US3249717A

US3249717A - Double-throw relay with positive closure and operation of contacts

Info

Publication number: US3249717A
Application number: US155970A
Authority: US
Inventors: Paul N Martin
Original assignee: Consolidated Electronics Industries Corp
Current assignee: Consolidated Electronics Industries Corp
Priority date: 1961-11-30
Filing date: 1961-11-30
Publication date: 1966-05-03
Anticipated expiration: 1983-05-03

Description

May 3, 1966 P N. MARTIN 3,249,717

DOUBLE-THROW RELAY WITH POSITIVE CLOSURE AND OPERATION OF CONTACTS Filed Nov. '30, 1961 A rropmrys United States Patent 3 249,717 DOUBLE-THROW RE LAY WITH POSITIVE CLO- SURE AND OPERATION OF CONTACTS Paul N. Martin, Frederick, Md., assignor to Consolidated Electronics Industries Corp., New York, N.Y., a corporation of Delaware Filed Nov. 30, 1961, Ser. No. 155,970 Claims. (Cl. 200-104) This invention relates to an electromagnetically operated relay and more particularly to the arrangement of electrical contacts and their supporting structure.

One of the objects of the present invention is to provide an improved, compact, electromagnetically operated relay having a rugged contact assembly with contact terminals symmetrically arranged and with the contacts easily available for trimming adjustment.

Other objects are to provide an improved and easily adjustable biasing spring arrangement to bias the anmature. of the relay to one of two alternate terminal positions, and to provide an improved armature retracting arrangement.

Further objects will be apparent from the following description of the invention, together with the drawings, in which:

FIG. 1 shows a side view of a relay constructed in accordance with the invention with certain parts broken away to show the inner construction thereof; and

FIG. 2 is a top view of the relay shown in FIG. 1.

Basically, the relay of the present invention comprises an electromagnetic structure including one-or more operating coils and an armature movable from one position to another by means of a magnetic field produced by the coils. Both the armature and the coils are supported by, but spaced from, a base structure. Also aifixed to and extending through the base structure is a plurality of terminal pins which are insulated from each other and, usually, from the base structure as well. One of the terminal pins supports a relatively fix'ed contact and a second pin supports a resilient spring structure by means of which a movable contact is held in position adjacent to the fixed contact. A third terminal pin carries a support bar which supports another relatively fixed contact so positioned that the movable contact may make connection alternatively with either the latter fixed contact or the first-mentioned fixed contact. The armature engages the movable contact to move it from one of the fixed contacts to the other. The spring structure may be provided with separate contacts on each of two resiliently movable arms extending in the same direction and linked together near their outer ends to achieve more positive operation. Locking means, which may form a part of or be attached to the base structure, are provided to assist the third terminal pin to hold the support bar rigidly in place. A compression spring, operating between the relay frame and the armature and held by a threaded member on the latter returns the armature to its deenergized position.

The electromagnetic structure of the relay in FIG. 1 is supported on a non-magnetic frame 11 which in turn is firmly attached to a base structure 12 in such a way as to be spaced a short distance above the base. The electromagnetic section comprises two

coils

13 and 14, of which only the coil 13 appears in FIG. 1, located on a pair of ferromagnetically

soft cores

16 and 17, respectively, which, in turn, are joined both mechanically and magnetically to the frame 11 as well as to a soft iron plate 18 that constitutes a magnetic bridge between the cores.

The electromagnetic structure just described is not novel, itself, and other electromagnetic arrangements may be used instead. For example, a single-coil, single-core ice electromagnetic structure could be used with the present relay with, perhaps, some loss in efficiency, depending upon the precise design of the elements, but without any basic change in the location and operation of the contacts.

The frame 11 has downwardly extending sides 1921, of which only the

sides

19 and 21 appear in FIG. 1, that engage slots in the base 12. Corresponding sections of the

sides

19 and 20 are removed to form a pair of tongues, of which only the tongue 23 is shown that support the ends of an axle 25. The axle 25 in turn supports a ferromagnetically soft armature 26 which is free to rotate or pivot, on the axle 25 in response to magnetomotive force produced when the

coils

13 and 14 are energized. In order to permit the upper surface of the armature 26 to move fiat against the lower surface of the

cores

16 and 17 in response to the aforementioned magnetomotive force of attraction, the precise position of the axle 25 may be altered slightly after the relay is constructed by bending the tongues 23 and 24 slightly to move them up or down, whichever'is necessary.

