US2285890A - Stationary contact - Google Patents

Description

June 9, 1942. H, G, BLQS SER 2,285,890

STATIONARY CONTACT Filed Nov. 16, 1939 6 Sheets-Sheet 3 10 50 4.9 10 INVENTO Henman .filosse HIS ATITORNEY June 9,1942; H. G. BLOSSER 5 0 STATIONARY CONTACT Filed Nov. 16, 1939 e Sheets-Sheet s INVENTOR Henm .Blossen F257. 8. BY

HIS ATTORNEY June 9, 1942. H. e. BLOSSER STATIONARY CONTACT Filed Nov. 16, 1939 6 Sheets-Sheet 6 INVEINTOR Fly 9.. Y

P1726! .fllossez BY 2 C H15 ATZI'ORNEY Patented June 9, 1942 STATIONARY CONTACT Herman G. Blosser, Pittsburgh, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application November 16, 1939, Serial No. 304,811

(01. Min-166) 3 Claims.

My invention relates to electrical relays, and particularly to electrical relays which are suitable for use in railway signaling systems employing for the control of signaling devices direct current which is periodically interrupted or coded at different frequencies in accordance with trafiic conditions.

In signaling systems of the type referred to at least three different types of relays are employed, namely, code transmitters for periodically interrupting the direct current at the desired frequency, code following relays which respond to coded current of one polarity only, and neutral relays which respond to the presence or absence of direct current whether it is coded or uncoded.

One object of my present invention is to provide a relay of such construction that it can be converted into any one of the three types above described by making certain relatively minor changes.

Another object of my invention is to provide a relay construction which is simple, rugged and can be manufactured at a minimum cost.

Other objects and characteristic features of my invention will become apparent as the description proceeds.

In, the accompanying drawings, Fig. 1 is a top plan view showing one form of relay embodying my invention. Fig. 2 is a side elevational view of the relay shown in Fig. l, certain of the case parts being broken away or sectioned to better illustrate the construction of the remaining parts. Figs. 3, 4 and 5 are detail sectional views taken substantially on the lines III-III, IV--IV, and VV, respectively, of Fig. 1. Fig. 6 is a wiring diagram for the relay shown in Fig. 1. Fig. '7 is a detail view of one of the brackets 26 forming part of the relay illustrated in the preceding views. Fig. 8 is a view similar to Fig. 3 showing a modification of the relay illustrated in Figs. 1, 2 and 3. Fig. 9 is a left-hand side view of the relay shown in Fig. 8 with certain of the parts broken away or removed to better illustrate the remaining parts. Fig. 10 is a detail sectional View showing a further modification of the relay illustrated in Figs. 1, 2 and 3.

Similar reference characters refer to similar parts in each of the several views.

Referring first to Figs. 1, 2 and 3, the relay in the form here shown comprises a suitable case, consisting of a top plate I of insulated material secured to the upper end of a non-magnetic frame 2, a metal base plate 3 secured to the lower end of the frame 2, and a transparent glass cylinder 4 clamped between the top plate I and the base plate 3. The main or upper part of the frame 2 is formed from a single piece of material bent generally into an inverted U-shape, and comprises two vertically disposed plate portions 2a and 2b of substantially trapezoidal form terminating at their upper ends in spaced parallel arms 20 which form openings 2d. through which certain portions of the contact mechanism of the relay can be viewed for inspection. A horizontal bar 6 is secured to the lower end of each plate portion 2a and 21) by means of studs I, and extending between the bars Ii at their opposite ends are spacing rods 8 held in place by studs 9. These latter studs extend through clearance holes in the plate portions 2a and 2b and the bar 6, and are screwed into tapped holes formed in the ends of the spacing rods, as will readily be apparent from an inspection of the drawings. The base plate 3 is secured to the frame 2 by means of screws I0 screwed into tapped holes I I provided in the bars 8. It will be seen, therefore, that the frame provides a rigid support for the various case parts. A gasket I2 of cork or other suitable material is interposed between the top plate I and. the upper end of the cylinder 4, and a similar gasket I3 is interposed between the bottom plate and the lower end. of the cylinder, thereby sealing the case against the entry of dirt or other foreign substances.

