US3080720A

US3080720A - Remote control switch operating device

Info

Publication number: US3080720A
Application number: US38161A
Authority: US
Inventors: William T Downs; Arthur H Ryan
Original assignee: Simmons USA Corp
Current assignee: Simmons USA Corp
Priority date: 1960-06-23
Filing date: 1960-06-23
Publication date: 1963-03-12
Anticipated expiration: 1980-03-12

Description

w. T. DoWNs ETAL 3,080,720

REMOTE CONTROL SWITCH OPERATING DEVICE March l2, 1963 4 Sheets-Sheet 1 Filed June 25, 1960 NVENTORS4 z/f F 477, 7 BY a# y March 12, 1963 w. T. DOWNS ETAL 3,080,720

REMOTE CONTROL SWITCH OPERATING DEVICE Filed June 23, 1960 4 Sheets-Sheet 2 INVENTORS. .Paf/ans" March 12, 1963 w` T. DowNs ETAL 3,080,720

REMOTE CONTROL SWITCH OPERATING DEVICE Filed June 25, 1960 4 sheets-sheet 3 Nw. NR Nm.

w. T. DOWNS ETAL 3,080,720 REMOTE CONTROL SWITCH OPERATING DEVICE March 12? 1963 4 Sheets-Sheet 4 Filed June 23, 1960 United States Patent REMOTE CONTROL SWITCH OPERATING DEVICE William T. Downs, Detroit, and Arthur H. Ryan, Farmington, Mich., assignors, by mesne assignments, to Simmons Company, New York, N.Y., a corporation of Delawarey Filed June 23, 1960, Ser. No. 38,161 5 Claims. (Cl. 60-545) This invention relates to remote control devices for operating switches, and particularly to a remote control switch operating device which is extremely flexible and lacking in spark producing materials.

In many places it is hazardous to operate switch equipment in view of the presence of gases and' other explosive substances which may be inadvertently ignited. One example is a hospital bed Where, when an oxygen tent is employed, it is placed over a portion of the patient in the area in which the switch mechanism would be placed. The opera-tion of switches beneath the oxygen tent would be hazardous from an explosive and fire standpoint since materials which `are not overly combustible in la normal atmosphere could 4be easily ignited by a spark produced by such a switch in the oxygenrich atmosphere within the tent. To avoid .these hazards and hazards in other places where gases may be present and switches -mus-t Ibe operated, the device of the present invention has been developed. This comprises a body having la plurality of plungers 4which m-ay be held in the hand or fixed to a point which is readily accessible. 'Ihe plungers ladvance fluid through tubes which are contained within a flexible sheath which Iis clamped to a receptacle containing switches which are operated selectively conforming to the plunger depressed by the operator. A plurality of plungers are provided in the body depressed by an embossed cam on a tiltable cap mounted in the outer end of the body after being rotated to one of a plurality of positions. Notch means may be provided over which the cap supporting mechanism ratchets to be lock-ed in the selected position at which the 'cap is tilted to have the embossed cam engage the selected plunger Vfor deecting it `downwardly 4and advancing its head into an associated chamber. The head displaees a substantial amount of liquid which may be water or water containing antifreeze material if the device is to be operated in an atmosphere of low temperature, or any -other duid known to be suitable for dow within the tubes may be employed. The material in which the lower portion of the chambers is disposed has small tubes extending therefrom and connected to exib-le tubes of small internal diameter.

Any number of plungers and tubes may be employed; in the example herein illustrated, ten such tubes are utilized lfor actuating different swi-tches to produce a variety of operations. The tubes extend Vfrom the chambers and the body through a exi-bie metal braided sleeve which is enclosed in a protective outer flexible tube, permitting the tube assembly to be bent without changing the operating characteristics of the device. 'I'he outer tube extends into a clamp on :a receptacle and the tubes of small diameter contained therein are joined to small metal tubes extending from chambers within -a body secured within the receptacle. The latter chambers contain plungers which are moved outwardly when the fluid moves into the latter chambers through the deliection of a plunger in the remotely :located body. The plungers in the receptacle operate pivoted arms and move lthem into engagement with switches which control solenoids, motors, sequence switches and the like lfor producing remote op eration of various elements.

In the hospital bed referred t-o above, the switches may l f' 3,080,720 C@ Patented Mar. 12, 1953 operate solenoid clutches for producing the up and down movement of the bed, the movement of the head portion, the central portion and/or the leg portion. Additional switches may control :a nurses call, the operation of a radio or television set, the opening and closing of draperies and the like. The actual elements which are to be operated vand the motors, solenoids, sequence switches and .the like which are to be actuated lform no part of the present invention.