At the rear of the frame 11 is a platform 28 which supports a spring biasing structure that holds the armature 26 normally away from contact with the

cores

16 and 17. This spring biasing arrangement comprises a threaded bolt 29 attached to the anmature 26 and extend ing up through an opening in the platform 28. A nut 31 is attached to the upper end of the bolt 29, and a spring 32 is compressed between the nut 31 and the platform 28. A pair of

eyelets

33 and 34 maybe slipped onto the bolt 29 to hold the ends of the spring in position. If the friction of the spring 32 on the platform 28 is desirable as means of absorbing the shock of move ment of the armature 26, the eyelet 34 may be omitted.

As the armature 26 pivots counterclockwise about the axle 25 in response to the magnetomotive force produced when the

coils

13 and 14 are energized, the spring 32 is compressed between the platform 28 and the nut 31.v As soon as the magnetomotive force is removed, the spring 32 retracts the armature 26 by rotating it clockwise to its alternative position. The nut 31 is accessible to adjust with great accuracy and stability the pressure provided by the spring 32, and therefore the exact magnetomotive force required to retract the armature 26 from its clockwise, or de-energized, position to its counterclockwise, or energized, position may easily be adjusted to a predetermined value.

Normally, the base structure 12 is made of some sturdy material such as steel and is provided with a plurality of terminal pins which are supported in glass insulating members. Two of these terminal pins, which are identified by reference characters 36 and 37, are connected to the

coils

13 and 14 to supply energizing current to them.

The connecting wire attached to pin 36 is indicated by reference character 38 but that connected to pin 37 is not shown in this figure. I

A terminal pin 39 to the left of the terminal pin 37 supports a bracket 41 which in turn carries a relatively fixed contact 42. The reason for saying that the contact 42 is relatively fixed is that the bracket 41 and the terminal pin 39 have some, although relatively little, resilience. To casual inspection, the contact 42 appears to be immovable. While only a single terminal pin 39 is indicated in this figure, any number of similar pins may be include-d in the relay and in many embodiments, a whole row of pins may be lined up, one behind the other.

On the right-hand side of the base structure 12 is another terminal pin 43, which extends through the base structure and is attached to a support bar 44 inside the relay housing. The support bar is a relatively rigid member and may be, for example, a sturdy metal tube Patented May 3, 1966 that extends over the area in which the terminal pin 39 is located. A convenient way of attaching the bar 44 to the pin 43 is to drill a hole through the bar large enough to slip the bar onto the end of the pin 43. Then the pin and bar may be welded, or otherwise joined, together. Near the outer end of the support bar 44 is another bracket 46 which carries a relatively fixed contact 47; although, as in the case of the contact 42, the actual movement of the contact 47 may be very slight.

In order to keep this support bar 44 from vibrating excessively or moving under pressure of the contacts, means are provided in addition to the pin 43. In the present embodiment the means include an insulating block 48, which is firmly attached to the base structure 12 by a number of machine screws 49 and a spring 51. The block 48 is provided with a slot 52, or with several such slots, in the event that there is more than one bar 44. Each slot has a V-shaped bottom in which the bar 44 rests under pressure from the spring member 51, which is preferably either of an insulating type or is insulated from the support bars 44 by a piece of material 53, such as mica.

Between the terminal pins 39 and 43 is another terminal pin 54. In the usual case of a multi-pole relay there will be a row of similar pins, and a portion of another pin 54a is visible in FIG. 1. The spring means comprises a pair of resilient blades 56 and 57 joined together at one end, which is attached to each of the contact terminal pins 54. These spring blades extend out -into the region between the relatively

fixed contacts

42 and 47, and they support, at these outer ends, contact means in the form of

contact buttons

58 and 59, respectively.

The contact 59 is normally closed against the contact 47, while the contact 58 is normally open away from the contact 42, when the armature 26 is in its retracted position. When the armature 26 is moved to its alternative position against the lower ends of the

cores

16 and 17 by the magnetomotive force produced therein, the contact 58 must be closed against the contact 42 and the contact 59 must be open, i.e., away from the contact 47. In order to accomplish this, a pair of

arms

61 and 62 extends downward from the sides of the armature 26. An insulated bar 63 extends between the

arms

61 and 62 and between the blades 56 and 57. As in the case of the tongues 23 and 24 the

arms

61 and 62 may be bent slightly to modify the location of the bar 63. In addition, the

contacts

42 and 47, as well as the

contacts

58 and 59 are located to one side of the rest of the relay structure and are easily accessible for adjustment prior to the time that the relay is inserted into the can 64.

