US2288203A

US2288203A - Electric reciprocating motor

Info

Publication number: US2288203A
Application number: US250349A
Authority: US
Inventors: Thomas J Murphy
Original assignee: Individual
Current assignee: Individual
Priority date: 1939-01-11
Filing date: 1939-01-11
Publication date: 1942-06-30
Anticipated expiration: 1959-06-30

Description

June 30, 1942.

T. J. MURPHY ELECTRIC REC IPROCATIING MOTOR Filed Jan. 11, 1939 2 Sheets-Sheet 1 ATTORN EYS.

J1me 1942- T. J. MURPHY ELECTRIC RECIPROCATING MOTOR Filed Jan. 11, 1939 2 Sheets-Sheet 2 Winn INVENTOR ATTORNEYS,

u msuurlan/gq Patented June 30, 1942 UNITED STATES PATENT OFFICE ELECTRIC RECIPROCATIN G MOTOR Thomas J. Murphy, Stamford, Conn.

Application January 11, 1939, Serial No. 250,349

15 Claims.

This invention relates to dry shaving devices, and more particularly to an actuator or motor for operating the movable cutting member. Although it is shown by way of example as applied to a dry shaving device involving a movable cutter it may of course be applied to the operation of other devices where there is a reciprocating element.

This application is a continuation in part of my prior application Serial No. 754,812, filed November 26, 1934 for Dry shaving device, and which issued as Patent Number 2,146,643 on February 7, 1939.

It is an object of the invention to provide an actuator operated by alternating electrical current which is simple in construction and operates without any make or break devices so that there is no arcing or sparking to interfere with radios and similar devices. It will operate with a minimum of noise and there areno points or similar contacts to burn out.

It is also an object to provide such an actuator which may be easily and effectively mounted within the handle employed for dry shaving and similar devices.

With the foregoing and other objects in view I have devised an improved construction as illustrated in the accompanying drawings forming a part of this application. It is, however, to be understood that I am not limited to the specific details shown but may employ various changes and modifications within the scope of the invention.

In these drawings:

Fig. 1 is a side elevation of my improved actuator as applied to a dry shaving device, a portion of one side of the enclosing casing being removed to more clearly show the construction;

Fig. 2 is a similar view looking from the right of Fig. 1 showing one side of the casing and certain elements in section;

Fig. 3 is a top plan view and partial section, the section being substantially on line 3-3 of Fig. 1;

Fig. 4 is a side elevation on an enlarged scale with one-half the casing removed and certain parts in section to more clearly show the construction;

Fig. 5 is a similar view looking from the right of Fig. 6 showing the casing in section but the interior mechanism in elevation;

Fig. 6 is a detailed partial side elevation and partial section of a portion of the assembly of th operating mechanism immediately below the cutter head;

Fig. 7 is a wiring diagram for one arrangement of the actuator;

Figs. 8, 9, 10 and 11 are similar diagrams of modified arrangements;

Fig. 12 is a side elevation showing a modified arrangement of the core;

Figs. 13 and 14 are side and edge views respectively of another arrangement of the core;

Fig. 15 is a partial section and partial elevation of the operative connecting means between the actuator and the cutter head or other element to be operated;

Fig. 16 is a side elevation of the upper end portion looking from the left of Fig. 15;

Fig. 17 is a top plan view thereof;

Fig. 18 is a partial side elevation and partial section of a connecting contact;

Fig. 19 is an end view thereof;

Fig. 20 is a detail section of a portion of the casing substantially on line 20-40 of Fig. 1;

Fig. 21 is a similar section substantially on line 2|--2l of Fig. 1;

Fig. 22 is a side elevation of the mounting yoke for the armature;

Fig. 23 is an edge view thereof;

Fig. 24 is a top view thereof;

Fig. 25 is a side elevation of a spring support used in the actuator;

Fig. 26 is an edge view looking from the right of Fig. 25;

Fig. 27 is a top plan view of the member of Figs. 25 and 26; and

Fig. 28 is a longitudinal section of an improved means for connecting this device to an outlet for source of power.

The device comprises a casing I made in two

sections

2 and 3, preferably of some molded insulating material such for example as Bakelite or similar synthetic resins, or rubber composition, which casing carries at one end a cutter head 4 and encloses the operating mechanism for the movable element of this cutter head indicated at 5. The connections for this operating mechanism to a source of electrical operating current are at the lower end of this casing, or that is, at the opposite end from the cutter head 4.

