US3487176A - Multiple switch - Google Patents

Description

Dec. 30. 1969 G. M. sTouT 3,487,176

MULTIPLE swITcH Filed Maron 21, 1958 2 sheets-sheet 1 llllllllllhllllllmllll 8/ 82 /0 /N VEN TOR GLEN/v M. srour w? ArTY/S.

Dec. 30, 1969 G. M. sTouT 3,487,176

MULTIPLE SWITCH Filed March 21, 1968 2 Sheets-Sheet 2 FIG.5

3,487,176 MULTIPLE SWITCH Glenn M. Stout, Anoka, Minn., assignor to Seven Cs, Inc., Minneapolis, Minn., a corporation of Illinois Filed Mar. 21, 1968, Ser. No. 714,825 Int. Cl. Htllh 9/26 U.S. Cl. 200- 13 Claims ABSTRACT OF THE DISCLOSURE operation by one of the plungers so that upon depressing the same the spring arms are moved out of engagement with the plungers which have been depressed and the same are returned to raised, non-actuating position. A1- ternately, the latch release bar may be operated by an electromagnet.

This invention relates to electrical switch assemblies and is mor-e particularly concerned with improvements in a multi-station switch of the accumulative latch type.

Multi-station switch assemblies have heretofore been developed for use where it is desired to provide control over a number of operations or to control a sequence of operations. Such switches are useful in home appliances such as electric ranges, washing machines, air-conditioners and like equipment. They are also finding increasing use in more complex electrical equipment such as communication and instrument gear, computer and oflce equipment, and other mechanical equipment employing multiple circuits for control thereof. It is desirable in this type of switch equipment to provide smooth operating devices which are of simple construction, easy to maintain, readily manufactured at low cost, easily installed and removed or replaced, easy to wire and having a high degree `of functional flexibility and versitility. It is, therefore, an object of the present invention to provide an improved switch assembly of the multiple push button type which is of relatively simple construction, which has a minimum of parts, which will operate efciently and smoothly over a long period with minimum attention, which may be readily manufactured at a relatively low cost and which has other desirable characteristics and advantages.

A more specic object of the invention is to provide an improved multi-station switch which includes a plurality of reciprocally mounted switch actuating push rod members and associated guide members providing smooth operation, with the actuating members having a latch arrangement which will positively retain the actuating members in depressed switch operative position until they are released by a positive acting release mechanism.

Another object iof the invention is to provide an improved multiple push button switch having a plurality of push `rod type switch actuating members and spring arms for cooperation with camming and latching sur- United States Patent O ICC faces on the actuating members so as to lock the individu-al push rod members in switch actuating position when they are depressed and a common release bar 0perating on the spring latch arms to automatically release the latched actuating members when actuated.

These and other objects and advantages of the inventlon will be apparent from a consideration of the push button switch structure Which is shown by way of illustration in the accompanying drawings wherein:

FIGURE 1 is a side elevation of a multiple push button assembly of the accumulative latch type which embodies the principles of the invention;

FIGURE 2 is an elevation of the opposite side of the push button switch assembly of FIGURE 1 with portions broken away;

FIGURE 3 is a partial side elevation with portions broken away, of the switch assembly of FIGURE 1, the view being to an enlarged scale;

FIGURE 4 is a cross section taken on the line 4-4 of FIGURE 1, to an enlarged scale;

FIGURE 5 is 4an exploded perspective view showing the elements in the switch assembly of FIGURE 1;

FIGURE 6 is a fragmentary side elevation showing a (modified form of the switch assembly of FIGURE 1; an

FIGURE 7 is a fragmentary exploded perspective view showing portions of the switch assembly of FIGURE 6 to a still larger scale.

The switch assem-bly which is illustrtaed in the drawmgs and which is designed to control a plurality of circuits, includes rnultiple push button rods or plungers, any number of which may be depressed from a normal inoperative position to operative switch actuating position where they are held until released by actuation of a common release bar, the latter being actuated either manually through operation of a push button rod or plunger or automatically by means of a soleonid which may be push button actuated.