While the contact 47 is shown as being approximatelydirectly above the contact 42, it is preferably slightly 011 to one side, and the

contacts

42 and 47 are at an angle to the direction of motion of contacts 58 and'59. The reason for this is that it permits a slight sliding, or rubbing, action of the surfaces of the contacts 58 against the contacts 42 and of the contacts 59 against the contacts 47. This removes any corrosion products andassured good, low-resistance contact between the contact 42 with the contact 58, on the one hand, and the contact 47 with the contact 59 on the other.

This scrubbing action is further assisted by having the

contacts

58 and 59 located on separate blades 56 and 57. The blade 56 can then be given an upward bias and the blade 57 a downward bias so that, no matter how far upward, within reason, the rod 63 pushes the upper contacts 59 against the relatively fixed contacts 47, the lower contacts 58 will follow along, and, conversely, no matter how far downward the rod 63 pushes the lower contacts 58 against the lower relatively fixed contacts 42, the upper contacts 59 will follow along. This increases the distance between the adjacent contact faces of the open pair of contacts for either position of the armature 26.

An additional safety feature that may be incorporated into the spring blade arrangement to assure proper operation is a pin 65 which links the blades 56 and 57 together. In order to keep the pin 65 from acting as a stiffener for the blades, it should preferably be loosely interlocked with them. The pin 65 may be inserted in holes in the blades 56 and 57 and the ends of the pin peened over so as to prevent its slipping out. The advantage of including pin 65 is that it provides positive release of the contact 58 from the lower contact 42 when the

coils

13 and 14 are de-energized, and it provides positive release of the contact 59 from the contact 47 when the coils are energized. This avoids the possibility of having one pair or the other of contacts weld itself shut if too high a current is drawn through it momentarily. Such an improvement is desirable especially in the case of the relay operating at some completely inaccessible location, such as a space vehicle, and even in the case of an accessible location, the fact that most relays of the type under discussion are sealed within a can 64, makes it very difiicult to correct any malfunctioning parts after the relay has been completely assembled.

FIG. 2 shows a top view of the relay in FIG. 1. The rod 63 and the

arms

61 and 62 supported from the armature 26 are more clearly apparent in FIG. 2 than in FIG. 1. In addition, the arrangement of the plurality of upper, relatively fixed contacts 47a-47d, together with their associated brackets 46a-46d, are shown, as are the ends of the lower brackets 41a-41d.

FIG. 2 also shows more clearly the arrangement of the

coils

13 and 14 of the electromagnetic portion of the relay together with the soft iron member 18. The

cores

16 and 17 are indicated in dotted outline since they are under the plate 18 and are attached thereto by machine screws 66 and 67, respectively. The

ooils

13 and 14 are either wound in opposite directions or are so connected as to produce aiding magnetic flux in the member 18. That is, if the current flowing in the coil 13 makes the upper end of the core 16 (the end attached to the member 18) a north pole, the current in the coil 14 must then be in such direction as to cause the upper end of the core 17 to be a south pole. Thus, magnetically speaking, the

cores

16 and 17 are connected in series. This simplifies the magnetic circuit, which is completed by having the flux be directed downward in the core 17 and into the armature 26 (see FIG. 1) and through the armature 26 back to the core 16. v

While the invention has been described in terms of a specific embodiment, it will be understood by those skilled in the art that modifications may be made therein, in addition to those which have been specifically pointed out hereinabove, which will still be within the scope of the invention as defined in the following claims.

