US2813937A - Guided push rod mechanism - Google Patents

Description

Nov. 19, 1957 E. J. DIEBOLD 2,813,937

GUIDED PUSH ROD MCHANISM Filed-Dec. 2. 1955 3 sheets-Sheet 1 M 'EE- 40.

67 INVENToR.

Tau/4x0 Jaf//v .D/Eacp 4 Tra/6V Nov. 19, 1957 E. J. DIEBOLD GUIDED PUSH Rop MECHANISM 3 Sheets-Sheet 2 Filed Dec. 2. 1955 Nov. 19, 1957 E. .1. DIEBOLD GUIDED PUSH ROD MECHANISM 5 Sheets-Shea?l 3 Filed DSC. 2. 1955 United States Patent GUIDED PUSH ROD MECHANSM Edward John Diebold, Ardmore, Pa., assigner to I-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Application December 2, 1955, Serial No. 550,617

18 Claims. (Cl. 200-30) My invention relates to mechanical rectifiers and more specifically to an operating mechanism for operating the contacts of a mechanical rectifier into and out of engagement.

Mechanical rectiers are used primarily in the conversion of large amounts of power wherein a pair of metallic contact in series with an A.C. power source are opened and closed in synchronism with the input A.C. power frequency to thereby deliver a uni-directional power to a D.C. load which is placed in series with the A.C. power som-ce and the contact. That is, when the contact is closed, current may flow from the A.C. source to the D.C. load. Conversely, when the contact is opened which would be the case when the potential of the A.C. source is in a direction which is opposite to the potential desired for the D.C. load) then the A.C. potential will fall across the open contact and current will not ow to the D.-C. load.

Mechanical rectifiers operating according to these general principles are shown in copending application Serial No. 307,024, filed August 29, 1952.

Operating mechanisms for the contacts used heretofore are constructed to have a push rod which is brought into and out of engagement with a movable bridging contact. More specifically, this push rod is imparted an oscillatory motion in the direction of its axis by means of an oscillating7 link which is oscillated by an eccentric shaft which in turn is driven by a synchronous motor. Hence rotation of the synchronous motor eccentric shaft will oscillate the coaxial oscillating link which has the push rod fastened at one end thereof. This oscillatory motion is imparted to the push rod which is brought into engagement with the bridging contact of the mechanical rectifier to thereby move this contact out of engagement with the stationary contacts.

Subsequent motion of the push rod will then release the engagement between the push rod and the bridging contact to thereby allow closing bias forces operating on the movable contact to move it into engagement with its cooperating stationary contacts.

The above mentioned type of contact actuating mechanism has shown many severe disadvantages. Since the contacts of a mechanical rectifier will operate 216,000 times per hour when rectifying a sixty cycle source, it is obvious that extremely etiicient guiding of the contact is necessary. This fact is substantiated in that experience over many years of operation has shown that the life of mechanical rectifier contacts is materially impaired by poor guiding of the push rods which actuate their operation. In one example, a machine which performed satisfactorily under fully load for more than eight thousand hours without showing extensive contact wear failed after no more than eight hours of operation under similar conditions merely because the guiding of the push rod was not satisfactory.

Poor push rod guiding in the prior art type of mechanisms has been caused by insutiicient length of support of the push rods and too much play between the support and the moving push rod itself. The effect of the poor guiding is that the push rod jumps around during operation and hits the movable contact on different spots every time it operates. This of course imparts a slightly random motion to the contact which makes it sit a little different after each operation. Because the contact surfaces are always slightly rough (due to the passage and interruption of electric current) the random motion displaces these rough spots and creates surface deformations which very soon result in fatigue of material and loose metal particles. The loose metal particles dance around between the contacts and cause a new roughness every time they hit another spot which is then another cause of damage, and so on.

This damage once it has been started, has been shown to progress as an exponential function of time and becomes intolerable after a very short time. This in part explains why a very slight amount of play of the push rod can possibly reduce the contact life by one thousand times.

Another very severe problem in the presently used mechanical rectifier mechanisms is in the shock waves or pressure waves which travel from the push rod of any contact into the actuating mechanisms, the various component parts driving the actuating mechanisms and throughout each of the other contacts of the mechanism.

When the contact is opened, the mechanical drive system knocks the contact open by means of the push rod through the levers or linkages which are actuated by means of the bearings. As a result, the shock force between the various parts, one of which is in motion and the other of which is standing still, amounts to several tons of instantaneous pressure. This pressure wave travels from the push rod into the actuating mechanism, through the actuating mechanism and into the bearings, through the bearings and into the housing of the rectifier mechanism, and from the housing into the push bars and the stationary contacts of the other contacts of the mechanical rectier.

Shock waves have been measured in mechanical rectifiers which have approximately .001 of an inch displacement at a frequency which may be several kilocycles, thereby causing great stresses and unduly high displacement of the members subjected to them.

Hence contacts which must open and close under these shock wave conditions are subjected to still another kind of random motion which has been shown above to be detrimental to the contact life.

As will be shown hereinafter, the operating mechanism of my invention still ailows the contact to be opened suddenly and closed suddenly but the shock wave created thereby will be isolated from the actuating mechanism and will not travel back through the actuating mechanism and into the housing and subsequently to the other contacts of the rectifier.

A further drawback encountered in presently used mechanical rectifier actuating mechanisms is that the bearings used are subjected to short stroke oscillations, thereby resulting in very high wear of the bearings. That is, since the push rod only has to go through a short sine wave type of motion, the bearings which actuate it are subjected to short oscillations or oscillations which are only over a range of a few degrees. It is well known that it is diilicult for roller or needle bearings to operate under such conditions because the rolls or needles are then given the poor property of rolling themselves into the races of the bearings because the lubricating oil is squirted out from under the rolls to thereby allow binding and damage.