Referring to the drawings, there is illustrated a push button switch assembly comprising two frame plates 10 and 10 which are of substantially identical construction except for being rights and lefts. The plates 10 and 10 are of suitable rigid material, such as, sheet steel, and may be stamped or otherwise formed in any desired lengths. The plates 10, 10 include rectangular body portions having bottom edges 12, 12', end edges 13, 13 and top flanges 15, 15'. The plates 10, 10 are assembled to form a supporting frame for the switch elements by positioning them in face-to-face relation with the anges 15, 15 extending in opposite directions. The flanges 15, 15 may be as wide as desired and provided with suitable means for mounting the entire structure in a panel or the like. The body of each of the plates 10 and 10 is provided with a series of closely spaced, generally rectangular apertures 16 and 16 with each aperture 16 aligned in paired relation with an aperture 16 when the plates are assembled so as to form guideways for receiving contact actuators 18 and plunger guides 20 associated with plunger or push rod members 22. In assembled condition the plates 10 and 10 are held in spaced relation at the bottom by a spacer bar 23 and at the top by small spacer sleeves 24 carried on spaced clamping bolts 25 which are disposed along the top margin of the body of the plate 10, the latter constituting in effect the main support plate. The spacing between the plate bodies is slightly greater than the thickness of the plunger members 22 so as to permit free sliding movement of the plunger members 22, in a vertical direction, when the frame is disposed with the flanges and 15 generally horizontal. The frame spacer 23 is apertured to accommodate a series of spaced clamping bolts 26 on which leaf spring contact switch point assemblies 28 are mounted on the outside face of the body portions of the frame plate 10.

Each leaf spring assembly 28 comprises a plurality of sets of stacked contact plates 30 seated in pockets 31 which are formed on an elongate insulating bar 32 by longitudinally spaced partition members 33 with the spaces forming the pockets 31 having a width determined according to the spacing of the bolts 26, each of which is located below a lower corner of an aperture 16 so that when the contact switch assembly 28 is postioned in a pocket 31 the switch plates 30 extend upwardly along the one side of an aperture 16 with the innermost blade 34 of the switch assembly positioned for engagement by the contact actuator 18 which is carried on the plunger 22. The insulating bar 32 and associated partition members 33 may be formed of suitable rigid plastic having electrical insulating characteristics.

The plunger 22 is in the form of a flat plate of rigid material, such as, for example, metal cut from a rectangular strip, so as to provide a relatively wide top portion 35 and a narrower spear-like bottom portion 36. An elongated aperture 37 is provided in the top portion 35 near the bottom margin thereof and extending on the vertical axis for receiving the guide pin 38 which extends from the innermost face of the main support plate 10A and is centered at the top of the aperture 16. The top portion 35 of the plunger 22 is notched out at 39 along the one side edge to provide a relatively long clearance slot when positioned at an aperture 16 adjacent the separating collar 24. The opposite vertical margin of the plunger top portion 35 is notched at 40 to provide a latching slot and at 41 to provide an outwardly and upwardly inclined cam edge 42 for latch spring or latch arm operation as hereinafter described. The top portion 35 of the plunger 22 is provided with an operating button 43 on the top surface of which identifying indicia may be placed.

A plunger guide is associated with each of the plungers 22 and is in the form of a generally rectangular block of a suitable molded plastic having the necessary dimensional stability. The guide 20 is provided with a flat top surface 45 and the end portions are bifurcated or slotted at 46 and 46', the width of the slots being slightly greater than the thickness of the material in the plate 10 and the distance between the slots being slightly less than the width of the aperture 16. The center portion of the guide 20 is thickened as indicated at 50' and when the guide 20 is installed in the frame plate 10 the thickened center portion is seated in a notched out portion 51 in the bottom edge of the aperture 16 which is of complementary shape, with the guide adapted to be positioned So that the longer side is on either side of the frame, as desired. A vertically disposed aperture 52 is provided in the center of the guide 20 which is adapted to receive in free sliding relation the spear-like bottom portion 36 of the plunger 22. The relative dimensions of the aperture 52 and the plunger portion 36 are such that the plunger portion may be canted therein slightly during assembly and disassembly of the plunger with the plate 10 so as to free the slot 37 of the pin 38 and permit the plunger 22 and the associated actuator 18 to be maneuvered into and out of the proper assembled relation with the base plate 10.