What is claimed is:

1. A relay comprising: a movable magnetic armature; electromagnetic means to move said armature from one position to an alternate position; at least two fixed contacts; a base structure; a terminal pin extending through said base structure, one of said contacts being attached to and supported by said terminal pin; a second terminal pin extending through said base structure; support means attached to said second terminal pin, the other of said fixed contacts being connected to and supported by said support means in close juxtaposition with said one of said fixed contacts and near one edge of said base structure to facilitate adjustment of the positions of said fixed contacts; locking means attached to said support means to cooperate with said second terminal pin in preventing movement of said support means; a third terminal pin extending through said base structure between said first and said second terminal pins; resilient spring means attached to said third terminal pin, said spring means having contact means at one end thereof between said two fixed contacts; and means attached to said armature and tosaid spring means to move said end of said spring means to force said contact means into connection with said fixed contacts when said armature is in said one position and to force said contact means into connection with the other of said fixed contacts when said armature moves to said alternate position.

2. A relay comprising: a movable armature; means' to move said armature from one position to an alternate position; at least two relatively fixed contacts; a base structure; a terminal pin extending through said base structure; means attaching a first one of said contacts to said terminal pin; a second terminal pin extending through said base structure; a conductive support bar attached to said second terminal pin and having one end extending in the direction of said first terminal pin; means attaching a second one of said fixed contacts to said end of said support bar in close juxtaposition with said one of said fixed contacts and near one edge of said base structure to facilitate adjustment of the positions of said fixed contacts; locking means attached to said support bar to cooperate with said sec-v ond terminal pin in'preventing movement of said support bar; a third terminal pin extending through said base structure in the region between said first and said second terminal pins; bifurcated spring means joined together at one end thereof, said end of said spring means being attached to said third terminal pin, the bifurcated ends of said spring means being resiliently movable; a first contact button attached to one of said bifurcated ends in juxtaposition with said relatively fixed contacts; a second movable contact attached tothe other of said bifurcated ends and facing in the opposite direction from said first movable contact and in juxtaposition with said second fixed contact; rigid means attached to said armature and engaging each of said'bifurcated ends to move said bifurcated ends to force said first movable contact into connection with said first fixed contact when said armature is moved from one p osition to the alternate position and to force said second movable contact into connection with said second fixed contact when said armature is moved from one position to the alternate position; and inelastic coupling means connecting said bifurcated ends together to remove said second movable contact f-orceably from said second fixed contact when said armature is moved to said alternate position; and to remove said first movable contact forceably from connection with said first fixed contact when said armature is moved to said one position.

3. A relay comprising: an axle; an armature pivotally supported thereon; means to pivot said armature from one position to an alternate position; a base structure; a first terminal pin extending through said base structure; a first relatively fixed contact attached to said terminal pin; a second terminal pin extending through said base structure; a conductive, relatively rigid support bar attached to said second terminal pin and having one end extending into the proximity of said first contact; a second relatively fixed contact attached to said one end of said support bar in close juxtaposi tion with said one of said fixed contacts and near one edge of said base structure to facilitate adjustment of the positions of said fixed contacts; locking means attached to said support bar and to said base structure to cooperate with said second terminal pin in prevent-. ing movement of said support bar; a third terminal pin extending through said base structure betweensaid first and said second terminal pins; a pair of resilient springblades joined together and attached to said third terminal pin, one end of each of said blades extending into the space between said first and second relatively fixed contacts, said end of said blades being resiliently movable; a first movable contact attached to said end of one of said blades; a second movable contact attached to said end of the other of said blades, aid movable contacts facing in opposite directions and being directly between said relatively fixed contacts; rigid means connected to said armature and to said blades to move said blades in order to force said first movable contact into connection with said first relatively fixed contact when said armature is in said one position and, alternately, to force said second movable contact into connection with said second relatively fixed contact when said armature is in said alternate position; and inelastic coupling means connecting said blades together, whereby movement of said armature into said one position forceably disengages said second movable contact from said second relatively fixed contact and movement of said armature into said alternate position forceably disengages said first movable contact from said first relatively fixed contact.

4. The relay of claim 3 in which said relatively fixed contacts are disposed at an angle to each other and to said movable contacts to provide a scrubbing action of said movable contacts upon said relatively fixed contacts.

5. The relay of claim 3 in which said rigid means comprises a rod dependently attached to said armature and extending substantially parallel to said axle and between said blades, and said blades being oppositely spring-biased against said rod.