In view of this property, which is inherent in short stroke oscillation and shock loads, a very strong lubrication must be used for the bearings. It should be noted, however, that in spite of the strongest lubrication, damage of the bearings frequently occurs. However, the very strong lubrication which is required, imparts a serious drawback to the contact operation. That is, oil which is made to lubricate all of the movable parts of the mechanism can now reach to contact surfaces. The electrical contacts, which then are forced to operate under oily conditions are soon covered with a black tarry substance which has been shown to impair the operation, cause overheating of the contacts, and leads to subsequent contact failures.

'Ihe principle of my invention is to use an actuating mechanism which is essentially an oscillating mass suspended by at least one spring. The oscillating mass is then driven by the eccentric shaft of the synchronous motor and is either suspended or guided or both by the above mentioned suspension spring which guides the oscillating mass for a smooth linear oscillatory motion.

The push rod is then directly fastened to this oscillating mass which will now perform an essentially perfectly guided oscillating motion.

More specifically, the oscillating parts which assume the smooth linear oscillating motion can be directly and metallically fastened to the housing of the machine by means of springs such as flat blade springs. If desired, the spring constant of the suspending springs and the mass of the oscillating body can be adjusted in order to obtain a resonant frequency which is substantially equal to the operation frequency. Therefore, the power required to drive the mechanism will now only have to overcome the friction loss and is not needed to accelerate or decelerate the moving mass.

It is seen therefore that the use of my novel actuating mechanism provides a push rod which is substantially perfectly guided to thereby overcome the guiding problem which is inherent in the prior art actuating mechanism. Furthermore, since the oscillating mass can be connected to the rotating parts of the mechanism through blade springs which absorb not only the side Way motion but also the sudden shock loads, the shock stresses which have been mentioned above as being a serious limitation in the presently used mechanical rectifier actuating mechanisms are now entirely confined to an oscillating mass which is entirely suspended by springs. Since, therefore, the mass is only connected to the rotating parts of the machine by springs, it is clear that the shock vibrations will be confined within this one Isolid part and the shock will not be transferred through the machine housing, bus bars and subsequently to the other contacts of the machine.

It should be further noted that the use of my novel oscillating actuating mechanism will similarly eliminate a great part of the noise which is made in a mechanical rectier due to the shock waves traveling over the surfaces of the housing of the mechanism.

In a similar manner, the bearing problem which was present in the prior art type of actuating mechanism is now overcome in the use of my novel device. That is the only bearings required in my new mechanical rectifier actuating mechanism are the ones supporting the rotary drive shaft and the eccentrics actuating the mechanisms which can comprise a row of bearings along the shaft. Clearly, however, these bearings all rotate over the full arc of a circle and do not have the prior type of oscillatory motion. Therefore, the bearings which are used in the fulfillment of my novel invention are easily lubricated and of course cannot be damaged due to the non-existent short stroke motions.

It is now clear in discussing this phase of the advantages shown by my novel mechanism that the problem of oil which was previously required in the strong lubrication of the bearings will not reach the contacts since this strong lubrication has been now reduced to a minimum' and contact life will accordingly be extended. Similarly, because my moving mass is suspended only by springs, the guiding is achieved without any play whatsoever to thereby eliminate the present problem of additional contact wear due to the play between the push rod and the push rod support.

In summary, therefore, it is seen that the use of my novel actuating mechanism for mechanical rectifier contacts eliminates the essential problems which were present in the previously used mechanism rectifier actuating mechanisms which were poor push rod guiding, play between the push rod and its support, shock waves which were transmitted to the mechanism housing, short stroke oscillations which caused high wear in the bearings, and oil reaching the contact surfaces.

Accordingly, a primary object of my invention is to provide an actuating mechanism for mechanical rectier contacts which comprises a push rod fastened to a suspended oscillating mass, this mass being oscillated by the mechanical rectilier motor.

Another object of my invention is to provide an actuating mechanism for mechanical rectifier contacts which comprises an oscillating mass which is suspended from a stationary housing by means of at least one spring wherein a push rod fastened to this oscillating mass moves in a substantially perfectly guided oscillating motion and play is eliminated between the push rod and the stationary bodies.

Still another object of my invention is to provide a push rod for actuating mechanical rectifier contacts which is suspended by a spring for both support and guiding and is driven in an oscillating motion responsive to the rotation of a synchronous motor.

Still another object of my invention is to provide an oscillating mass for the actuating mechanism of a mechanical rectifier contact which is suspended by at least one spring and the mass and spring constants are so chosen to allow the oscillated mass to be oscillated at its natural resonant frequency.

- A further object of my invention is to provide an actuating mechanism for mechanical rectier contacts wherein all bearings used are rotated through 360 to thereby minimize lubrication requirements and substantially eliminate oil flow to mechanical rectifier contacts.

A still further object of my invention is to provide an actuating mechanism for mechanical rectifier contacts which is so constructed as to be mechanically isolated from the rectifier housing to thereby prevent the transmission of shock waves from the actuating mechanism and into the housing.

These and other objects of my invention will now become apparent from the following description taken in connection with the drawings, 'in which:

Figure l is a schematic electrical diagram of a mechanical rectifier to which my novel actuating mechanism can be applied.

Figure 2 is an exploded perspective view of an actuating mechanism for mechanical rectifiers contacts which is constructed in accordance with my novel invention.

