US3908685A

US3908685A - Pneumatically operated control device and parts therefor or the like

Info

Publication number: US3908685A
Application number: US405093A
Authority: US
Inventors: Edward N Caldwell
Original assignee: Robertshaw Controls Co
Current assignee: Robertshaw Controls Co
Priority date: 1973-10-10
Filing date: 1973-10-10
Publication date: 1975-09-30
Anticipated expiration: 1992-09-30

Abstract

A control device having a main lever pivotally mounted to a support that also carries a plurality of flexible diaphragms disposed in spaced aligned relation and parallel to the longitudinal axis of the main lever, certain of the diaphragms having diaphragm members operatively associated with the main lever to tend to cause pivoting movement of the main lever upon movement of the respective diaphragm operatively associated therewith. A control unit is carried by the support and is operatively associated with the main lever to be controlled by the pivoted movement thereof. A pair of secondary levers are each pivotally mounted to the support and are effectively engageable with the main lever to tend to pivot the main lever upon pivotal movement of the respective secondary lever, the remainder of the diaphragms being operatively associated with the secondary levers to tend to cause pivoting movement of the secondary levers upon movement of the remainder of the diaphragms. The secondary levers are disposed in aligned spaced relation relative to each other and are disposed parallel to the longitudinal axis of the main lever intermediate the main lever and the diaphragms to provide a compact control device.

Description

United States Patent Caldwell 1 1 Sept. 30, 1975 1 1 PNEUMATICALLY OPERATED CONTROL DEVICE AND PARTS THEREFOR OR THE Primary E.\-unzinerMartin P. Schwadron LIKE Assistant Eruminer-Abraham Hershkovitz [75] In entor: Edward N- Caldwe". Knox ille Attorney. Agent, or Firm-Candor, Candor & Tassone Tenn 57 ABSTRACT 1 1 Assigncci Roberlshaw Controls p y- A control device having a main lever pivotally Richmond- V1 mounted to a support that also carries a plurality of [22] Filed: Oct 10 1973 flexible diaphragms disposed in spaced aligned relation and parallel to the longitudinal axis of the main 1 1 pp 9104405393 lever, certain of the diaphragms having diaphragm members operatively associated with the main lever to 1521 US. (:1. 137/84; 74/101; 137/86 tend to Cause pivoting movemm f the main ever 511 im. c1. F1513 5/00; (305D 16/00 "P movement of the fespecnve dlaphrflgfn [58} Field of Search 92/48, 49 76, 99, 105 tively associated therew1th. A control unlt is carried R 5 the support and 1S operatively associated with the main lever to be controlled by the pivoted movement [56] References Cited thereof.dA pair of seconday levefrfs are each pivotzlaliy mounte tot esupport an aree ecnve engagea e UNITED STATES PATENTS with the main lever to tend to pivot the main lever 2,178,927 11/1939 Campbell 137/85 X upon pivotal movement thc respective secondary i 2 lever, the remainder of the diaphragms being opera- 6 i g Sorcng X tively associated with the secondary levers to tend to 2:747:595 5/l956 Dickey 137/86 X cause pivoting movement of the secondary levers 2304.877 9/1957 Rosenberg 137/85 X upon movement of the remamdcr of the diaphragmsl 185L043 53 Hutchinson u 137 3 The secondary levers are disposed in aligned spaced 2936,5831 5/1960 Turek et a]. 137/86 X relation relative to each other and are disposed paral- 3,245.425 4/1966 De eyer et 3 /8 101 to the longitudinal axis of the main lever intermedi- 334516l9 4/1966 KWUICT 137/35 X ate the main lever and the diaphragms to provide a 3302.879 2/1967 Good v. 137/85 X compact 1 device 3390,69? 7/1968 Schmitz et a1. 137/86 X 3749.306 7/1973 M011 et 111. 137/85 x 16 s. 5 Dr ng Figures BRARJCH 31mm. IO2$l6NAL 1 MAIN US. Patent Sept. 30,1975

Sheet 2 of 3 FIG.3

US. Patent Sept. 30,1975 Sheet 3 of3 3,908,685

FIG.4

PNEUMATICALLY OPERATED CONTROL DEVICE AND PARTS THEREFOR OR THE LIKE This invention relates to an improved pneumatically operated control device as well as to improved parts of such a control device or the like.