This cutter head may be of difierent constructions. That shown comprises a substantially rectangular body including mounting blocks 6 to the opposite sides of which are secured plates I having inwardly extending upper edges 8 on which are transversely extending stationary guard and cutter teeth substantially as shown in the application above mentioned. The longitudinally reciprocating cutter 5 is mounted between the side members 1 and has transversely extending cutter teeth 9 at the inner sides of the teeth [to cooperate therewith for the shaving operation. Both sets of cutter teeth are in spaced relation or separated by a longitudinal slot "I in which is mounted a stationary comb or guard H to prevent entrance of the skin between the two sets of cutter teeth. Thus there is a cuttingdevice on each side of the slot and each comprises a series of guard teeth and a seriessof cutting teeth cooperating therewith arranged with the devices opposed and facing each other. The free ends of the teeth of the two devices extend toward each other but are separated by the longitudinal slot It the same as shown in the prior application. This cutter head may be mounted in the casing by any suitable means such for example as screws I2. It will of course be understood that in using the device as a dry shaver the outer edge or surface of the head is moved back and forth over the surface of the skin for the shaving operation. Also, it will be understood that this actuatoris not limited to use with this particular construc tion of device.

To secure the cutting effect it is necessary that the cutter be reciprocated in a direction longitudinally of the slot III, or that is, transversely of the guard teeth 3 and immediately back of the guard teeth for the proper shearing effect. The teeth of the movable cutter 5 are held against the back of the stationary teeth 8 by a spring |3 pressing the operating pin l4 against the movable cutter 5. This maintains the proper pressure between the teeth and automatically takes up wear. This pin is rounded at its upper end as indicated at l5 to seat in a recess in the lower side of the cutter 5 as shown in Figs. 1 and 4, the rounded end permitting a certain amount of rocking movement without binding. The end of the pin is also preferably flattened on its opposite sides as indicated at It in a plane extending in the general direction of the reciprocal movement to still further reduce the danger of binding.

The actuator for operating the movable cutterv comprises a laminated core l1 made up of a series of plates of magnetic material such as soft iron placed side by side to form a core or poles of the desired thickness and'prevent heating. This core has three magnetic poles or legs, the two outer poles l3 and I9 and the central leg or pole 20. The windings indicated generally at 2| for magnetizing the poles are mounted on the outer poles l8 and I9. Various arrangements of these windings may be used several examples of which are shown in Figs. '1 to 11 which will be described more specifically presently. At the lower or free ends of these poles is an oscillating armature 22 of magnetic material which bridges the spaces means maybe employed for securing the free between the poles and is spaced a short distance preferably having a transverse groove in whichthis member 25 is seated so as to properly posi-- tion the armature and retain it in the proper location. The armature may be secured to the member 25 by any suitable means such as one or more screws 26 each of which is held against loosening up by a lock nut or washer 21. Various ends of the member 25 to the arms of the member 24. In the present case they are seated with in the channel of the member 24 and secured in proper location to give the proper spacing of the armature 22 from the ends of the poles |8, it and 2|) by means of assembling screws 28. Holes 29 may also be provided in the arms of the member 24 to permit entrance of solder into the surfaces between the

members

24 and 25, and after the joint has been properly soldered the assembling screws 28 may be removed. This makes a very strong and rigid connection which will maintain the proper relation between the elements indefinitely. If preferred the

members

24 and 25 may be made in one piece with the joint at the top passing through the center hole for pin 38.

At its upper end the member 24 is mounted on a cross bar 30 of an inverted substantially U shaped spring member or support 3|. The elements of this member are shown as being substantially flat or rectangular in cross section with the upper cross bar 30 seated within the channel shaped cross member 32 of the member 24. A bar 33 is placed on the lower side of the cross member 30, and. attaching screws 34 pass through the portion 32 and portion 3|! and are threaded into the bar 33 to secure the members together as shown more clearly in Fig. 6. The lower free ends of the side members 35 of the spring support 3| are secured to the sides of the center pole 20 of the magnetic core by any suitable means such as the rivets 36 extending transversely through this core. These arms are also turnedthrough an angle of about at the intermediate portions 31 so that they can flex in a plane at right angles to these flat portions as the armature 22 reciprocates. armature 22 reclprocates back and forth toward and from the poles I8 and I9 this motion is transmitted by the yoke or support 23 to the spring support 3|, causing the upper portion thereof, including the cross bar 30, to reciprocate back and forth flexing the spring arms 31 as the poles I8 and I! are magnetized in a manner as will presently be described. They draw the armature 22 alternately to the right and left as viewed in Figs. 1, 4 and '7 to 11 inclusive, while the spring 3| tends to bring it back and retain it in the intermediate or substantially central position.