Figure 2a is a detailed view of one possible method for clamping of the springs of Figure 2.

Figure 3 is an exploded perspective view of one portion of 2 which shows the eccentric drive shaft in greater detail.

Figures 4a, 4b and 4c show a motion picture sequence of the operation mechanism such as that of Figure 2.

Figure 5 is a more detailed drawing of a side view of a mechanism of the type shown in Figure 2 as extended to the operation of six mechanical rectifier contacts.

In Figure l, the source of alternating current is derived from the A.C. voltage source which energizes the conductors 10 and passes through the circuit breaker 1l to the transformer 12. Current is subsequently passed through commutating reactor 13 to step the current for commutating purposes as set forth in U. S. Patent No. 2,693,569. The construction of the commutating reactor 13 is described in copending application Serial No. 301,88()

filed July 31, 1952, now Patent No. 2,759,128, dated August 14, 1956.

The current then passes through the disconnect switches 14 to the contact assemblies 15 and 16. The contact assemblies 15 and 16 which are sequentially operated in synchronism with the frequency of the A.C. source (by the novel actuating mechanism of my invention) and then connected to the direct current buses 17 and 18.

Referring now to Figures 2 and 3 which show one example of an actuating mechanism for mechanical rectifier contacts which is constructed in accordance with my vention, a motor 19 is shown which is the synchronous drive motor of the mechanical rectifier unit. The motor 19 rotates a drive shaft 20 which contains an eccentric 21 as shown specifically in Figure 3. As will be shown hereinafter, one eccentric can, if so desired, be used to accommodate two contacts. When a six contact system is used for rectification of a three phase sour-ce it is obvious that the shaft can then contain three eccentrics along its shafts being displaced by 120 from one another.

However, the mechanism shown in Figures 2 and 3 is described herein with reference to only a pair of contacts for purposes of simplicity and accordingly only a single eccentric 21 is shown along the drive shaft 20.

The shaft extends through an aperture 22 of the member 23 as shown in both Figures 2 and 3 and as shown more specifically in Figure 3, the eccentric 21 is positioned to be placed within the bearing 24 whereby member 25 will be oscillated responsive to rotation of the shaft 2G. As shown more specifically in Figure 3, shaft 2t) further extends through a second aperture 26 of member 27 whereby further eccentrics placed on the shaft 20 may be inserted within other members similar to the member for the operation of other pairs of contacts.

The oscillating mass can now be seen with reference to Figure 2 as comprising the members 23, 25 and 27. Members 23 and 27 are shown as being clamped together by means of the plate- like members 28 and 29 through the medium of a fastening means which could be screws 30 and 31.

A spring means is then provided and is shown herein as comprising the fiat springs 32 and 33. Flat springs 32 and 33 are attached to the plates 28 and 29 by clamping bars 34 and 35, respectively, and the corresponding screw means.

Apertures or slots 40 and 41 are provided in the spring member 32 and apertures 42 and 43 are provided in the spring member 33 to thereby form a member which is rigid in a plane parallel to its surface and flexible in a plane perpendicular to its surface.

Clearly there are many ways of providing an oscillating mass of this nature and the particular structure described herein is merely illustrative of one of those many ways.

A stationary body is shown as comprising the posts 44,

45, 46, 47. Clearly this is merely to indicate that a sta- 's tionary housing or a body which is stationary with respect to the oscillating mass is present for purposes of suspending the oscillating mass. The suspension of the oscillating mass is then accomplished in Figure 2 in laccordance with the principle of my invention by means of the two fiat springs 48 and 49 respectively, which are fastened in some manner to the stationary support of the unit. For illustrative purposes only, the spring members 48 and 49 are shown herein as being clamped to the relatively stationary posts 44 and 45, and 46 and 47 by the clamping bars 44a, 45a, 46a and 47a, respectively.

It is to be noted that both of these suspending spring members 48 and 49 are provided with apertures 50 and 5l and 52 and 53. Here again the apertures now provide a spring which is extremely flexible in la direction perpendicular to its plane and yet rigid in a direction parallel to its plane.

Similarly, the spring is so shaped that it is wide where high stresses are encountered and narrow where low stress 6 is encountered whereby the flexibility of the narrow sections relieves stresses in the wide sections.

In order to assure dependable operation of the springs 32, 33 and 48, 49, the clamping of the springs is done very carefully. The springs are made of flat spring steel clamped over their full width by means of the clamping bars and if desired, by clamping plates. As specifically shown in Figure 2a, the spring 32 is clamped at all points by the interposed clamping plates 34a which, by extending beyond the clamping edge of the clamping bars 34, effect a more gentle fastening. Hence, spring breakage due to clamping stresses is substantially eliminated.

The suspension of the oscillating mass by means of the springs 48 and 49 can then be accomplished by means of post 54 which is fastened in any desirable manner to the plate 23 and a similar post which cannot be seen in Figure 2 which is fastened to the plate 29.

These posts 54 can then be provided with an extension such as the threaded extension 55 which cooperates with holes 56 and 57 of springs 48 and 49, respectively. In order to maintain the post 54 to the spring 49 and similarly to maintain the post of the plate 29 to the spring 48, nuts such as 58 and 59 are provided which will cooperate with the threaded extension 55 t0 thereby maintain the post 54 to the spring 49 and similarly maintain the post of the plate 29 to the spring 48.

