection for engaging

   a timing cam.

   7. The audible alarm as recited in claim 6 wherein 8 488,024

   82.974

   formed integrally with said said follower projection is

   buzzer arm. in claim 6 wherein 8. The audible alarm as recited a cylindrical-shaped said follower projection comprises buzzer arm. pin fixedly carried by said 1977. DATED this 8th day of February, P.R. MALLORY CO. INC.

   Attorney: ROBERT G. SHELSTON Fellow Institute of Patent Attorn ysof Australia of SHELSTON WATERS

   488,024

   82, 97 4

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