This upper portion 32 is connected to the cutter member 5 to oscillate the same longitudinally of the head by means of an oscillating assembly comprising a pin 38 extending through the member 32 and threaded into the bar 33 as shown in Fig. 12. This pin has a flange 39 between which and the' top of the bar 32 is clamped a flat spring 40. This spring extends laterally from opposite sides of the bar 32 as shown in Fig. 4 and has downwardly and inwardly extending portions 4| resting on the top of core IT. This supplemental spring 40 is preferably made from flat stock about of an inch wide and augments the spring support 3|. I have found it difficult in practice to make the fulcrum spring support 3| stiff enough and still have it operate without breaking after a while. If this stock were made sufficiently heavy it interfered with the proper working and there was considerable breakage but with the auxiliary spring 40 the spring support 3| may be reduced in thickness to about .020". The auxiliary spring 40 greatly reduces the stresses on the spring 3|. It also assists in lining up the armature 22 more readily with That is, as the the tips of the pole pieces l3, l3 and 20. The operating pin or stud I4 is mounted to slide on the stud 38, and coil spring l3 between the flange 39 on pin 33 and the flange 42 on the pin l4 tends to shift the pin |4 outwardly and holds its tapered and rounded upper end portion l5 seated in the recess or bearing in the bottom 43 of the oscillating cutter 5. This maintains a close connection between the operating pin and the reciprocating cutter member, automatically taking up wear and preventing the development of looseness and lost motion. As indicated above the opposite sides of the tapered end I5 are preferably flattened somewhat as indicated at ii to give free rocking movement of the end of the pin in its bearing in the cutter and prevent cramping or binding. Spring i 3 also holds the teeth of cutter 5 against the guard teeth 3.

With this mounting of the armature 22 and the yoke 23 and spring support 3|, as the work on the cutter increases the ratio of leverage increases proportionately, that is, the effective fulcrum on or point of bending in the flat spring portions 31 moves up and so decreases the liability of stalling. In fact it could never stall the armature, for with sufiicient load the movement of the cutter could come practically to zero as the fulcrum has moved up to it so that the cutter teeth would not be broken. Also, as the leverage increases the movement of the cutter decreases, but the power on the cutter increases so that it can cut through heavier hairs.

Several arrangements of the coils for energizing the poles l3, l8 and 20 for oscillating the armature 22 are indicated diagrammatically in Figs. 7 to 11. I am not, however, limited to these specific arrangements as other arrangements are possible. It will be seen the three connected legs or pole portions l3, l9 and 20 form two magnetic circuits, one circuit being through the legs l3 and 20, the connecting end portion 44 and the armature 22 with the intermediate air gaps. While the other magnetic circuit or path iS legs I9, 20, the connecting portion 45 and the armature 22 with the air gaps between the armature and the poles l9 and 20. The poles are magnetized in such a way so as to reciprocate or oscillate armature 22 by a combination of alternating and direct current coils on the legs, preferably the outer legs l8 and I9.

In the arrangement shown in Fig, 7 there is a pair of alternating current working coils 45 and 41 one on each leg l8 and i9 and connected in series by the lead 48. Coil 43 is connected by lead 49 with one side of a source of alternating current supply 50. Mounted on the legs I8 and I9 are also two sets of direct current exciter coils 5| and 52, and 53 and 54, coils 5| and 52 being connected in series by a lead 55 and the

coils

53 and 54 being connected in series by a lead 56. The opposite ends of the

coils

52 and 54 are connected by the lead 51 to the alternating current coil 41, while the other end of the coil 5| is connected by a lead 53 with the outlet connection of a rectifier 59. The other end of the coil 53 is connected by lead 53 to the inlet of a second rectifier 6|. The inlet of the rectifier 59 and the outlet from the rectifier 6| are connected to the other side 62 of the source of alternating current 50. It will be seen the coils 46 and 41 are wound in the same sense, while the coils 5| and 52 are wound in the opposite sense, and coils 53 and 54 are wound in the opposite sense.