It is to be emphasized that the fastening method as described herein is merely illustrative of many desirable methods. To continue this example, it is seen that the push rods 60 and 61 which could be made to cooperate with the portion of the threaded extension 55 which extends past the nut 58 Vare then fastened to the oscillating mass. It is now seen that when an oscillating motion is imparted to the push rods 60 and 61, the movable contacts shown schematically as contacts 62 and 63 can be made to move into and out of engagement with the A.C. bus 64 and D.C. bus 65 and A.C. bus 66 and D.C. bus 67 respectively against the action of the closing bias springs 68 and 60 respectively. Contact structures of this type may be seen in more detail in copending application Serial No. 307,067 filed August 29, 1956.

That is to say that oscillation of the push rod 61 will first bring it into engagement with the movable contact 69. Continued motion of the push rod 61 will then force the contact 63 to move against the action of its closing bias 69 to thereby separate the A.C. bus 66 from the D.C. bus 67 and interrupt the fiow of current between the A.C. source and the D.C. load. Upon oscillation of the push rod 61 in the opposite direction, it is clear that the bias spring 69 will move the movable contact 63 into a bridging engaged position with the AfC. bus 66 and D.C. bus 67 to thereby effectively connect an A.C. source to a D.C. load for energization thereof.

The operation of the system shown in Figures 2 and 3 will now be apparent since it is clear that rotation of the shaft Ztl will oscillate the member 25 in View of the eccentric 21 shown in Figure 3. This eccentric motion will then be imparted to the complete oscillating mass which comprises the members 23, 27, 28, 29, 32 and 33. rfhis oscillating motion will, in view of the stationary guide springs 4S and 49, drive the oscillating mass and hence the push rods 60 and 61 in a linear or straight line motion. Obviously, the springs 32 and 33 Will merely flex, depending upon the position of the eccentric 21 to thereby absorb any stresses which might be provided in the system and the oscillating mass is completely guided only by the springs 4S and 49.

For a clearer understanding of the operation of the device shown in Figures 2 and 3, a top view of the device of Figure 2 is shown in Figures 4a, 4b and 4c. In these figures the vertical drive shaft 2f) carries the eccentric 21 which is positioned within the bearing 24 for oscillating the member 25. However, whereas Figure 2 shows the stationary circuit of the spring members 4S and 49 as being the four posts 44, 45, 46 and 47, Figures 4a, 4b and 4c show this support as comprising a first stationary body 7 0, and a second stationary body 71 where the spring 48 is fastened between boxes 70 and 71 by means of the screws 72 and 73 and the spring 49 is similarly fastened by means of the screws 74 and 75. For the sake of simplicity only the operation of the right hand contact is described although a contact could be shown as being operated by the push rod 60 as well as push rod 61.

It is now clearly understood with reference to Figure 4 that rotation of the shaft 20 about its iixed axis will drive the eccentric 21 which in turn will affect the member 25 through the bearing 24 to transmit a force through the springs 32 and 33 to subsequently cause a linear oscillation of the push rods 60 and 61 which are suspended from the stationary housing by means of the springs 48 and 49. This oscillation will be in the direction given by the double arrow indicated by the number 76. As the eccentric is moved up and down with respect to the figure, it is clear that the force imparted to the springs 32 and 33 will be in a directional proportional to their plane and the springs will therefore iieX to thereby absorb this energy.

Referring now to Figure 4c, the position shown is that of the contact engaged position, the push rod 61 being completely removed from the movable contact 63. In this position, it is seen that the springs 48 and 49 are exed to their maximum left hand position and that the springs 32, 33 are unilexed.

As the shaft 22 is rotated (by the synchronous motor which is not shown here) in a clockwise direction, it is seen that the mechanism will move from the position of Figure 4a to that of Figure 4b. In this motion, the eccentric 21 will drive the push rod 61 to engage the movable contact 63 through the mechanical connection comprising the eccentric 21, member 21, springs 32, 33, plate 28 and the push rod 61. It is further seen in Figure 4b that the springs 4S, 49 have moved from their leftwardly deected position to a straight position and that the springs 32, 33 have deflected upward due to the upward motion of the eccentric 21.

Further rotation of shaft 22, by its driving means, will subsequently move the oscillatory mass to its extreme right hand position of Figure 4c to cause subsequent disengagement of movable Contact 63 from its cooperating contacts 66, 67 by means of the push rod 61. It is seen that the springs 43 and 49 are deiiected to their extreme right hand position and that the springs 32 and 33 are undeflected since the eccentric 21 is in a central position.

Hence the advantages presented by the use of my novel actuating mechanism are now apparent when referring to Figures 2, 3, 4a, 4b and 4c.

Clearly, the shock vibration which is due to the impingement of push rods 60 or 61 upon the movable contacts 62 or 63 respectively will be transmitted through the push rod 60 and 61 and into the oscillating mass which is represented in Figure 2 by the members 23, 25, 27, 28, 29, 32 and 33.

This shock however, will not be transmitted to the stationary supports shown as support members 44, 45, 46 and 47 in Figure 2 and as members 79 and 71 in Figures 4a, 4b and 4c. That is to say, that by suspending the oscillating mass on springs 43 and 49 the mechanical shock and vibration will be isolated to the isolating mass since the springs 4S and 49 cannot transmit this shock to their stationary supports.

Furthermore, reference to the operation of the mechanism of Figs. 4a, 4b and 4c has shown that the oscillating mass will oscillate only in the direction shown by the arrow 76. Since the push rods are directly attached to this oscillating mass, it is clear that they will be perfectly guided in a linear oscillating motion and the point at which the push rods 6G and 61 of Figure 2 impinge upon the movable contacts 62 and 63 will not vary.