A contact carrying rocker I5 of suitable insulating material is suspended from the top plate I for swinging movement between two extreme positions by means of two flexible strips I6 and I"! (see Figs. 3 and 4), and this rocker is provided with a plurality of flexible contact fingers I8 and I9, each of which cooperates with a fixed contact member IM or I9a to close a contact I8I8a or Iii-49a according as the rocker is swung to one or the other of its extreme positions. The contact fingers I8 and I9 are disposed in pairs and are secured to the opposite sides of the rocker within suitable vertical grooves which maintain the fingers in the desired vertical positions, by means of studs 20 moulded into the rocker and provided at each end with a nut 2|. The two studs 20 which secure the two end pairs of fingers I8 and I9 to the rocker also serve to secure the lower ends of the strips I6 and IT to the rocker, and disposed between each strip I6 or I! and the adjacent finger I8 is a spacing block 22 of such thickness that the lower ends of the strips I6 and H are disposed substantially at the center of the rocker. A terminal post 23 is mounted in the top plate directly above each pair of fingers I8 and I9 and the upper ends of the strips I6 and I! are secured to the heads of the two outer terminal posts 23 by means of rivets Ida and clamping blocks I4. It will be seen, therefore, that the strips I6 and I1 not only serve to support the rocker, but also serve to electrically connect the two outer pairs of fingers with the associated terminal posts. The remaining two pairs of fingers are electrically connected with the vertically aligned terminal posts 23 by means of flexible connectors 24. The positions of the fiexible fingers when the fingers are out of engagement with the associated fixed contact member are determined by stops which are clamped against the outer faces of the fingers by means of the associated studs 29, and which are so adjusted by bending them that the fingers will break the contacts in the desired positions in response to swinging movement of the contact carrying rocker it.

When the relay is in operation, the rocker is oscillated between its two extremepositions at a relatively rapid rate, and in order to prevent breakage of the strips it and I7 due to the resultant fiexing of the strips, the lower edges of the clamping blocks It on the sides next to the strips and the opposite lower edges of the heads of the associated terminal posts 23 are rounded as shown in the drawings in such manner that any fiexing of the strips which occurs adjacent these parts will be in theform of a gradual curve,

Furthermore, the upper edges of the spacing blocks 22 on the sides next to the strips and the opposite edges of the tops of the slots in the rocker are likewise rounded to prevent sharp bends in the strips adjacent these parts.

The fixed contact members Ito and 13b are all alike, and each comprises a low resistance contact button welded to or formed on one end of an adjusting screw. Each adjusting screw is screwed through the depending vertical leg 25a of an angle bracket 26, the horizontal leg 26b of which is formed with a split portion which re ceives the circular lower end of an associated terminal post 2'! with sufficient clearance to enable the bracket to be moved freely along the post in an axial direction, and also to be rotated to any desired angular position relative to the post. Aclamping screw 28 is associated withthe split portion of each angle bracket and is effective when tightened to clamp the bracket in any position to which it is moved on the associated terminal post. To facilitate turning the adjusting screw, the head of the screw is made polygonal in shape for the reception of a wrench or other suitable tool, and in order to lockthe screw in its adjusted position a lock nut 29 is provided on the outer end of the screw. With this artacts l8--I3a and lt-I9a are all open, and the parts are so proportioned that when the armature occupies the position to which it is biased by gravity, it will be disposed outside of the field set up between the pole pieces 30a and 35b. The length of the armature is such that it is free to swing between the pole pieces, and it will be seen therefore that energization of the winding 33 will tend to pull the armature between the pole pieces, and hence will swing the rocker l 5 in a clockwise direction, as viewed in Fig. 3.

The supply of energy to the winding 33 is controlled by two driving contacts comprising two contact fingers (iii and M (see Fig, 5) which cooperate with fixed contact members tea and a,

respectively. The fingers 49 and 4! are secured to the opposite sides of the rocker 15 by means of the bolt 31 which secures the spring 35 to the rocker. This bolt also serves to electrically connect the two fingers 3B and All together. The fixed contact members Ma and Ma are-similar to the previously described fixed contact members Ma and lea and are adjustably mountedin adjustable brackets 2t secured to terminal posts Q3 and 54 mounted in the top plate I in the same manner that the fixed contact members i511 and Na are adjustably mounted in adjustable brackets "26 secured to the terminal posts W. A stop 55 is associated with the finger E6 to position it when it is out of engagement with the associated fixed contact member Qua, but no stop is provided for the finger M since the spring 35 performs this function. In order to permit the low resistance contact buttons on the finger 4| to engage the fixed contact member Ma, a hole 36 (see Fig. 4) is formed in the spring 35, which hole receives the contact button with considerable clearance. The fixed contact members are so adjusted that when the rocker occupies its normal position'to which it is biased by the pendulum-armature 34, both contacts "t's 4sa and il .la will be closed, but that when the armature moves a small distance in a clockwise direction, as viewed in Figs. 3 and 5, the contact 4IM'a will open, and that when the armature moves a small distance in the oppositedirection rangement, it will be seen that the low resistance contact buttons of the fixed contact members can be adjusted relative to the contact buttons which are provided on the flexible contact fingers in all directions, thereby readily enabling any desired contact adjustment to be made.