6. A relay comprising: an axle; an armature pivotally mounted thereon; electromagnetic means to pivot said armature from one position to an alternate position; a base structure; a first terminal pin extending through said base structure; a first relatively fixed contact attached to said terminal pin; a second terminal pin extending through said base structure; a conductive, relatively rigid support bar attached to said second terminal pin and having one end extending into the proximity of said first contact; a second, relatively fixed contact attached to said one end of said support bar in close juxtaposition with said one of said fixed contacts and near one edge of said base structure to facilitate adjustment of the positions of said fixed contacts; locking means attached to said support bar and to said base structure to cooperate with said second terminal pin in preventing movement of said support bar; a third terminal pin extending through said base structure between said first and said second terminal pins; a pair of resilient spring. blades joined together and attached to said third terminal pin, one end of each of said blades extending into the space between said first and second relatively fixed contacts, said end of said blades being resiliently movable; a first movable contact attached to said end of one of said blades; a second movable contact attached to said end of the other of said blades, said movable contacts facing in opposite directions and being directly between said relatively fixed contacts; means connecting said armature to said blades to move said blades to alternate extremities of a path in order to force said first movable contact into connection with said first relatively fixed contact when said armature is in said one position and alternately to force said second movable contact into connection with said second relatively fixed contact when said armature is in said alternate position, said lastnamed means comprising a pair of arms extending from opposite sides of said armature, and a rod held by saidarms and extending therebetween in a direction substantially parallel to said axle, said arms being deform able to align said rod, said rod passing between said blades, and said blades being oppositely spring-biased 7 against said rod; and inelastic coupling means connecting said one end of said blades together, whereby said second movable contact is forceably separated from said second relatively fixed contact when said armature is in said one position and said first movable contact is forceably separated from said first relatively fixed contact when said armature is in said alternate position,

7. A relay comprising: a base structure; a frame spaced from said base structure; a plurality of sides extending from said frame and engaging said base structure to attach the frame thereto; an axle supported on said frame; a magnetizable armature pivotally mounted on said axle; electromagnetic means mounted on said frame to pivot said armature from one position to an alternate position; a first terminal pin extending through said base structure; a first relatively fixed contact attached to said terminal pin; a second terminal pin extending through said base structure; a conductive, relatively rigid support bar attached to said second terminal pin and having one end extending into the proximity of said first contact; a second relatively fixed contact attached to said one end of said support bar in close juxtaposition with said one of said fixed contacts and near one edge of said base structure to facilitate adjustment of the positions of said fixed contacts; locking means attached to the other end of said support bar and to said base structure to cooperate with said second terminal pin in preventing movement of said support bar; a third terminal pin extending through said base structure between said first and said second terminal pins; a pair of resilient spring blades joined together and attached to said third terminal pin, one end of each of said blades extending into the space between said first and second relatively fixed contacts, said end of said blades being resiliently movable; inelastic means connecting said movable end of said blades together; a first'movable contact attached to said one end of one of said blades; a second movable contact attached to said end of the other of said blades, said movable contacts facing in opposite directions and being directly between said relatively fixed contacts; rigid means connected to said armature and to said blades to move said blades in order to force said first movable contact into connection with said first relatively fixed contact when said armature is in said one position and, alternately, to force said second movable contact into connection with said second relatively fixed contact when said armature is in said alternate position, said armature forceably separating said second movable contact from said second relatively fixed contact when said armature is in said one position and forceably separating said first movable contact from said first relatively fixed contact when said armature is in said alternate position. I

8. Therelay of claim 7 in which said locking means comprises a rigid member attached to said base structure and having a groove to receive said other end of said support bar, and a spring plate attached to said rigid member to hold said other end of said support bar in said groove.

9. The relay of claim 8 comprising, in addition, a pair of tongues extending from said sides to support said axle, said tongues being slightly deformable to align said axle with said electromagnetic means, said support bar comprises a hollow tubular member having an opening therethrough at an angle to the axis thereof, one end of said third terminal pin fitting through said opening and being affixed therein.