The contact actuator 18 is in the form of a block which is preferably molded from a rigid plastic material and which has dimensional stability. It has a vertical dimension which is substantially less than the corresponding dimension of the aperture 16 so that it may have a predetermined path of vertical movement when confined in the aperture 16. The over-all length of the actuator 18 is greater than the width of the aperture 16 in the plate 10 and the end portions are reduced in width and thickness so as to provide extensions 53 and 53 for positioning between the marginal plate portions dening the vertical sides of the apertures 16 and 16 in the plates 10 and 10', with the latter forming tracks for guiding the actuator 18 in its vertical Ipath. A vertically disposed slot 54 of rectangular cross section extends through the actuator 18 and receives in sliding relation the bottom portion 36 of the plunger 22. The slot 54 is aligned with the space between the plates and is centered so as to receive the plunger portion 36. It has a widened portion 54 at the top in which the bottom edge of the plunger top portion 35 is adapted to seat. The bottom face of the actuator 18 is plain and is adapted to abut the top face 45 of the plunger guide 20 when the plunger 22 is depressed to its lowermost position. A return spring 55 has its uppermost end seated in the pocket 56 provided in the bottom face of the actuator 1.8. The spring 55 is carried on the plunger portion 36 and serves to urge the actuator 18 in the direction of its uppermost position. The actuator 18 is widened at the top margin so as to provide outwardly and upwardly inclined surfaces 57 and 57 on the top margins which are adapted to be engaged by the innermost face of the innermost leaf spring 34 in the stack 30 of each spring contact assembly 28 when the actuator 18 is depressd. The top face of each actuator 18 is cut away to provide a relatively shallow recess or lengthwise extending slot 60 Which is of a width sufficient to seat therein the marginal portions of the frame plates 10 and 10 at the top of the slots 16 and 16' when the actuator 18 is in its uppermost position.

Each of the push rods 22 except for one which will be hereinafter referred to, is adapted to be latched in the depressed, switch-actuating position -by operation of a spring arm 63 (FIGURES 2 and 5). The spring latch arm 63 is formed from a length of spring wire, with a bottom end portion at a right angle to the middle portion and curled about a rivet at 64 on the outside face of the frame plate 10 for attachment to the frame. The spring arm 63 extends upwardly to a point near the top of the frame where it is bent at a right angle to the end thereof to provide a short section 65 extending along the face of the plate 10 and again at a right angle to provide end section or terminus 66. The end section 66 extends through an aperture 67 provided in the plate 10 and across the notch 41 in the upper portion 35 of a plunger 22 when the latter is in its uppermost position as shown in FIGURES 1 and 3. The end section 66 of the spring 63 is disposed below the cam surface 42 where it is engaged by the latter, when the plunger 22 is depressed, and moved toward the vertical edge of the section 35 until the latching slot or notch 40 is moved down so as to permit the end section 66 to snap into the same due to the resiliency of the arm thereby operating to hold the plunger 22 in depressed position. The relative position of the latch spring end 66 and the plunger 22 when the plunger 22 is depressed to switch actuating position is illustrated in connection with the plunger 22 in FIGURE 3 where the spring end 66 is shown seated in the latching slot 40.

A latch release bar 70 is mounted in sliding relation on the bolts 25 on the outside face of the frame plate 10'. The release bar 70 has a series of longitudinally spaced, elongate apertures 71, each with an end portion of reduced width, indicated at 72, into which the terminal ends 66 of the spring arms 63 extend with the spring arms 63 normally urging the release bar 70 to the right in FIGURE 1. The latch arms 63 are tensioned so that the end portions 66 seat in the apertures 72 and normally hold the release bar 70 in non-releasing positionA Any one of the plungers 22 may then be depressed and the end 66 of the associated latch arm 63 will be moved back in the slot 71 by engagement of the cam edge 42 with the same until the plunger 22 is depressed sufficiently to allow the spring end 66 to snap back into the latching notch 40 where it will remain until the release bar 70` is moved to the left in FIGURE l. In the form of the apparatus illustrated manual release of any or all the plungers 22 which have been depressed is provided for by co-operation between the end plunger 22 (FIGURES 2 and 3) and a pin 73 provided on the latch bar 70 which extends through an aperture 67 and normally seats in the notch 41 in the plunger 22. When the plunger 22' is depressed, the cam edge 42 engages the pin 73 and forces the release bar 70 to the left in FIGURE 1 which pulls each of the spring arms 63 to the left sufficiently to move the end members 66 out of the latching slots 40 allowing the plungers 22 to be raised by the springs 55. The cam slot 41 in the plunger 22 and the pin 73 are located relative to each other so that the pin 73 rides on the inclined cam edge 42 and the plunger 22 is not held in depressed position but returns to its uppermost position when pressure on it is removed. It may control a circuit if desired by having it equipped with an actuator 18 and a contact assembly 30.