As a further advantage, it is seeni that the bearings 24 of Figures 4a, 4b and 4c do not perform a short stroke type of oscillation but rather perform-acontinuous rotating motion to Vwhich bearing operation.A is

best adapted. y 5

Hence, lubrication of the bearings may now be Vat ay safe minimum and the lubricating oil of the bearings is substantially isolated from the contact surfaces. As a further advantage of the actuating mechanism shown in Figures 2, 4a, 4b and 4c, it is clear that the size of the driving motor may be decreased if the mass of the oscillating body and the spring constant of the springs 48 and 49 is so chosen as to be resonant with the desired oscillatv ing frequency, thereby requiring that only frictional forces be overcome.

Although in the foregoing I have described my novel actuating mechanism in conjunction with a mechanism for driving a pair of contacts such as the movable contacts 62 and 63 of Figure 2, it is clear that this mechanism could be utilized for the operation of only one contact or a plurality of contacts.

Similarly, my invention hasy been described in conjunction with a motordrive. However, the motor driving system could clearly be replaced by a system for'driving a spring suspended oscillatory mass which couldbe actuated by electromagnetic, pneumatic, hydraulic or anyl other system.

As an obvious extension, it is equally clear that my novel actuating mechanism can be extended to drive the six contacts of a six contact mechanical rectifier wherein each pair of contacts are 120 displaced in their mechanical operation. This embodiment is shown in Figure 5 wherein six contacts are driven from what is essentially three mechanisms of the type shown in Figure 2 where the view is taken from the front of Figure 2.

As shown in Figure 5, six push rods extend in a plane parallel to a plane containing the drive shaft 80. As shown, the first three push rods 81, S2, and 83 extend to the left of the drive shaft axis and push rods 84, 85 and 86 extend to the right hand side of the drive shaft axis. A contact structure has been shown in conjunction with the push rod 82 and is shown generally at 87. Although each of the other push rods 81 through 86 will have similar contacts associated with them, they are not shown here in order to simplify the drawing.

lt is now seen that the drive shaft 30 is supported by the main bearing S8 and is guided by the bearings 89 and 9i) and bears the eccentrics 91, 92 and 93.

These eccentrics are surrounded by the bearings 94, and 96 which are standard roller bearings each of which being surrounded by a member 97, 98 and 99, the members 97, 98 and 99 serving the function which was served by the member 2S of Figure 2.

In order to obtain the 120 phase shift between each pair of six contacts, it is clear that the eccentrics 91, 92 and 93 are mechanically offset by 120. Referring now to the mechanism for actuating the lowest pair of contacts, the spring 100 is clearly seen, this spring being similar to the spring 33 of Figure 2. Hence, in the rotation of the eccentric 93, a force is transmitted to the spring 190 and from this spring to the supporting springs shown in cross section as springs 101 and 102. Gbviously, the springs 191 and 192 correspond to the supporting springs 48 and 49 of Figure 2.

The means whereby the springs 101 and 192 are fastened to the oscillating mass is clearly shown in the upper oscillating mechanism of Figure 5 which oscillates the push rods S1 and 34 and comprises the bolt means shown as bolts 1133, 104, 105 and 106. Therefore, upon rotation of the shaft S0 by means of a synchronous motor which is not shown here, the pair of push rods 81 and 84 will be imparted a linear oscillating motion by the eccentric 91.

In order to further isolate the contact from .oil and dust, 'each push rod is provided with a rubber sleeve which is oil and dust tight, such as the rubber sleeve 120 seen in conjunction with push rod 81.

The return spring 121 is then supported between the stationary housing 122 and a member 123 which is fastened to the push rod 81, this return spring serving to maintain its push rod assembly in engagement with its associated eccentric.

Hence, when the middle structure is moved to the left it is seen that the push rod 81 would actuate the operation of its contact shown generally at 87. This contact generally comprises a movable contact 107 which is movable into and out of engagement with the stationary contacts 108 and 109. Details of this typed contact structure and the bus arrangement may be had with reference to copending application.

If further guiding of the movable contact is desired, a guide spring such as the spring 110 which is clearly described in'copending application Serial No. 438,465 led June 22, 1954, can be fastened to the movable contact.

Hence when the shaft 80 is rotated by a synchronous motor which is not shown, the middle mechanism of Figure 5, which is suspended for oscillation by means of the springs 101 and 102 as shown in the upper mechanism of Figure will bring the push rod 82 into engagement with the movable contact 107 to thereby drive the contact against its biasing springs 111 and 112 to effect contact disengagement. As the rotation of shaft 80 continues, it is clear that the oscillation of the movable mass will be in the right hand direction and the push rod 82 will thereby release the movable contact 107 and allow the bias springs 111 and 112 to bring the movable contact 107 in`to engagement with the stationary contacts 108 and 109, one of which would be fastened to the D. C. sideof-a-load and the other being fastened to the A. C. side of a load.

By now proceeding in'this manner, it is clear that contacts on the left :hand side of Figure 5 will 'be driven -into and out vof engagement according to a phase displacement of 120 to thereby allow effective rectification of a three phase A. C. source wherein each of the contacts is-connected between oneof the phases and one potential of the D.C. load. Similarly, the push rods 84 and-85 and 86, shown to the right of Figure y5 will `achieve contact rectification with 120 phase displacement from each other and 180 from its opposite contact for connecting thesame three phases of the A.C.-source tothe opposite potential of the D.-C. load.