Accordingly, the main objects of the invention are: to provide a remote control device for actuating switches which is flexible and which is sparkproof; to provide an adjustable cap in a body which is attached to a flexible sleeve containing Ia plurality of tubes in each of which fluid is advanced by the movement of an associated plunger to advance -another plunger at the remote end of the tubes; to have one plunger moved by .the advancement yof a fluid 4in a tube by a second plunger .th-rough the tilting of a cap to have the first plunger move an arm to engage and operate a switch; to provide a receptacle with a plurality of pivoted arms, one or more of which is actuated by a plunger for engaging and operating switches in response Ito the operation of -a remote plunger which forces a liquid through a tube to actuate the receptacle plunge-r, and, in general, to provide a remote control device for operating switches which is simple in construction, positive in operation and economical of manu-facture.

Other objects and features of novelty of .the invention Will be specifically pointed out or will become apparent when referring, for =a better understanding of the invention, to the following description taken in conjunction with .the accompanying drawings, wherein:

FIGURE l is a broken plan view of a switch receptacle and a remote operating device joined by a flexible element embodying features of the present invention;

FIG. 2 is an enlarged sectional view of the structure illustrated in FIG. 1, taken on the line 2 2 thereof;

FIG. 3 is a sectional view of the structure illustrated in FIG. 2, taken on the line 3 3 thereof;

FIG. 4 is a sectional view of the structure illustrated in FIG. 2, taken on the line 4 4 thereof;

FIG, 5 is a sectional view of the structure illustrated in FIG. 2, taken on the line 5 5 thereof;

FIG. 6 is a broken sectional View of the structure illustrated in FIG. 5, taken on the line 6 6 thereof;

FIG. 7 is a broken View of structure, similar to that illustrated in FIG. 2, with a plunger illustrated as being deflected;

FIG. 8 is an open view of the receptacle portion of the v device illustrated in FIG. 1;

FIG. 9 is an enlarged sectional view of the structure illustrated in lFIG. y8, taken on the line 9 9 thereof;

FIG. l0 is an enlarged sectional view of the structure illustrated in FIG. 8, taken on the yline 10-10' thereof;

FIG. l1 is a view of structure, similar to that illustrated FIG. 10, showing another form thereof;

FIG. v12 is a plan view of a control device, similar to that illustrated -in FIG. 3, showing another form thereof; and

FIG. 13 is a sectional View of the structure illustrated in FIG. 12, taken on the line 13 13 thereof.

The remote control device of the present invention for actuating switches comprises a receptacle 11 containing a plurality of switches and fingers 12 by which electric contact is made, with the switches disposed in a plurality of circuits which are connected to elements controlled by the device. A control element 13, from which a particular switch to be actuated is selected, contains a body portion 14 and a cap 15 which is rotatably adjustable relative to the body portion and tiltable relative to the axis thereof. A sleeve 16 encloses a plurality of liquid conducting tubes 17 and a braided metal sheath 18 to prevent damage thereto while providing liexibility between the body 14 and receptacle 11 so that the switches may be actuated from different locations of the control element. The body 14 of the control element is made from a central section 20, an outer section 21 threaded thereto, and a bottom section 22 secured to the central section by a plurality of screws 23. The central section 20 and the bottom section 22 have a plurality of

recesses

24 and 25 therein disposed in mated relation to each other to form chambers. In the present arrangement, ten chambers are illustrated, but it is to be understood that any number could be provided.

A flexible element 26 of rubber like material seals the area between the

sections

20 and 22 and has embossed therein cups 27 which extend Within the recesses Z4 in the central section 20. Plungers 28 have enlarged headsl 29 which extend within the telescopedV end portions of the embossed cups 27. A finger 31 extends from each of the heads 29 outwardly within the area of the outer section 21 of the body 14. The cap 15 encloses the opening in the outer section 21, secured in position by a boss 33 which is pivoted to a -bifurcated head 34 of a rod 35. The opposite end of the rod extends within a washer 36 to which it is secured by a pin 37. The inner edge of the washer 36 is provided with teeth 38 which mate with notches 39 between teeth 41 in the central section 20 of the body 14. A spring 42 urges they cap 15 outwardly of the opening in the outer section 21 of thebody 14 and thereby retains the teeth 38 within the notches 39'while permitting the camming of the teeth 38 over the teeth 41 when the cap 15 is rotated. The `outer surface of the cap 32 has a central embossment 43 which is engageable by the fingers of the operator for turning the cap from one position to another.