If now we assume that during one half of the alternating current cycle current enters through the lead 49 it will pass through the coils and 41, lead 51, coils 54 and 53, and through the rectifier 6| to the other side62 of the alternating current supply. Thus if the pole I3 is south pole I9 is also south and central pole 20 is north. However, as the coil 54 is wound in the opposite sense to the coil 41 it will tend to suppress the efi'ectof coil 41 or cancel it out, while as coil 53 is wound in the same sense as the coil 46 its effect will be added to that of coil 43 and the magnetization of the leg l3 will be increased, while the magnetization of the leg or pole I! will be decreased or cancelled and there will be a strong force tending to pull the armature 22 to the right or toward the pole I3. During the other half of the cycle current enters through the lead 62, passes through' the rectifier 59 to the coils 5| and 52, by lead 51 to coils 41 and 46, and then by lead 49 to the other side of the A. C. supply 50. At this time as the coils 52 and 41 are wound in the same sense they will assist each other and their effect will be added up on the pole l9, while on the other hand coil 5| is wound in the opposite sense to coil 46 and therefore they will oppose each other thus reducing the magnetization of the pole Hi to practically zero. This will cause heavy pull on the armature 22 to the left or toward the pole I9. Thus the two poles l8 and I9 will be alternatel magnetized to the maximum extent by the combination of an A. C. and a D. C. coil wound in the same sense while themagnetization of the other pole is reduced to a minimum by operation of an A. C. and D. C. coil acting in opposition to each other. Thus a maximum pull is imparted to the armature 22 alternately in opposite directions reciprocating this armature back and forth in synchronism with the A. C. supply, and this motion is transmitted to the movable inner cutter 5 through the supporting yoke 23, spring support 3| and the operating pin l4,

While the armature is being drawn toward either pole is or l9 it fiexes the spring support 3| and also the auxiliary spring 40, and therefore these springs 3| and 40 tend to move the armature back to the central or intermediate position, and when the magnetization is reversed these springs move the armature backwardly during the first half of its movement in the opposite direction. It will be noted that with this arrangement there is no making or breaking of the circuit such as would cause interference with radios or similar apparatus, and there is no spark gap or arcing. The actuator therefore actuates very quietly and effectively with no interference with other apparatus. It is preferred to provide the auxiliary spring 40 with downwardly extending loops or reverse bends 63 in the top or horizontal portion of this spring on opposite sides of its connection to the yoke 23 which permit a certain amount of transverse flexing.

Figs. 8, 9, l0 and 11 show examples of modified arrangements for the coils and their connections which may be used, but there are others. In Fig. 10 the A. C. and D. C. coils are shown with light and heavy lines so that they may be more easily distinguished, but this showing is not intended to indicate that the wires of the different coils are heavier, although they may or may not be heavier as desired.

In Fig. 8 the two A. C. coils are indicated at 54 and 65 connected in series by the intermediate lead 65, and the D. C. coils are indicated at 51 and 68 connected in series by lead 69. The opposite end of the coil 65 is connected by lead 49 with one side of the A. C. supply 56, while the other end of the coil 64 is connected intermediate the

coils

61 and 66 as indicated at 16. The other end of coil 61 is connected to the outlet of the rectiher 59 while the other end of the coil 66 is connected by the lead 1| to the inlet of the rectifier 6|, and as in the form of Fig. '7 the other side 62 of the A. C. supply 56 is connected between the two rectifiers 59 and 6|, that is, to the inlet of rectifier 59 and the outlet of rectifier 6|.

If now we assume that during one half of the cycle current enters through the lead 49, coils 65 and 64 will magnetize the two poles l6 and IS in the same sense as these two coils are wound in the same sense. However, current from the coil 64 flows through the coil 66 to the rectifier 6| and out the lead 62 to the A. C. supply. As coil 68 is wound in the same sense as coil 65 its effect will build up or be added to that of coil 65 and the pull of the pole |8 on the armature 22 will be a great deal more than the pull of the pole i9 and the armature will therefore move to the right. During the next half cycle current will enter through the lead 62, pass through the rectifier 59 to coil 61 and by connection 10 through the

coils

64 and 65 to the other side 49 of the A. C. supply. During this time as the

coils

61 and 64 are wound in the same sense their effects will be built up or added so that the pole I9 is magnetized to a much greater extent than the pole l6 and the armature will be drawn to the left or toward the pole l9.