An alternate means for actuating the release bar 70 is shown in FIGURE 3 where a solenoid 80 is attached by means of a bracket 81 to the frame plates 10 and 10 and provided with a hingedly mounted plate 82 at the bottom end on which there is an upstanding arm 83 positioned so that the upper end thereof bears against the end of the release bar 70. When the solenoid 80 is actuated the plate 82 is hinged upwardly and the arm 83 moves the release bar 70 to the left which moves the spring arms 63 with it and disengages the spring arms 63 which are in latching engagement with any of the plungers 22 which have been depressed.

The operation of the apparatus of` FIGURES 1 to 5 will be apparent from the description thereof. Each of the plungers 22 may be operated to control a separate circuit or a part of a circuit and any number of the plungers 22 may be depressed to actuate the associated switches 30 with all of the plungers `being released when the latch release bar 70 is actuated so as to draw the spring arms 63 to non-latching position.

A modified form of the apparatus is illustrated in FIG- URE 6. In this form of the apparatus a modified spring latch arm 93 is employed and also a modified latch release bar 94. The other elements or parts of the apparatus may remain the same as in the form illustrated in FIG- URES 1 to 5. The spring latch arm 93 is bent as shown in FIGURE 6 so that a portion 95 intermediate the ends extends vertically and lies along the face of the plate 10. The intermediate portion 95 is disposed between the projecting ends of adjoining guide members which in this form of the apparatus are assembled in the apertures 16, 16 so that the longest sides thereof are on the side of the frame on which the spring latch arms 93 are mounted.

The bottom and top end portions 96 and 97 extend diagonal relative to the middle portion 95 and a top terminal end portion 98 extends at right angles to the plane of the plates 10 and 10 and projects through an aperture 67 for engagement in a notch 41 of the associated plunger 22. The spring arms 93 are tensio'ned to co-operate with the plungers 22 to latch the same in the depressed position, in the same manner as the spring arm 63 in the form of the apparatus shown in FIGURES 1 to 5. The release bar 94 has protuberances 100 on the face which is opposed to the outside face of the frame plate 10 which protuberances engage a top portion of each of the spring arms 93 and in the non-releasing or inoperative position of the bar 94 permit the end portions 98 to engage in the notches 41 and move into the latching notches 40 when the plungers 22 are depressed. The release bar 94 may be moved to the left in FIGURE 6, either manually or automatically, to withdraw the ends 98 of the spring arms 93 from latching engagement in the notches 40 by the same manual or electromagnetic operation as shown in FIG- 6 URES l to 5 with a push rod 22 being provided to cooperate with a pin 101 on the release bar or with an electromagnetic operated arm engaging the release bar 94 to move it to release position.

The spring latch arms and release bar arrangements shown herewith may be readily adapted for use in other' multiple station switch arrangements and the use thereof is not limited to the accumulative type switch which is illustrated.

While paricular materials and specific details of construction have been referred to in describing the switch assemblies which are illustrated it will be understood that other suitable materials and equivalent structural details may be resorted to within the spirit of the invention.

I claim:

1. A multiple push button switch having a supporting frame member with means thereon forming guide tracks, switch actuators mounted for movement on said guide tracks between switch actuating and non-actuating positions, switch means mounted on said supporting frame and disposed in the path of said actuators for operation by the same, reciprocable plunger members connected with said actuators and operable to move said actuators to switch actuating position, inserts forming guides for said plunger members mounted on said supporting frame member in spaced relation to said switch actuators, resilient means urging said switch actuators toward a non-actuating position, said plunger members having latch arm engaging means, elongate spring latch arms mounted adjacent each plunger member and having free end portions biased into resilient engagement with said plunger latch arm engaging means, each plunger member moving its associated latch arm to non-latching position as the plunger member is depressed until the plunger member reaches switch actuating position where the free end of the latch arm swings into latching engagement with said plunger latch arm engaging means so as to hold the plunger member against return movement.