The inner face of the cap is provided with embossed cams 44 which are diametrically disposed across the cap in alignment with the embossment 43 on the outer surface thereof. When the cap is rotated to a desired position by the operator, it may be tilted along the plane of the embossment 43 either forwardly or rearwardly for producing an operation of a device in one direction or lin the opposite direction. This may be true of any of the ten stations, at any one of which it is possible to operate a device and thereafter to return it to its initial position. By tilting the cap forwardly and rearwardly, forward and reverse operations are produced with a single setting of the cap.

The ten recesses 25 have ten metal tubes 40 of a small diameter communicating therewith and with the flexible tubes 17 which extend thereover. The fluid within the chambers formed by the

recesses

24 and 25 fills the

tubes

40 and 17 in a solid column so that any movement of the fluid from a chamber will cause the fiow of rfluid through the associated

tube

40 and 17. v

Since there are ten chambers, there will be ten tubes 17 extending from the body 14 and these are confined in a small cross-sectional area at the end of the closure 45 secured to the section 22 by a plurality of screws 46. The tubes 17 may be of any length depending upon the distance the receptacle 11 is to be disposed from the body 14. The tubes 17 are disposed within the woven metal sheath 18 whichshields the tubes and grounds any static which may develop through the relative movement between the tubes when the assembly is flexed. Over the woven metal sheath, a sleeve 48 of wear-resistant plastic material is provided for encasing the plurality of tubes 17 and sheath 18. The sleeve 48 is slid through the small end of the element 45, and the sheath 47 and a collar 49 disposed therewithin form an enlargement which wedges within the small end of the element 45. The opposite end of the sleeve 48 is clamped within a collar 51 at an inlet opening to the receptacle 11.

The plurality of tubes 17 arek sealed to the ends 52 of 4 .I metal tubes 53 which extend through 4a plate 54 having five recesses 55 therein. A block 56 has five cavities 57 therein -aligned with the recesses 55 in the plate'54, with a sealing element 58 of resilient material disposed between the abutting faces of the block 56 and plate 54. Five embossed cups S9 rare disposed within the recesses 55 and cavities 57, telescoped over the heads 61 of the plungers 62 having lingers 63 extending from the top of the block. The block and plate are secured together by a plurality of screws 64 insealed relation to each other. This assembly is indicated by the numeral 65, and a similar and adjacently located assembly is indicated by the numeral `66. On opposite sides of the blocks, shafts 67 and 68 are mounted for pivotally supporting fingers 69, 71 and 72 kon the rod 67, and 73, 74 and 75Y on theV rod 68, which latter fingers have been swung backwardly to extend upwardly within the receptacle. A finger 76 extends from a plate 77 having projecting ends 78 pivoted on the rod 67 in positionto be actuated when any one of the fingers 69, 71 land 72 are pivoted upwardly. A finger 81, similar to the finger 76, is supported by a cross plate 82 on arms 83 pivoted 0n the shaft 68. Groups of washers 84 may be provided on the shafts for spacing the lingers in predetermined relation to each other.k

Fingers 85 and S6 are pivotally mountedon the shafts 67 and 68 respectively, the ngers being of greater width for operating a pair of switches simultaneously.

The switches 88, 89 and 91 are actuated by the fingers 69, 71 and 72 or 73, 74 and 75. When one or more of the switches 88, 89 and 91 kare operated by a finger 69, 71 or 72, the motor switch 92 is energized for driving in one direction by the finger 76. ShouldV any one of the switches 88, 89 or 91 be actuated by a finger 73, 74 or 75, then the motor is energized in the opposite direction by the actuation of the Vswitch 93 by the finger 81. The finger 85 actuates the two

switches

94 and 95 while the finger 86 operates the two 4switches 96 and 97, onek of the two switches actuatingy the motor. A finger 98 on the shaft 68 actuates a switch 99 anda similar finger could be mounted on the shaft 67 for operating a switch similar to the switch 99.