In the arrangement of Fig. 9 the coils are the same as in Fig. 8 but the leads to the A. C. coils 64 and 65 are reversed. Thus the lead 49 from one side of the A. C. supply is connected to the end of the coil 64 which in the form of Fig. 8 is connected at 16 between the D. C. coils 61 and 68. In the form of Fig. 9, however, this connection 10 between the D. C. coils is connected to the other end of the coil 65 to which the lead 49 is connected in Fig. 8. Now if we assume in the arrangement of Fig. 9 current is entering during one-half of the A. C. cycle through the lead 49 it will pass through the A. C. coils 64 and 65 to the connection 10, to the D. C. coil 66, and the rectifier 6| to the lead 62 at the other side of the A. C. supply 50. As the

coils

64 and 65 are wound in the same sense they will magnetize the poles l9 and IS in the same sense but now the coil 66 is wound in the opposite sense to the coil 65 and therefore its effect instead of being added to or increasing that of coil 65 is opposed to coil 65, reducing magnetization of pole I8 to zero so that pole i9 acting on the armature 22 will draw it to the left. During the other half of the cycle current enters through the lead 62, passes through the rectifier 59 to the coil 61 through the connection 10 to the

coils

65 and 64 and out the lead 49.

Coils

64 and 65 energize the poles in the same sense, but in this case coil 61 is opposed to coil 64 and reduces or cancels out its effect so that the effect of coil 65 is to energize the pole l8 and pull the armature to the right.

In Fig. 10 the A. C. and D. C. coils are shown as wound together, one on top of the other. The coils are connected the same as in Fig. 9 and therefore the same reference numerals are employed to indicate the coils.

In Fig. 11 the connections are reversed from that of Fig. 8, that is the connection between the

coils

65 and 64 indicated at 12, instead of being from the lower end of coil 65 to the upper end of coil 64 as in Fig. 8, connects the two lower or adjacent ends of

coils

65 and 64. The other or upper end of the coil 64 is connected by lead 19 to the connecting point 16 between the two D. C. coils 61 and 66. The connection between these two coils indicated at 14 is also reversed from that of Fig. 8, that is, instead of the upper ends of the coils 61 and 69 being connected as in Fig. 8 the upper end of coil 61 is connected to the lower end of coil 69 and the upper end of the coil 66 is connected by the lead 1| to the rectifier 6|.

In the arrangement of the coils and connections as shown in Figs. 7 to 10 the polarity of the center pole or leg 29 reverses in each cycle. Equally good results are obtained if the connections to the coils are reversed as indicated in Fig. 11 so that the polarity of the center leg 26 does not reverse and thus is secured a practically constant D. C. pole of this middle leg. In fact it seems to require less turns of wire for the same field strength with the latter arrangement. Thus as in this arrangement the A. C. coils 64 and 65 add to each other or are complementary, and the D. C. coils 61 and 68 oppose each other, we get this efi'ect. If we assume that during one half of the cycle current enters through the lead 49 it will pass through the

coils

65 and 64 as indicated, and from the top of coil 64 to the connection 10 where it is carried to the lower end of the coil 68, through this coil to the rectifier 6|, and then by lead 62 to the other side of the supply. In this arrangement the coil 68 opposes the coil 65 leaving the leg I9 to be energized by the coil 64. On the other half of the cycle current enters through the lead 62, passes through rectifier 59 and then through coil 61 to the connection 10, and then through the A. C. coils 64 and 65. In this case the coil 61 opposes coil 64 and coil 65 energizes the pole l8, but the center pole 20 does not reverse thus giving a practically constant D. C. pole of this middle leg.

Very good results are secured by placing the exciter coils on the center leg, but for mechanical reasons it is preferred in this specific device to leave the center leg free of winding. Other arrangements of these core legs may also be used. Thus for example as shown in Fig. 12 the core can be arranged as two U-shaped members 15 each comprising a laminated structure and placed with a leg 16 of each side by side as shown to provide the center pole 20. The coil arrangements of either one of Figs. 7 to 11 may be used on this core.

In Figs. 13 and 14 the two U-shaped laminated cores 15 are spaced laterally from each other providing the poles |8a and |9a corresponding to the poles |8 and IQ of the other forms. The coil arrangements of Figs, '7 to 11 may be used on the legs of this core to magnetize them in the same manner, an A. C. and a D. C. coil being on one leg of each of the two cores 15.

In Figs. 1, 2, 4, 15, 18, 19 and 28 is shown a convenient means for mounting the rectifiers 59 and 6|, connecting them to the actuator mounted in the casing and for connecting them or plugging into the outlet from the A. C. supply, such as any outlet from the standard house circuit. In this arrangement the rectifiers are mounted in an attachment plug cap indicated at 11. This comprises a casing of insulated material made in two sections, only one of which is shown at 16, connected when assembled by any suitable means such as transverse rivets or screws 19. The two rectifiers 59 and 6| are preferably formed by a rectox assembly comprising a suitable number of copper plates side by side in contact and having on one surface a coating of copper oxide which, as is well known in tho. rectox elements, permits electric current to flow in one direction but prevents it flowing in the opposite direction, thus cutting out one half of the cycle of alternating current. However, in the present case I divide this rectifier assembly thus making in effect two rectifiers and there- 1 fore utilize the full alternating current.