2. A multiple push button switch having a supporting frame member with means thereon forming guide tracks, switch actuators mounted for movement on said guide tracks between switch actuating and non-actuating positions, switch means mounted on said supporting frame and disposed in the path of said actuators for operation by the same, reciprocable plunger members connected with said actuators and operable to move said actuators to switch actuating position, inserts forming guides for said plunger members mounted on said supporting frame member in spaced relation to said switch actuators, resilient means urging said switch actuators toward a nonactuating position, said plunger members having latch arm engaging means, latch arms mounted adjacent each plunger and having portions which are engageable with said plunger, each plunger moving its associated latch arm to non-latching position as the plunger is depressed until the plunger reaches switch actuating position where the latch arm is disposed in latching engagement with said plunger so as to hold the plunger against return movement, said latch arms being in the form of a length of wire-like material with the lower end thereof secured on the frame member and an upper end portion disposed to engage the associated plunger.

3. A multiple push button switch a set forth in claim 2 and said latch arms each being formed from a length of wire having substantial resiliency.

4. A multiple push button switch as set forth in claim 3 and said latch arms each having the lower end thereof fixed on the frame member and the upper end thereof turned at an angle transversely of the plane of the associated plunger member and disposed to engage the side edge of said plunger member.

S. A multiple push button switch as set forth in claim 1 and means to move said latch arms out of engagement with said plungers so as to relea-Se said plungers for return to non-switch actuating position.

6. In a multiple push rod switch having a supporting frame member with means thereon forming guide tracks, switch actuators mounted for movement on said guide tracks between switch actuating and non-actuating positions, switch means mounted on said supporting frame and disposed in the path of said actuators for operation by the same, reciprocable plate-like push rods carrying said actuators, guides for said push rods disposed on said supporting frame member in spaced relation to said switch actuators, resilient means urging said switch actuators toward a non-actuating position, said push rods having notches in their side edges, spring latch arms mounted adjacent the push rods and having end portions which are free to swing to positions where they are engageable in Certain of said notches, each push rod having a cam portion engaging the end portion of the associated latch arm so as to move the latch arm end portion aside when the push rod is depressed until the push rod reaches switch actuating position where the latch arm end portion is freed to spring into engagement in a notch so as to hold the plunger against return to non-actuating position.

7. In a multiple push rod switch as set forth in claim 6 and at latch arm release means which is actuated to move the latch arms out of engagement in said notches so as to free the push rods -which have been depressed for Ireturn to non-switch actuating positions.

8. In a multiple push rod switch as set forth in claim 6 and a common release bar for said push rods which is disposed in sliding relation on said supporting frame, which release bar has a portion engaging each spring arm adjacent the free end portion thereof so that in one direction of movement of said release bar the free ends of the spring arms are moved out of engagement in said notches.

9. In a multiple push rod switch having a supporting frame member with means thereon forming guide tracks, switch actuators mounted for movement on said guide tracks between switch actuating and non-actuating positions, switch means mounted on said supporting frame and disposed in the path of said actuators for operation by the same, reciprocable plate-like push rods carrying said actuators, guides for said push rods disposed on said supporting frame member in spaced relation to said switch actuators, resilient means urging said switch actuators toward a non-actuating position, said push rods having notches in their side edges, latch arms mounted adjacent the push rods and having end portions which are engageable in certain of said notches, each push rod having a cam portion engaging the associated latch arm so as to move the latch arm aside when the push rod is depressed until the push rod reaches switch actuating position where the latch arm is freed to spring into engagement in a notch so as to hold the plunger against return to non-actuating position, said latch arms each having a vertically disposed intermediate portion and opposite end portions bent at an angle to the intermediate portion with the lowermost end portion ixed at its end on the supporting frame and with the uppermost end portion having its terminus bent into a transverse plane and disposed so as to resiliently engage in a notch in the edge of the associated push rod.