When -a plunger 28 is deflected by the cam 44 in the cap 15, as illustrated in FIG. 7, the fiuid withinY the associated chamber is moved therefrom through a tube 17 into a chamber in 4the plate 54 to cause the finger 63 of a plunger 62 to move outwardly from the top of the block 56. The linger 63 will actuate a pivoted finger on the shaft 67 or 68 toY have the lianged ends 101 thereof engage one or more switch arms to actuate one or more of the switches. It will thus be seen that the actuation of the switch will take place at a remote point from the body 14 for safety or for other reasons. While it has been mentioned that the remote operating device has a particular advantage for use with a hospital bed having a motor drive and switches which can produce arcing, it is to be understood that theV bed was mentioned only by way of example and is not to be considered limiting.

In FIG. ll the recesses `55 have rubber embossed cups i102 extending therein from a fiat sealing element 103 which is vulcanized to the fiat sealing element V104 containing the cups 59 which are Ialigned with the oups y102. The cups 102 have tubular extensions 105 thereon into which vthe adjacent end-s of the tubes 17 extend and are adhered thereto in sealed relation therewith. The use of the :second sealing element 103 having the cups 1102 thereon provides a completely enclosed liquid system which is leakproof yand evaporation-proof. A similar sealing element y103 is employed between

sections

20 and 22 of the control element 13. The huid is sealed within the cups 27 and `102 and is moved therefrom when a plunger 28 in the body 14 is axially advanced. The fluid will be advanced through a tube 17 into the connected cups 59 and 102 within the receptacle to axially advance a plunger 62 1 to operate ya switch.

.5 is illustrated, Ithat of the sliding type, embodying a rectangular housing 110, having an open bottom and the top web 111 which is provided with a longitudinally disposed central slot 112 having oppositely disposed notches 1-13 at spaced points therealong. A pair of blocks 114 |and 115 are secured together by screws 116 and retained in the bottom of the housing against a shoulder 117 therein by screws 118. The two blocks `114 and 115 contain rows of aligned recesses 55 and 57, respectively, and have disposed therebetween a pair of resilient sheets 103 and 104 containing cups 162. and 119. The two resilient sheets are secured together in sealed relationship at the mating pontions thereof in areas beyond the cups 16.2 and 119 which thereby form sealed chambers 121. The chambers have an extending tubular portion 122 in which the end 123 of a fiexible tube 124 extends and is secured thereto in sealed relation therewith. All of the tubes 124 extend from the forward end of the housing and outwardly therefrom within the flexible sheath 16 in the manner as hereinabove described with regard to the operating element 13.

The plungers 29 engage the cups 119 and deflect them within the chamber 121 and `force the fluid therein out of the tubes 1114 to operate plungers and elements in the receptacle 11 in the manner as pointed out above. An operating member 126 is slidable along a rod 127 which is Ialigned with the slot 112. The operating element 126 Ihas extending arms 128 and 1.29 which are aligned with the fingers 131 on the end of the plungers Z9 when located in alignment with a pair of the notches 113. The element 126 has an extending boss 132 at the bottom containing -a spring 133 yand a ball 134 which is urged from the end by the pressure in the spring. A slot 135 in the top central portion of the block 114 beneath the Irod .127 contains spaced laterally disposed arcuate slots 136 in the bottom portion in alignment with the notches 113 to position the arms 128 and 129 over the fingers 131 of the plungers 29. The notches 113 permit the element 126 to vberocked to the right or left, as illustrated in FIG. 13, so as to have one of the -ar-ms 128, 129 engage land operate one of the plungers. By this arrangement, the pair of aligned plungers cannot be operated Isimultaneously so that each must be operated independently of the other.v Additionally, a pair of push buttons -137 and 138 are illustrated in the housing 110 which may be used for various-purposes. For example, the push button 137 may be employed when defiected to advance a plunger 29 to operate a nurses call, while the push button 138 when pressed to advance a plunger 29 may be employed foroperating draperies to closed or open position, as may be desired. Both of the

push buttons

137 and 138 operate a finger 131 on a plunger for directing fluid through a conduit 139 out through the housing and flexible sleeve 16 to the receptacle for actuating an element to thereby produce the operations desired. I-t will be noted that the chambers l131 are completely sealed in the resilient sheets 103 and 104 when sealed together, or when the sheet 103 is eliminated and the sheet 104 is directly sealed to the `face of the block 114. The material of the block and the sheets 4163 and 104, being without pores, are thereby impervious to the passage of liquid Iand gas therethrough.