Hence it is seen that in a six contactmechanical rectifier, my novel invention can be applied wherein a first, second and third oscillatable mass are provided being driven by the eccentrics 91, 92, and 93 respectively from the shaft 80 of the mechanical rectifier motor. Clearly each of these masses is suspended bymeansfof the relatively strong springs 101 and 102 to thereby impart eX- tremely -eficient guiding of each of the associated push rods 81 through'86.

It lis further seen that in View of the'rigid connection between the oscillatable body and the push rods, that there will be no play between the push rod and the stationary structure. Similarly, since the bearings 88, 94, 95 and 96 rotate through a 'complete 360 cycle lubrication need be only at a minimum. Hence, excess oil which will not befpresentwill not in any way be able to eventually contaminate the contact surfaces such as the surfaces between the movable contact 107 and the stationary coutacts 108 and 109.

In order 'to decrease the size of the motor, it is clear that the mass ofthe moving parts and the strength of the springs can be adjusted to have its natural resonant frequency at the oscillating frequency .of the rectifying system.

Although I have described preferred embodiments of my invention, it will now be `.evident that many modii 10 cations and Variations may be made by those skilled in the art. I therefore prefer to be limited, not by the specific disclosure herein, but only by the appended claims.

I claim:

1. A mechanism for operating a pair of cooperable contacts into and out of engagement, said contacts being biased to the engaged position; said mechanism including a synchronous motor having an output eccentric shaft, a push rod, supporting spring means and a relatively stationary body for supporting at least a portion of said supporting spring means; said eccentric shaft being operatively lconnected to said push rod to impart linear oscillatory motion to said push rod responsive to rotational motion of said eccentric shaft; a portion of said push rod being positioned to'engage one of said pair of cooperable contacts when moved in a first direction along its oscillatory path to effect contact disengagement between said cooperable contacts, said push rod being operatively connected to said supporting spring means; said supporting spring means being constructed to isolate mechanical shock due to the engagement of said push rod and said one contact of said pair of cooperable contacts from at least said relatively stationary body.

2. A mechanism for operating a pair of cooperable contacts into and out of engagement, said contacts being biased to the engaged position; said mechanism including a synchronous motor having an output eccentric shaft, a push rod, supporting spring means and a relatively stationary body for supporting at least a portion of said supporting spring means; said eccentric shaft being operatively connected to said push rod to impart linear oscillatory motion to said push rod responsive to rotational motion of said eccentric shaft; a portion of said push rod being positioned to engage one of said pairs of cooperable contacts when moved in a first direction along its oscillatory path to effect contact disengagement between said cooperable contacts, said push rod being operatively connected to said supporting spring means; said supporting spring means being constructed to be flexible in the direction of said oscillatory motion of said push rod, said supporting spring means thereby being guided in its direction of oscillatory motion.

3. A mechanism for -operating a'pair of cooperable contacts into and out of engagement, said contacts being biased to the-engaged position; said mechanism including a synchronous motor having an output eccentric shaft, a push rod, -a supporting-spring means and a relatively stationary body for supporting said supporting spring means; said eccentric shaft being operatively connected to said push rod t-o impart linear oscillatory motion to said push rod responsive to rotational motion of said eccentric shaft; said operative connection between said push rod and said eccentric shaft including a bearing surface, the relative rotation between said eccentric shaft and said push rod at said bearing surface being 360; a portion of said push rod being positioned to engage one of said pair of cooperable contacts when moved in a first direction along its oscillatory path to effect contact disengagement between said cooperable contacts, said push rod being operatively connected to said supporting spring means; said supporting spring means being constructed to isolate mechanical shock due to the engagement of said push rod and lsaid one of said pair of cooperable contacts from at least said relatively stationary body.

4. A mechanism for operating a pair of cooperable contacts into :and out of engagement, said contacts being biased to the engaged position; said mechanism including a synchronous motor having an output eccentric shaft, a push rod, a'supporting spring means and a relatively stationary body for supporting said spring means; said eccentric shaft being operatively connected to said push rod to impart linear oscillatory Vmotion to said push rod responsive to rotational motion .of said eccentric shaft;.said

"11 operative connection betweenusaid push-rodwand said eccentric shaft including a bearing surface, thev relative rotation between said eccentric shaft and said'push'rod' at said bearing surface being 360, bearing lubrication and wear being minimized by the rotation of the bearings over a full 360 cycle; `a portion kof said push rod being positioned to engage one of said pairs of cooperable contacts when moved in a rst direction along its oscillatory path to effect contact disengagement between said cooperable contacts, said push rod being operatively connected to said supporting spring means; said supporting spring means being constructed to be flexible in the direction of said oscillatory motion of said push rod, said spring thereby being guided in its direction of oscillatorymotion. Y i

5. In a mechanism for operating a movable contact into and out of engagement with a fixed contact; said mechanism including a synchronous motor for driving an eccentric shaft, an oscillating mass. and a spring means for supporting said oscillating mass from a relatively stationary support; said eccentric shaft being operatively connected to lsaid oscillating mass to impart linear oscillatory motion to said oscillating mass responsive to rotary motion of said eccentric shaft; said oscillating mass being positioned to engage said movable contact Vand move said movable contact out of engagement with said fixed contact when moved in a first direction; biasing means for said movable contact; said biasing means being constructed to move said contact to its engaged position when said oscillating mass is moved in a direction opposite said first direction.