The relay also comprises a suitable motor device for moving the rocker l5 between its'two extreme positions to alternately operate the contacts 18-4811 and lt-Ifia. Thismotor device may assume any one of three different forms depending upon the use to which the relay is to be put. When the relay is to be used as a code transmitter this motor' device consists of an electromagnet C'having pole pieces 3 3a and 3537] secured by'means of studs 3! to the plate portions 2a and'Zb of the frame 2 in parallel spaced relation and conne'ctedtogether at one en'd'by a core 33 surrounded by a winding 33. The free ends of the pole pieces cooperate with 'an armature '34 which is attached to the lower end of a metallic fiat spring 35, the upper end of which is secured to the center of the 'rocker'lfi withina vertical groove 36 by means of 'a bolt 31, as best seen in Figs. 4 and 5. The armature 34' together with the'sp'rin'g 35 serve as a pendulum to 'bias the rocker l5 to its central position in which'it is shown in thedrawings and in which-the conthe contact 4t-t0a will open.

Referring now to the wiring diagram illustrated in Fig. 6, it will be seen that the one terminal of the winding 33 is connected by a wire 33a with the't'erminal post 53, and the other terminal is conn cted by a wire 33b with the terminal post 2 2. A source of electromotive force here shown as a battery B is connected with'the terminal posts 32 and M'through a switch S. It follows, therefore, that when the switch S is closed winding 33 will be supplied with current provided contacts diliiia an'd'dil'ia are then both closed, but'that the supplyof current to thewindin'g '33 will. be'interrupted when either contact dil iiia or contact lh ti a becomes opened. In order to prevent excessive arcing of the contacts and' i li ia, a rectifier Ris connected in multiple withthe winding This 'rectifier'is-supp'orted 'at'its endsin slotstll provided in'the-pla'te portions 20. and 2b of the frame 2 as shown in Figs. '2 and 3.

As shown in the drawing, the switchs is open so that the'winding 33 is deenergized, Rocker I 5 therefore occupies its normal positi n to which it is biased by the pendulum-armature 3 and under these conditionsthe contacts iii-48a and l'.-li'&a are all open, but the control contacts it-tile and' H- iia are .both closed. IC-will. now assume that switch 6 becomes closed. Since-contacts 40--4Ga and 4I4Ia are both closed, current from battery B is supplied to winding 33, and flux lines are therefore set up in the air gap between the pole pieces 30a and 3012. These flux lines thread the armature 34, and as will be readily understood, exert a force on the armature which rotates it and hence the rocker I5 in a clockwise direction as viewed in Fig. 3. The contact 4I-4Ia is so adjusted that when the armature has swung to the position in which it is between the lower ends of the pole pieces 36a and 30b, this contact will open and will deenergize winding 33. The armature 34, however, will continue to swing in the direction it was previously moving until the kinetic energy which the rotating parts have acquired is expended in stressing the contact fingers I8 and in bending the spring 35 which supports the armature. When this happens, the energy stored in the contact fingers and the spring 35, and in armature 34 due to its elevated position will reverse the direction of rotation of the rocker I5, so that it will now rotate in a counterclockwise direction. During this latter rotation contact 4I4Ia will again become closed. Due, however, to the inductance of winding 33, the field between the pole pieces 33a and 3% will build up slowly, and since the rocker is now rotating in a counterclockwise direction, as viewed in Fig. 3, by the time the field has built up between the pole pieces to its normal value the pendulum armature 34 will have swung to the position where the electromagnet will have little effect on the armature. As soon as the armature moves a small distance to the right of its normal position as viewed in Fig. 3, contact 4I3-- i3a will open and will deenergize winding 33. It will be seen therefore that winding 33 will be deenergized as soon as the armature moves a small distance to either side of its neutral or gravity biased position. When the rocker reaches its extreme counter-clockwise position as viewed in Fig. 3, the energy stored in the contact fingers I9a.,' the spring 35 and the pendulum 34 will cause the rocker I5 to again rotate in a clockwise direction. As soon as the rocker reaches the position in which contact All-43a closes, electromagnet C will again become energized and will again cause a force to be exerted on the pendulum-armature 34 tending to accelerate it. The parts are so proportioned that the energy supplied to the rocker I5 during this clockwise rotation is greater than that expended in overcoming friction and other losses during the clockwise rotation of the rocker and the previous counter-clockwise rotation together with that expended in overcoming the opposing force of the magnetic pull on the armature during the previous counterclockwise rotation, so that the rocker starts to oscillate at a period which depends upon the thickness, stiiiness and length of the spring in combination with the mass of the pendulum-armature. These parts can be varied to provide any desired code speed within the limits of the apparatus.