10. A relay comprising: a base structure; a frame spaced from said base structure; a plurality of sides extending from said frame and engaging said base structure to attach the frame thereto; an axle supported on said frame; a magnetizable armature pivotally mounted on said axle; electromagnetic means mounted on said frame to pivot said armature from one position to an alternate position; a threaded member extending from said armature; a compression spring surrounding said member, one end of said spring engaging said frame; means threaded on said threaded member to move along the latter, said last-named means engaging the other end of said spring to compress the spring when said armature is pivoted to said alternate position, thereby urging said armature back toward said one position; a first terminal pin extending through said base struc ture; a first relatively fixed contact attached to said terminal pin; a second terminal pin extending through said base structure; a conductive, relatively rigid support bar attached to said second terminal pin and having one end extending into the proximity of said first contact; a second relatively fixed contact attached to said one end of said support bar in close juxtaposition with said one of said fixed contacts and near one edge of said base structure to facilitate adjustment of the positions of said fixed contacts; locking means attached to the other end of said support bar and to said base structure to cooperate with said second terminal pin in preventing movement of said support bar; a third terminal pin extending through said base structure between said first and said second terminal pins; a pair of resilient spring blades joined together and attached to said third terminal pin, one end of each of said blades extending into the space between said first and second relatively fixed contacts, said end of said blades being resiliently movable; a link coupling said end of blades together; a first movable contact attached to said one end of said blades; a second movable contact attached to said end of the other of said blades, said movable contacts facing in opposite directions and being directly between said relatively fixed contacts; and means connecting said armature to said blades to move said blades in order to force said first movable contact into connection with said first relatively fixed contact and, simultaneously to force said second movable contact to separate from said second relatively fixed contact when said armature is in said one position, and to force said second movable contact into connection with said second relatively fixed contact and, simultaneously, to force said first movable contact to separate from said first relatively fixed contact when said armature is in said alternate position, said last-named means comprising a bar extending between said blades at said one end thereof adjacent to said link.

References Cited by the Examiner UNITED STATES PATENTS 1,919,991 7/1933 Starie 20087 2,946,872 7/1960 Siebers 20087 2,951,134 8/1960 Lazich 200-87 2,955,174 10/1960 Richert 20087 2,960,583 11/ 1960 Fisher et al. 20087 3,033,957 5/1962 Dean 20087 3,036,176 5/1962 Kenyon et al. 20087 BERNARD A. GILHEANY, Primary Examiner.

MAX L. LEVY, Examiner. B. DOBECK, R. N. ENVALL, Assistant Examiners.

Claims

1. A RELAY COMPRISING: A MOVABLE MAGNETIC ARMAURE; ELECTROMAGNETIC MEANS TO MOVE SAID ARMATURE FROM ONE POSITION TO AN ALTERNATE POSITION; AT LEAST TWO FIXED CONTACTS; A BASE STRUCTURE; A TERMINAL PIN EXTENDING THROUGH SAID BASE STRUCTURE, ONE OF SAID CONTACTS BEING ATTACHED TO AND SUPPORTED BY SAID TERMINAL PIN; A SECOND TERMINAL PIN EXTENDING THROUGH SAID BASE STRUCTURE; SUPPORT MEANS ATTACHED TO SAID SECOND TERMINAL PIN, THE OTHER OF SAID FIXED CONTACTS BEING CONNECTED TO AND SUPPORTED BY SAID SUPPORT MEANS IN CLOSE JUXTAPOSITION WITH SAID ONE OF SAID FIXED CONTACTS AND NEAR ONE EDGE OF SAID BASE STRUCTURE TO FACILITATE ADJUSTMENT OF THE POSITIONS OF SAID FIXED CONTACTS; LOCKING MEANS ATTACHED TO SAID SUPPORT MEANS TO COOPERATE WITH SAID SECOND TERMINAL PIN IN PREVENTING MOVEMENT OF SAID SUPPORT MEANS; A THIRD TERMINAL PIN EXTENDING THROUGH SAID BASE STRUCTURE BETWEEN SAID FIRST AND SAID SECOND TERMINAL PINS; RESILIENT SPRING MEANS ATTACHED TO SAID THIRD TERMINAL PIN, SAID SPRING MEANS HAVING CONTACT MEANS AT ONE END THEREOF BETWEEN SAID TWO FIXED CONTACTS; AND MEANS ATTACHED TO SAID ARMATURE AND TO SAID SPRING MEANS TO MOVE SAID END OF SAID SPRING MEANS TO FORCE SAID CONTACT MEANS INTO CONNECTION WITH SAID FIXED CONTACTS WHEN SAID ARMATURE IS IN SAID ONE POSITION AND TO FORCE SAID CONTACT MEANS INTO CONNECTION WITH THE OTHER OF SAID FIXED CONTACTS WHEN SAID ARMATURE MOVES TO SAID ALTERNATE POSITION.