6. In a mechanism for operating a movable contact into and out of engagement with a fixed contact; said mechanism including a synchronous motor for driving an eccentric shaft, an oscillating mass and a spring means for supporting said oscillating rnass from a relatively stationary support; said eccentric shaft being operatively connected to said oscillating mass to impart linear oscillatory motion to said oscillating mass. responsive to rotary motion of said eccentric shaft; ysaid oscillating mass being positioned to engage said movable contact and move said movable contact out of engagement with said fixed contact when moved in a first direction; biasing means for said movable contact; said oscillating mass being moved out of engagement with said movable contact when said `oscillating mass is moved in a direction opposite said first direction, said movable contact being moved to the engaged position by said biasing means.

7. In a mechanism for synchronously operating a movable contact into and out of engagement with a fixed contact; said mechanism including a synchronous motor for driving an eccentric shaft, an oscillating mass and a spring means for supporting said oscillating mass from a relatively stationary support; said eccentric shaft being operatively connected to said oscillating mass to impart linear oscillatory motion to said oscillating mass responsive to rotary motion of said eccentric shaft; said oscillating mass being positioned to engage said movable contact and move said movable contact out of engagement with said fixed contact when moved in a first direction; biasing means for said movable contact; said biasing means being constructed to move said contact to its engaged position when said oscillating mass is moved in a direction opposite said first direction; the mass of said oscillating mass and the spring constant of said supporting spring having valves to place the resonant oscillating frequency of said oscillating mass at the frequency at which said movable contact is moved into and out of engagement with said fixed contact.

8. A mechanism for synchronously operating a movable contact into and out of engagement with a fixed contact; said movable contact being movable between an engaged and disengaged position with respect to said fixed contact; said mechanismincluding a motor having an output eccentric shaft, a first spring, and a push rod; said first spring being constructed to support said push rod from a relatively stationary support whereby said push rod is linearly movable with respect to said relatively stationary body in a first and second direction; said push rod being positioned to move said movable contact to the engaged position responsive to linear motion thereof in said first direction, said movable contact being moved to said disengaged position responsive to motion of said push rodin said second direction; said motor output eccentric shaft being operatively connected to said push rod; said operative connection being constructed to impart said linear oscillating motion to said push rod responsive to the rotary motion of said output eccentric shaft.

9. A mechanism for synchronously operating a movable contact into and out of engagement with a fixed contact; said movable contact being movable between an engaged and disengaged position with respect to said fixed contact; said mechanism including a motor having an `output eccentric shaft, a first spring, a second spring, and a push rod; said first spring being constructed to support said push rod from a relatively stationary support whereby said push rod is linearly movable with respect to said relatively stationary body in a rst and second direction; said push rod being positioned to move said movable contact to the engaged position responsive to linear motion thereof in said first direction, said movable contact being moved to said disengaged position responsive to motion of said push rod in said second direction; said motor output eccentric shaft being operatively connected to said push rod; said operative connection being constructed to impart said linear oscillating motion to said push rod responsive to the rotary motion of said output eccentric shaft; said second spring being included in said operative connection between said eccentric shaft and said push rod whereby rotary motion of said eccentric shaft imparts linear oscillating force for said push rod to said second spring in a direction substantially perpendicular to the direction :of maximum flexibility of said second spring.

l0. A mechanism for synchronously operating a movable contact into and out of engagement with a fixed contact; said movable contact being movable between an engaged and disengaged position with respect to said fixed contact; said mechanism including a motor having an output eccentric shaft; a first spring, a second spring and a push rod; said first spring being constructed to support said push rod from a relatively stationary support whereby said push rod is linearly movable with respect to said relatively stationary body in a first and second dierction; said push rod being positioned to move said movable contact to the engaged position responsive to linear motion thereof in said first direction, said movable contact being moved to said disengaged position responsive to motion of said push rod in said second direction; said second spring being constructed to operatively connect said push rod to said eccentric shaft, the direction of exing of saidv first spring being substantially perpendicular to the direction of flexing of said second spring; the connection between said second spring and said eccentric shaft being constructed to transmit a linear oscillating motion to said push rod responsive to the rotary-motion of said eccentric shaft.

11. A mechanism for synchronously operating a movable contact into and out of engagement with a fixed contact; said movable contact being movable between an:

engaged and disengaged position withV respect to said fixed Contact; said mechanism including a motor having an output eccentric shaft, a first spring, a second spring and a push rod; said rst spring being so constructed to support said push rod from a relatively stationary support whereby said push rod is linearly movable With respect to said relatively stationary body in a first and second'direction; said push rod being positioned to move said movable contact tothe engaged position responsive' to linear motion thereof in said first direction, said movable contact being moved to said disengaged position responsive to motion of said push rod in said second direction; said second spring being constructed to operatively connect said push rod to said eccentric shaft, the connection between said second spring and said eccentric shaft being constructed to transmit a linear oscillating motion to said push rod responsive to the rotary motion of said eccentric shaft.

12. A mechanism for synchronously operating a movable Contact into and out of engagement with a fixed contact; said movable contact being movable between an engaged and a disengaged position with respect to said fixed contact; said mechanism including a motor, having an output eccentric shaft, a push rod and a spring means; said spring means being constructed to support said push rod for linear oscillating motion and to operatively connect said output eccentric shaft to said push rod; the operative connection between said push rod and said eccentric shaft being constructed to transmit linear oscillating motion to said push rod responsive to rotary motion of said eccentric shaft; said push rod being positioned to move said movable contact to the engaged position responsive to linear motion thereof in said first direction, said movable contact being moved to said disengaged position responsive to motion of said push rod in said second direction.