It will be apparent that when the rocker I5 is oscillated the contacts I6I3a and I3--I9a will be alternately opened and closed at the frequency of oscillation of the rocker. These contacts may be used for coding purposes or to control any desired circuits.

It should be pointed out that the double break arrangement provided for the energizing circuit for the winding 33 by the contacts 4Il4fla and 4I--4Ia reduces energy requirements to a minimum and tends to keep the energy in the energizing winding 33 fairly constant for wide variations of applied voltage, and in consequence thereof tends to keep a constant code speed for voltage ranges such as may be expected in battery circuits.

It should also be pointed out that the motion of the rocker I5 permitted by the flexure of the contact fingers after the contacts become closed causes the pressure on the contacts to continue to increase until the pendulum-armature reaches the end of its stroke. This assures ample contact pressure with a minimum amount of energy in the operating winding.

It should be pointed. out that the use of a spring in place of a rigid member for attaching the pendulum-armature 34 to the rocker I5 eliminates shocks to the parts when the contacts 011 one side or the other of the rocker become closed and also permits of wider amplitudes for the pendulum-armature. These wider amplitudes in turn, permit lower stresses in the contact fingers, which increases the life of the fingers and also permits more uniform code speed stability to be obtained with changing voltage conditions such as are liable to be encountered in operation.

As will be apparent from an inspection of the drawing, the pendulum-armature 34 possesses considerable mass, and unless some means are provided to prevent it from swinging during handling of the relay, damage is likely to result to the strips I6 and II which support the rocker I5, to the contacts, or to other parts of the relay. In accordance with my present invention, I prevent the armature from swinging by means of two screws 46 and 41, the upper ends of which are screwed into tapped holes in the armature 34 to positions in which shoulders formed on the screws engage the bottom of the armature. The lower ends of the screws 46 and 41 extend downwardly through clearance holes 48 in the bottom plate 3 and into holes 49 formed between split portions of a bracket 50. The bracket 50 is secured to the underside of the bottom plate 3,

and the lower ends of the screws are clamped between the split portions of the bracket by means of clamping screws 5I which draw the split portions together and cause them to securely grip the lower ends of the screws 46 and 41. When the screws are thus gripped, they are prevented from moving in all directions, and it wil be seen, therefore, that the pendulum-armature 34 and rocker I5 will then be securely held in their normal positions in which they are shown in the drawing.

In applying the screws 46 and 41 the clamping screws 5| are first loosened, and the screws 46 and 4'! are then inserted upwardly through the split portions of the bracket 50 and the holes in the base plate 3 and are screwed into the holes in the pendulum-armature by means of a screw driver which is inserted into a saw kerf provided in the lower ends of the screws. The clamping screws 5I are then tightened. When it becomes desirable to place the relay in service, the clamping screws 5| are first loosened and the screws 46 and 41 are then removed, after which suitable plugs are inserted in the holes in the clamping plate 50 and clamped in place by means of the clamping screws 5| to prevent the entry of foreign sub-stances through the holes in the clamping viewed in Fig. 8.

screwed onto the outer ends of the screws.

tive method for protecting the relay parts during shipment.