The remote control device thus provided is -fiexible, is not limited in length, and is operable in the presence of `an explosive gas without danger of ignition. Plungers are mounted in the body of a control element which advance columns of liquid in tubes communicating with plungers located at a remote point for selectively actuating elements which may be switches, valves, cams, levers and the like from ya point remote from the operator. The remote control device is illustrated -for raising the head portion, the central por-tion 'and the leg portion of a sectional bed and to raise the bed upwardly or downwardly as a unit. Additional plungers are provided for actuating switches for operating other elements such as for moving curtains to open and closed position, operating a signal to attract the attention of a nurse, and the like. In the ldevice herein illustrated, ten plungers are utilized, each plunger, when longitudinally moved, advancing a column of liquid to move a plunger axially at the end of the liquid column -to thereby provide -a fiexible force applying means between each pair of plungers. The control element contains the one set of plungers, any one of which may be longitudinally moved by a selector element which may be rotated longitudinally, moved to a tilted position, or otherwise mounted -for selectively actuating one plunger while locking the other. The metal sheath grounds any charges which may form in the sleeve yabout the tubes therein and may be a cable wire or other fiexible conducting elemen-t. The sleeve 48 is made of` wear resistance plastic, rubber or other fiexible material. The flanged ends 101 of the switch actuating finger may be made of insulating material, have insulation applied thereto and/or engage an insulated actuating finger o-f the switch with which it is associated.

What is claimed is:

1. A remote control device comprising a plurality of independent hydraulic systems; each of said systems including means defining an elongated passageway, a first and second plunger projecting into the opposite ends of said passageway and being adapted tor axial movement inwardly and outwardly thereof, a first and second fluid-impermeable flexible sealing element disposed within said passageway adjacent each o-f said first and second plungers, said first sealing element being efiective to bias said first plunger in a direction outwardly of said passageway and said second sealing element being effective to bias said second plunger inwardly of said passageway, and a liquid filling the space within said passageway intermediate said fiexible sealing elements so as to hydraulically connect said plungers where-by inward movement of said first plunger causes outward movement of said second plunger; and means for selectively actuating one of said systems comprising a body containing said fi-rst plungers disposed with their longitudinal axes parallel to one another, Iand a -shitable cap on said body having a cam selectivelyengageable with each of said first plungers so as to cause movement thereof upon predetermined movement of said cap.

2. A remote control device comprising a plurality of independent hydraulic systems; each of said systems including means defining an elongated passageway, a first land second plunger projecting into the oppos-ite ends of said passageway and lbeing adapted for axial movement inwardly and loutwardly thereof, a first and second cupshaped fiuid-impermeable fiexible sealing element disposed within said passageway adjacent each of said rst and second plungers, said first sealing element being effective to bias said first plunger in a direction outwardly of said passageway and said second sealing element being connected to said second plunger and being effective to bias said second plunger inwardly of said passageway, and a liquid filling the space within said passageway ntermediate said -fiexible sealing elements so as to hydraulically connect said plungers whereby inward movement of said first plunger causes outward movement of sa-id second plunger; and means for selectively actuating one of said systems co-mprising a body containing said first plungers disposed with their longitudinal axes parallel to one another, and a shiftable cap 4on said body having a cam selectively engageable with each of said first plungers so as to cause movement thereof upon predetermined movement of said cap.

3. A remote control device comprising a plurality of independent hydraulic systems; each of said systems including wall means defining an elongated passageway, a first and second plunger projecting into the opposite ends of said passageway and being adapted for ax-ial movement inwardly and outwardly thereof, a first and second cup-shaped fiuidimpermeable flexible sealing element disposed within -said passageway adjacent each of said first 'and second plungers and substantially coaxial therewith, `each of said sealing elements having side walls which include an extension turned inwardly so as to parallel the Wall defining said passageways, said extension including an offset rflange secured to the walls of said passageway, said first sealing element being effective to bias said first plunger in a direction outwardly of said passageway and said second sealing element being connected to said second plunger and being effective to bias said second plunger inwardly of sa-id passageway, and a liquid filling the space within said passageway intermediate said fiexible sealing elements so as to hydraulically connect said plungers whereby inward movement of said first plunger causes outward movement of said second plunger; and means for selectively actu-ating one of'said systems'comprising a body containing said first plungers disposed with their longitudinal axes parallel to one another, and a shiftable cap on said body having a cam selectively engagea-ble with each of said first plungers Vso as to` cause movement thereof upon predetermined movement of said cap.