13. A mechanism for synchronously operating a movable contact into and out of engagement with a fixed contact; said movable contact being movable between an engaged and a disengaged position with respect to said fixed contact, said mechanism including a motor having an output eccentric shaft, an oscillating mass and a first and second spring means; said first spring means being constructed to operatively support said oscillating mass from a relatively stationary body for linear osciliating motion, said second spring means being constructed to operatively connect said output eccentric shaft to said oscillating mass; the operative connection between said oscillating mass and said eccentric shaft being constructed to transmit linear oscillating motion to said oscillating mass responsive to rotary motion of said eccentric shaft; said oscillating mass being positioned to move said moveable contact to the engaged position responsive to linear motion thereof in said nrst direction, said movable contact being moved to said disengaged position responsive to motion of said oscillating mass in said second direction; the resonant frequency determined by the mass of said oscillating mass and the spring constant of said first spring means being substantially that of the oscillating frequency of said oscillating mass.

14. A mechanism for synchronously operating a tnovable contact into and out of engagement with a contact; said movable contact being movable between an engaged and a disengaged position with respect to said fixed contact; said mechanism including a motor having an output eccentric shaft, an oscillating mass and a first and second spring means; said first spring means being constructed to operatively support said oscillating mass from a relatively stationary body for linear oscillating motion, said second spring means being constructed to operatively connect said output eccentric shaft to oscillating mass; the operative connection between said oscillating mass and said eccentric shaft being constructed to transmit linear oscillating motion to said oscillating mass responsive to rotary motion of said eccentric shaft; said oscillating mass being positioned to move said movable contact to the engaged position responsive to linear motion thereof in said first direction, said movable contact being moved to said disengaged position responsive to motion of said oscillating mass in said second direction; the operative support of said oscillating mass from said stationary body by said spring means being incapable of transmitting shock waves between said oscillating mass and said stationary body.

15. A mechanism for synchronously operating a novable contact into and out of engagement with a fixed contact; said movable contact being movable between an engaged and a disengaged position with respect to said fixed contact, said mechanism including a motor having an output eccentric shaft, an osciilating mass and a first and second spring means; said first spring means being constructed to operatively support said oscillating mass from a relatively stationary body for linear oscillating motion, said second spring means being constructed to operatively connect said output eccentric shaft to oscillating mass; the operative connection between said oscillating mass and said eccentric shaft being constructed to transmit linear oscillating motion to said oscillating mass responsive to rotary motion of said eccentric shaft; the operative connection between said eccentric shaft and said oscillating mass being a bearing assembly, the rotating elements of said bearing assembly being rotated through 360; said oscillating mass being positioned to move said movable contact to the engaged position responsive to linear motion thereof in seid first direction, said movable Contact being moved to said disengaged position responsive to motion of said oscillating mass in said second direction.

16. A mechanism for synchronously operating a movable Contact into and out of engagement with a fixed contact; said movable contact being movable between an engaged and a disengaged position with respect to said fixed contact; said mechanism including a motor having an output eccentric shaft, an oscillating mass and a first, second, third and fourth leaf spring; said first and second leaf spring lying in parallel planes and constructed to support said oscillating mass at a first and second point from a relatively stationary body for linear oscillating motion; said third and fourth leaf springs lying in parallel planes and constructed to operatively connect said output eccentric shaft to a third and fourth point on said oscillating mass; the operative connection between said oscillating mass and said eccentric shaft being constructed to transmit linear oscillating motion to said oscillating mass responsive to rotary motion of said eccentric shaft; said oscillating mass being positioned to move said movable contact to the engaged position responsive to linear motion thereof in said first direction, said movable contact being moved to said disengaged position responsive to motion of said oscillating mass in said second direction; the direction of flexing of said third and fourth leaf springs being parallel to the direction of linear motion of said oscillating mass, shock waves thereby being incapable of transmission between said stationary body and said oscillating mass; the planes of said first and second leaf springs being substantially perpendicular to the planes of said third and fourth leaf springs, the direction of fiexing of said third and fourth leaf springs being perpendicular to the linear motion performed by said oscillating mass.

17. A mechanism for operating a pair of cooperable contacts into and out of engagement, said contacts being biased to the engaged position; said mechanism including a driving means, a push rod, supporting spring means and a relatively stationary body for supporting said supporting spring means; said driving means being operatively connected to said push rod to impart linear oscillatory motion to said push rod; a portion of said push rod being positioned to engage one of said pair o-f cooperable contacts when moved in a first direction along its oscillatory path to effect contact disengagement between said cooperable contacts, said push rod being operatively connected to said supporting spring means; said supporting spring means being constructed to isolate mechanical shock due to the engagement of said push rod and said one of said pair of cooperable contacts from at least said relatively stationary body.

18. A mechanism for synchronously operating a movable contact into and out of engagement with a fixed contact; said movable contact being movable between an en- 15 gaged and disengaged position with respect to said fixed contact; said mechanism including driving means, a rst spring, a second spring and a push rod; said first spring being constructed to support said push rod from a relatively stationary support whereby said push rod is linearly movable with respect to said relatively stationary body in a rst and second direction; said push rod being positioned to move said movable contact to the engaged position responsive to linear motion thereof in said rst direction, said movable contact being moved to said disengaged position responsive to motion of said push rod in said second direction; said driving means being operatively connected to said push rod; said operative connection being constructed to impart said linear oscillating motion to said push rod; said second spring being included in said op- References Cited in the le of this patent UNITED STATES PATENTS 2,040,106 Rose May l2, 1936 2,246,922 Macchioni June' 24, 1941 2,310,792 Koppelmann et a1 Feb. 9, 1943 2,666,102 Koppelmann Jan. l2, 1954

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