Referring now to Figs. 8 and 9, I have here shown the relay constructed in the manner necessary to permit it to be used as a neutral direct current relay. As here illustrated, the driving contacts 4ildila and 4 l-d la have been removed and the pendulum-armature 34 and its associated flexible supporting spring 35 have been replaced by an armature 55 which is secured to the rocker l5 by means of a rigid strip 56. The strip 56 is considerably shorter than the strip 35, and is secured to the rocker at its upper end by means of a bolt 51 having a conical head 58. Further, as here illustrated, the electromagnet C has been replaced by an electromagnet D comprising a pair of pole pieces 553a and 5% secured to' the opposite ends of a magnetizable core 6!! which is surrounded by a winding El. The pole pieces 59a and 5% are also secured to the plate portions 2a and 2b of the frame 2 in vertical positions, and are provided at their upper ends with magnetizable block 590 and 59d toward which the armature is adapted to move when the electromagnet becomes energized. The length of the armature is such that it is free to swing between the pole pieces toward the blocks 59c and 59d, and in order to prevent the armature from actually touching the blocks, non-magnetizable stop pins We are provided in the blocks in positions to engage the left-hand face of the armature, as The rocker I5 is constantly biased to the position in which the contacts 99-4911 are closed and the contacts l8-|8a are open by means of a coil spring 62 one end of which surrounds the head 58 of the bolt 5? and the other end of which engages a spring support 63. The spring support 63 is secured to the top plate I by means of a bolt 64 which is mounted in the top plate in the same location as the terminal post 43 in Fig. 1. For the purpose of limiting the movement of the armature in response to the bias of the spring 62, a pair of adjustable stop screws 65 are provided. These screws are adjustably screwed through threaded holes formed in a transverse member 56 secured at its ends to the plate portions 2a and 2b of the frame 2, and are arranged to be locked in adjusted positions by means of lock nuts 6'! The leads 6B and 69 of the winding 6! are connected with the terminal posts t2 and 44 to facilitate making electrical connection with the winding and a resistor H3 is shown shunted across the winding to provide the desired operating characteristics. This resistor is supported between the plate portions Zaand 2b in the same manner as the rectifier R, is supported in Fig. 1. The remaining parts of the relay shown in Figs. '8 and 9 are identical with those shown in Fig. 1.

With the relay constructed in this manner it will be apparentthat when the winding 6| is deenergized, the rocker will be held by the spring 62 in the position in which the contacts l9l9a are closed and the contacts l8l8a are open. When, however, the winding Bi is supplied with current of either polarity, the flux set up between the pole pieces will attract the armature and will thus move the rocker to the position in'which the contacts I 2E'8a, are closed and the contacts l9l9a are open. It should be pointed out that due to the presence of the magnetizable blocks 59c and 53d and the arrangement of the armature and pole pieces shown, a very fast response of the armature to the energization of the winding is provided. This is particularly desirable when the relay is to pick up on the pulses of coded current. It should also be pointed out that when the relay is operated as a neutral relay, the contacts lie-i911 correspond to the usual back contacts, while the contacts lB-lila correspond to the usual front contacts.

When it is desired to use the relay for a code following relay, the rocker I5 is biased to one of its extreme positions by means ofthe spring 62 in the same manner as shown in Figs. 8 and 9, and is provided with a bifurcated driving arm 10 in the manner shown in Fig. 10. This arm is secured to the rocker by means of the screw 51, and the bifurcations thereof are provided with confronting rounded buttons 7! between which the upper end of the hinged armature E2 of a motor element is adapted to extend. For example, the armature l2 may be the armature 20 of the motor element described in my prior Patent No. 2,057,605, granted October 13, 1937, for Electrical relays. As will be apparent from an inspection of this patent, the armature 2E! will respond to current of one polarity only, and is adapted when the motor element is energized by current of the proper polarity to move toward the left far enough to open the contacts l9i9a and close the contacts l8l 8a.

Although I have herein shown and described only a few forms of electrical relays embodying my invention, it is to be understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. An adjustable contact structure for cooperation with a movable flexible contact finger comprising a terminal post having a cylindrical end, a bracket having one leg mounted on said end in such manner that said bracket can be slid axially along and rotated to different angular positions relative to said terminal post, means for clamping said bracket in an adjusted position relative to said terminal post, and a screw threaded through another leg of said bracket at right angles to said post and provided at one end with a low resistance contact button which is adjustable radially with respect to said post by means of said screw.

2. An adjustable contact structure comprising a supporting post, a contact member, and means adjustable axially along, circumferentially about, and radially with respect to, said post for securing said contact member to said post to permit adjustment of said contact member in all directions with respect to said post.

3. An adjustable contact structure comprising an insulating support, a terminal post mounted on said support and provided with a portion which projects from'one side of said support, a bracket carried by said portion and movable axially along and circumferentlally about said portion, and a contact member secured to said bracket by means permitting radial movement of said contact member relative to said terminal post, whereby said contact member is adjustable in all directions relative to said terminal post.

HERMAN G. BLOSSER.

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