4. A remote control device comprising :a plurality of independent hydraulic systems, each of said systems including wall means deiining an elongated passageway, a first `and second plunger projecting into the opposite ends of said passageway and being adapted for axial movement inwardly and'outwardly thereof, a first and second cup-shaped huid-impermeable fiexible sealing element disposed within said passageway .adjacent each of said first and second plungers and substantially coaxialY therewith, each 'of said sealing elements having Iside walls which include an extension turned inwardly so as to parallel the wall defining said passageway, said extension including an offset flange secured to theL walls of said passageway, said 'first sealing element being effective to bias said first plunger in a direction outwardly of said passageway and said second sealing element being connectedV to said second plunger and being effective tobias said second plunger inwardly of said passageway, and a liquid filling .the space'within said passageway intermediate said -fiexi-ble sealing elements so as to hydraulically connect said plungers whereby inward movement ofk said first plunger causes outward movement ofjsaid second plunger; and means for selectively actuating one of said systems comprising a body containing said first plungers uniformly arranged therein in arcuate configuration with their longitudinal axes parallel to one another, a shiftable cap rotatably mounted on said body, and a cam on said cap selectively `eng-ageable with each of said rst plungers vso as to cause movement thereof upon predetermined movement of said cap.'

5. A remote control device comprising a plurality of independent hydraulic systems, each of said systems including wall means `defining an elongated passageway, a first and second plunger projecting into the opposite ends of said passageway and being adapted for axial movement inwardly and outwardly thereof, a firstand second cup-shaped fluid-impermeable flexible sealing element disposed'within'said passageway adjacent each of said first and second plungers and substantially coaxial therewith, each of said sealing elements having side walls which include an extension turned inwardly so as to par- .allel the wall defining said passageway, said extension including an offset iiange secured `to the walls of said passageway, said first sealing element being effective to bias said first plunger in a direction outwardly of said passageway and said second sealing element being connected to said second plunger and being efective to bias -said second plunger inwardly of said passageway, and a yliquid filling the space within'said passageway intermediate said flexible sealing elements so as to hydraulically connect said plungers whereby inward movement of said first plunger causes outward movement of said second plunger;v and means for `selectively actuating one of said systems comprising `a body containing said first .plungers uniformly disposed therein in an arcuate conliguration with their longitudinal axes parallel to one another, a shiftable capi rotatably and pivotally mounted on said body, 4and a cam on said cap selectively alignable with eachof said first plungers, said cap being tiltable so as to Veffect engagement of said cam with an aligned iirst Vplunger so as to cause inward movement thereof.

Referencesv Cited in the file of this patent UNITED STATES PATENTS France Aug. 24, 1911

Claims

1. A REMOTE CONTROL DEVICE COMPRISING A PLURALITY OF INDEPENDENT HYDRAULIC SYSTEMS; EACH OF SAID SYSTEM INCLUDING MEANS DEFINING AN ELONGATED PASSAGEWAY, A FIRST AND SECOND PLUNGER PROJECTING INTO THE OPPOSITE ENDS OF SAID PASSAGEWAY AND BEING ADAPTED FOR AXIAL MOVEMENT INWARDLY AND OUTWARDLY THEREOF, A FIRST AND SECOND FLUID-IMPERMEABLE FLEXIBLE SEALING ELEMENT DISPOSED WITHIN SAID PASSAGEWAY ADJACENT EACH OF SAID FIRST AND SECOND PLUNGERS, SAID FIRST SEALING ELEMENT BEING EFFECTIVE TO BIAS SAID FIRST PLUNGER IN A DIRECTION OUTWARDLY OF SAID PASSAGEWAY AND SAID SECOND SEALING ELEMENT BEING EFFECTIVE TO BIAS SAID SECOND PLUNGER INWARDLY OF SAID PASSAGEWAY, AND A LIQUID FILLING THE SPACE WITHIN SAID PASSAGEWAY INTERMEDIATE SAID FLEXIBLE SEALING ELEMENTS SO AS TO HYDRAULICALLY CONNECT SAID PLUNGERS WHEREBY INWARD MOVEMENT OF SAID FIRST PLUNGER CAUSES OUTWARD MOVEMENT OF SAID SECOND PLUNGER; AND MEANS FOR SELECTIVELY ACTUATING ONE OF SAID SYSTEMS COMPRISING A BODY CONTAINING SAID FIRST PLUNGERS DISPOSED WITH THEIR LONGITUDINAL AXES PARALLEL TO ONE ANOTHER, AND A SHIFTABLE CAP ON SAID BODY HAVING A CAM SELECTIVELY ENGAGEABLE WITH EACH OF SAID FIRST PLUNGERS SO AS TO CAUSE MOVMENT THEREOF UPON PREDETERMINED MOVEMENT OF SAID CAP.