10. In a multiple push rod switch having a supporting frame member with means thereon forming guide tracks, switch actuators mounted for movement on said guide tracks between switch actuating and non-actuating positions, switch means mounted on said supporting frame and disposed in the path of said actuators for operation by the same, reciprocable plate-like push rods carrying said actuators, guides for said push rods disposed on said supporting frame member in spaced relation to said switch actuators, resilient means urging said switch actuatons toward a non-actuating position, said push rods having notches in their side edges, latch arms mounted adjacent the push rods and having end portions which are engageable in certain of said notches, each push rod having a cam portion engaging the associated latch arm so as to move the latch arm aside when the push rod is depressed until the push rod reaches switch actuating position where the latch arm is freed to spring into engagement in a notch so as to hold the plunger against return to non-actuating position, a latch arm release means which is actuated to move the latch arms out of engagement in said notches so as to free the push rods which have been depressed for return to non-switch actuating positions, said latch arm release means being a slidably mounted spring biased bar disposed on the supporting frame and having means thereon engaging uppermost portions of said latch arms so as to move said portions of said latch arms out of engagement in the notches in said push rods when said bar is moved to one position thereof.

11. A multiple station switch having a supporting frame with means thereon forming guide tracks, switch actuators mounted for movement on said guide tracks between switch actuating and non-actuating positions, switch means mounted on said supporting frame and disposed in the path of said actuators for operation by the same, plate-like reciprocably mounted plunger members carrying said actuators between switch actuating and nonactuating positions, guides for said plunger members mounted on said supporting frame in spaced relation to said switch actuators, resilient means urging said switch actuators toward a non-actuating position, said plunger members having notches in their side edges, elongate spring latch arms mounted adjacent each plunger member and having free end portions which are biased into engagement in certain of said notches, each plunger member having a cam formation on its edge for moving the end portion of its associated latch arm aside as the plunger member is depressed until the plunger member reaches switch actuating position where the free end of the latch arm springs into engagement in a latching notch so as to hold the plunger member against return movement to a non-switch actuating position, said plunger members and latch arms being arranged so that any number of plunger members may be depressed to switch actuating position, and held by said latch arms, and means for disengaging the spring arm end portions and releasing said depressed plunger members for return to non-switch actuating positions.

12. A multiple station switch as set forth in claim 11 and said means for releasing the depressed plunger members comprising a bar member slidably mounted on said supporting frame and having protuberances engaging said latch arms adjacent the free end portions of said latch arms so that upon predetermined movement of said bar member said latch arms are moved to free depressed plunger members, and co-operating cam track and follower means on said bar member and one of said plunger members for moving said release bar in a direction to release depressed plunger members.

13. A multiple station switch having a supporting frame with means thereon forming guide tracks, switch actuators mounted for movement on said guide tracks between switch actuating and non-actuating positions, switch means mounted on said supporting frame and disposed in the path of said actuators for operation by the same, platelike reciprocably mounted plunger members carrying said actuators between switch actuating and non-actuating positions, guides for said plunger members mounted on said supporting frame in spaced relation to said switch actuators, resilient means urging said switch actuators toward a non-actuating position, said plunger members having notches in their side edges, latch arms mounted which are biased into engagement in certain of said notches, each plunger having a cam formation on its edge "for moving its associated latch arm aside as the plunger is depressed until the plunger reaches switch actuating position where the free end of the latch arm engages in a latching notch so as to hold the plunger member against return movement to a non-switch actuating position, said plunger members and latch arms being arranged so that any number of plunger members may be depressed to switch actuating position, and held by said latch arms and means for releasing said depressed plunger members for return to non-switch actuating positions, said means for releasing said plunger members comprising a release bar slidably mounted on said supporting frame, means on said release bar engaging the end portions of said latch arms for moving said latch arms out of said latching notches upon predetermined movement of said release bar, one of said plunger members having a cam track on one edge thereof and means on said release bar constituting a cam follower disposed for engagement with said cam track when said one plunger member is depressed so as to move said release bar in a direction to disengage said latch arms and release depressed plunger members.

References Cited UNITED STATES PATENTS 2,831,075 4/1958 Dumke et al. 2,935,577 5/1960 Dumke et al. 20D- 18 3,271,530 9/1966 Wirsching.

ROBERT K. SCHAEFER, Primary Examiner J R. SCOTT, Assistant Examiner PRINTER'. TRIM l n.

UNITED STATES PATENT OFFICE Patent No. 3;)"871176 Inventor(s) Glenn M. Stout Dated December 30, 1969 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 29, delete substitute illustrated Column 3, line 16, delete substitute positioned Column 4, line 28, delete substitute depressed Column 6, line 63, delete Column 7, line 2M, delte Column 8, line 70, after "illustrtaed" and "postioned'I and each plunger and having free end portions

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