As shown in Fig. 28 the rectifier assembly comprises a series of copper plates 89 having on one side the copper oxide coating 8I. Intermediate this series of plates is placed a conductor plate 82 having extending from one side thereof a blade contact 83 projecting from the casing. On the opposite side of the plates 89 is a plate 84 connecting to a lead 85 and carried through a cable 86 to a female contact 81 in another plug 88 having an insulating casing. On the other side of the other half of the rectox plates is a contact plate 89 connected by a lead 90 to a similar contact element 9| in the plug 88. The other projecting blade contact 92 is a part of the contact plate 93 contacting a plate 94 which is separated by an insulating plate 95 from the plate 89. However, as the plates 93 and 94 are in contact current can flow directly from the contact finger 92 to the plate 94 which is connected by lead 98 in the cable 86 to a contact 91 in the plug 88. Plate 93 is preferably somewhat dished as shown so that when the elements are assembled on the cross bolt 98 this plate will yield or flatten as the elements of the rectifier heat up under their rectifying action and thus expand. This spring action of the plate 93 main.- tains the parts in proper contact, but also permits the necessary expansion under heating of the elements.

Mounted in the lower end of the casing I is an insulating support 99 carrying contact pins I09, WI and I02 which are insulated from each other by the support 99. The pin I92 is connected to one of the coils of the actuator, and as when the plug 88 is plugged into the lower end of the casing I pin I02 is in the contact 91 this pin I02 is directly connected through the contact finger 92 with one side of the A. C. supply. Therefore the lead from pin I02 to the coil of the actuator corresponds with the lead 49 of the diagrams in Figs. 7 to 11. When the plug 88 is plugged into the lower end of the casing the pin I99 is in contact 81 and therefore the lead from this pin I09 to a coil in the actuator corresponds to the lead 58 between the rectifier 59 and the D. C. coils. Similarly the pin I9I is connected to the proper coils of the actuator and corresponds to the lead II. It will be seen that this assembly makes an easily manipulated, simple and effective means for connecting the rectifiers with the source of A. C. supply and also connecting the rectifier and this source with the actuator in the proper manner, all that is necessary being to plug the plug 88 into the lower end of the casing I and then insert the blades 83 and 92 of the plug 11 into any standard outlet receptacle connection of a house wiring system.

Details of the contacts 81, 9| and 91 are shown in Figs. 18 and 19. They comprise hollow pins or sleeves I03 having a flange I04 adjacent one end to retain them in the casing 88 and to which the leads in the cable 86 are connected. They are slit longitudinally as indicated at I05 so as to give yielding side walls to receive the pins I09, IM and I92 to give a good grip and electrical contact. The casing of plug 88 is made in two sections, only one of which is shown, and secured together by any suitable means such for example as a screw or rivet I98.

It will be seen from Figs. 1, 2, 4 and 5 that the central pin IN is somewhat shorter than pins I99 and I02. This is to insure that pins I99 and I02 will engage their contacts in plug 88 before pin I9I engages its contact, so that should plug cap 11 be inserted in the outlet receptacle before plug 88 is inserted in the shaver the circuit will be closed through both rectiflers and the D. C. coils before power is applied and therefore prevent both A. C. waves from passing through a single rectifier.

The actuator may be mounted in the casing I by screws I91 passing through the laminated core and threaded into tapped metal members I98 moulded in ribs or bosses l99 in one section, as sec ion 3 of the casing. The free ends of the pole pieces I8, I9 and 29 may rest in notches in ribs II9 on the inner sides of the two

sections

2 and 3 of the casing to steady the actuator and assist the screws I91. After the actuator is mounted in section 3, of the casing the other section 2 may be placed over it and the sections secured together by any suitable means such as screws or rivets II (Figs, 1, 20 and 21) Having thus set forth the nature of my invention, what I claim is:

1 In a device of the character described, a reciprocating element, means for reciprocating the element comprising a magnetic core having spaced poles, a reciprocable armature associated with said poles, means for exciting the poles to reciprocate the armature, a supporting element of substantially U-shape having spring side arms and a connecting bar for said side arms, a stationary support, means for mounting the free ends of said arms on said stationary support, a supporting yoke having side arms connected at one end to the armature and at the other end to the connecting bar of the supporting element, and means for connecting said latter ends to the reciprocating element for operating it.

2. In a device of the character described, a reciprocating element, means for reciprocating the element comprising a magnetic core having spaced poles, a reciprocable armature associated with said poles, means for altenately exciting the poles to reciprocate the armature, a supporting yoke having spaced side arms connected to the armature at one end for carrying the armature, means extending between and connecting the other ends of the side arms of the yoke and connected to the reciprocating element for operating it, and a' spring support for the yoke connected to the latter ends of said arms and adapted to yield to permit oscillating movements of the yoke with the armature and tending to retain the armature in an intermediate position between the poles.

3. In a, device of the character described, a reciprocating element, means for reciprocating the element comprising a magnetic core having three spaced legs connected at one end, associated direct current exciter coils and alternating current working coils mounted on the outer legs for magnetizing these legs, a, movable armature associated with the free ends of the legs and connected with the element for operating it, an insulating support at the other end of the casing, contacts mounted on said support connected with said coils, a plug insertable in said casing having contacts to engage said first mentioned contacts, a second plug having projecting contact blades for insertion in an outlet receptacle to connect the plug with an alternating current supply, a pair or rectifiers in said second plug with one of said blades connected to the outlet side of one rectifier and the inlet side of the other rectifier, and a cable having leads from the other sides of the rectifier and the other blade contact to the contacts in the first plug, and each of said alternating current coils being wound in a sense to alternately increase or suppress the flux in the legs due to the associated exciter coil during each cycle.

4. In a device of the character described, a reciprocating element, means for reciprocating said element comprising a magnetic core having spaced poles, an armature adjacent said poles, means for magnetizing the poles to reciprocate the armature, a yoke supporting the armature having spaced side arms and a cross member connecting said arms, said armature being at the opposite ends of the side arms from the cross member, a spring supporting member having resilient side arms and a member connecting said arms, a support, means for securing the side arms of the supporting member to said support, means for mounting the cross member of the yoke on the member connecting the arms of the supportin member, and means connecting said cross members with the reciprocating element.

5. In a device of the chaacter described, a reciprocating element, means for reciprocating said element comprising a magnetic core having spaced poles, an armature adjacent said poles, means for magnetizing the poles to reciprocate the armature, a substantially U-shaped support having resilient side arms and a cross member connecting said arms, means connecting the free ends of said arms to the core, a yoke mounted on the cross member of said support and having side arms carrying the armature, said armature being spaced from the connection of the yoke to the cross member, and means connecting said cross member with the reciprocating element.

6. In a device of the character described, a reciprocating element, means for reciprocating said element comprising a magnetic core having spaced poles, an armature adjacent said poles, means for magnetizing the poles to reciprocate the armature, a substantially U-shaped support having resilient side arms and a cross member, a supporting means, means connectin the free end portions of said arms to said supporting means, a yoke mounted on the cross member of said support and having side arms carrying said armature at a distance from the connection of the yoke to the cross member, a spring connected 130 said cross member and extending transversely thereof and provided with laterally extending portions resting on said supporting means, and means connecting said cross member with the reciprocating element for operating it.

'7. In a device of the character described, a reciprocating element, means for reciprocating said element comprising a magnetic core consisting of three spaced legs connected at one end, a reciprocating armature at the free ends, means connecting the armature to the reciprocating element, direct current exciter coils connected in a series loop and alternating current working coils on the legs, means for connecting the working coils in series with said loop and a single source of alternating current supply, a rectifier means in the connection between one side of the supply and each of the exciter coils to cause unidirectional current in said coils, and the working coils being wound in a sense to alternately decrease or increase the magnetization of the direct current coils in the legs on each cycle.

8. In a device of the character described, a magnetic core having three spaced legs connected at one end, a reciprocating armature at the free ends, a direct current exciter coil and an associated alternating current working coil on each of the outer legs to magnetize said legs, means connecting the working coils in series with each other and a source of alternating current, means connecting each exciter coil with the same source of supply and in series with the working coils but in parallel with each other, a rectifier in the connection between one side of the supply and each of the exciter coils, one

exciter coil being connected to the outlet side of its rectifier and the other exciter coil being connected to the inlet side of its rectifier, and the working coils being wound in a sense to alternately change the density of the flux in the outer legs due to the associated exciter coils on each cycle.

9. In a device of the character described, a reciprocating element, means for reciprocating said element including a magnetic core comprising independent magnetic circuits including spaced legs having working poles, a reciprocating armature at the pole ends of the core, means connecting the armature with .said element, D. C. exciter coils on the legs of the core connected in a series loop and A. C. working coils on said legs, rectifier means for supplyi unidirectional current to the exciter coils, means for connecting the latter means and the working coils in series with the exciter coils and a single source of alternating current supply, and said working coils being wound in a sense to alter nately change the density of the flux produced by the exciter coils in the working poles during each cycle.

10. In a device of the character described, a reciprocating element, means for reciprocating said element comprising a magnetic core having independent magnetic circuits, a reciprocating armature at the polar extremities of said core, means connecting the armature to the reciprocating element, a direct current coil and alternating current coil on said core for excitation of each of said magnetic circuits, said alternating current coils being connected in series and the direct current coils being connected in a series loop, means for connecting the said alternating current coils and said loop in series with a single source of alternating current supply, rectifier means in the connection between one side of the supply and the direct current coils to cause unidirectional current in said coils, and said alternating current coils being wound on the cores in a sense that during each cycle they alternately change the density of the flux produced in the magnetic circuits by the direct current coils.

11. In a device of the character described, a reciprocating element, means is: reciprocating said element comprising a magnetic system having cores forming independent magnetic circuits including magnetic poles, a reciprocating armature at the poles of said magnetic system and connected to said element. coacting direct current exciter coils connected in a series loop and alternating current working coils connected in series on the cores, and means connecting the alternating current coils and the loop in series with a single source of alternating current supply including rectifier means between said supply and the direct current coils to cause unidirectional current in said coils, each of said coils being wound in a sense that the working coil alternately modulate the flux of the exciter coils to reciprocate the armature.

12. In a device of the character described, a magnetic core comprising independent magnetic circuits including spaced legs having working poles, a reciprocating armature at the pole ends of the core, a D. C. exciter coil and an A. C. working coil on a core leg of each magnetic circuit, means connecting the working coils in series with each of the exciter coils and the exciter coils in a series loop, means connecting the opposite ends of the exciter coils from those connected with the working coils to one side of a source of alternating current supply, a rectifier means between said connection and each exciter coil and said connection being to the inlet side of one rectifier means and the outlet side of the other rectifier means to 'ause unidirectional current to flow in the excite'r coils, said working coils being wound in a sense to alternately change the density of, the flux produced by the exciter coils in the working poles during each cycle, and means connecting the working coils with the other side of the source of supply.

13. In a device of the character described, a

magnetic core having independent magnetic circuits, a reciprocating armature at the polar extremities of said core, a direct current coil and an alternating current coil for exciting each magnetic circuit, said alternating current coils being connected in series with eachother and with each direct current coil, said direct current coils being connected in a series loop, means connecting the alternating current coils with one side of a source of alternating current and means connecting the other side of said supply to the opposite ends of the direct current coils from their connection to the alternating current coils including a rectifier means between said supply and each coil arranged with the supply connected to the inlet side of onerectifler means and the outlet side of the other rectifier means. and said alternating current coils being wound in a sense that during each cycle they alternately increase or decrease the flux produced in the magnetic circuits by the direct current coils.

14. In a device of the character described, a reciprocating element, means for reciprocating said element comprising a magnetic system including a magnetic core having spaced legs forming magnetic poles, a reciprocating armature adjacent said poles for operation thereby, associated exciting coils connected" in a series loop and working coilson legs of the core, means for connecting said working coils in series with said loop and a single source of alternating current supply, rectifier means between said supply and the exciting coils to cause unidirectional current in said coils, and said working coils being wound in a sense with respect to the exciting coils that the working coils alternately modulate the flux in the legs due to the exciting coils during each cycle.

15. In a device of the character described, a reciprocating element, means for reciprocating said element comprising a magnetic core having three spaced legs connected at one end and forming magnetic poles at their other ends, a reciprocating armature at the pole ends connected to said element, an associated exciter coil and a working coil on each of the outer legs, said exciter coils being connected in a series loop, and means connecting the working coils in series with the loop and a single source of alternating current supply, rectifier means between said supply and the exciter coils to cause unidirectional current in said coils each of said working coils being wound in a sense with re spect to its associated exciter coil that the working coils alternately change the density of the flux of the exciter coils in the outer legs to reciprocate the armature.

THOMAS J. MURPHY.