It is well known that pneumatically operated receiver-controllers have been provided wherein each receiver-controller will provide a varying branch signal from a pneumatic source in relation to changes in a pneumatic signal being directed to the receiver-controller. For example, the receiver-controller upon a change in the value of the pneumatic signal being directed thereto will operate a control device, such as a leak port arrangement, to vary a pilot signal for a relay structure that will change the branch pressure accordingly.

It has been found according to the teachings of this invention that such a pneumatically operated receivercontroller can be formed relatively compact and from relatively inexpensive parts by utilizing the features of this invention.

In particular, one feature of this invention is to provide a control device wherein the pivotally operated levers thereof are disposed in aligned spaced parallel relation and the flexible diaphragms for operating the respective levers are also disposed in aligned spaced relation parallel to the pivotally mounted levers whereby the overall size of the receiver-controller is relatively compact.

In particular, one embodiment of this invention provides a support means having a main lever pivotally mounted thereto and being provided with a longitudinal axis. A plurality of flexible diaphragms are carried by the support means and are disposed in spaced aligned relation and parallel to the longitudinal axis of the main lever, certain of the diaphragms having means operatively associated with the main lever to tend to cause pivoting movement of the main lever upon movement of the respective diaphragm operatively associated therewith. A control unit is carried by the support means and is operatively associated with the main lever to be controlled by the pivoted movement thereof. A pair of secondary levers are each pivotally mounted to a support means and are effectively engageable with the main lever to tend to pivot the main lever upon pivotal movement of the respectively secondary lever, the remainder of the diaphragms being operatively associated with the secondary levers to tend to cause pivoting movement of the secondary levers upon movement of the remainder of the diaphragms. The secondary levers are disposed in aligned spaced relation relative to each other and are disposed parallel to the longitudinal axis of the main lever intermediate the main lever and the diaphragm. The means of the diaphragm that are operatively associated with the main lever each comprises a diaphragm member carried by its respective diaphragm and having a U-shaped end that straddles a secondary lever so as not to act on the same while engaging the main lever to act on the same.

Accordingly, it is an object of this invention to provide an improved pneumatically operated control device or the like, the control devicehaving one or more of the novel features set forth above or hereinafter shown or described.

Another object of this invention is to provide improved parts for such a pneumatically operated control device or the like.

Other objects, uses and advantages of this invention are apparent from a reading of this description, which proceeds with reference to the accompanying drawings forming a part thereof and wherein:

FIG. 1 is a top view of the improved pneumatically operated control device of this invention.

FIG. 2 is a cross-sectional view taken on line 2-2 of FIG. 1.

FIG. 3 is a cross-sectional view taken on line 33 of FIG. 2.

FIG. 4 is an exploded perspective view of certain parts of the control device of FIGS. 1-3.

FIG. 5 is a schematic view illustrating the operating features of the control device of FIGS. 1-4.

While the various features of this invention are hereinafter described and illustrated as being particularly adapted to provide improved parts for the pneumatically operated receiver-controller, it is to be understood that the various features of this invention can be utilized singly or in any combination thereof to provide improved parts for other types of control devices and the like.

Therefore, this invention is not to be limited to only the embodiment illustrated in the drawings, because the drawings are merely utilized to illustrate one of the wide variety of uses of this invention.

Referring now to FIGS. 14, the improved control device of this invention is generally indicated by the reference numeral 10 and comprises a support means or housing means 11 formed from a plurality of

platelike parts

12, 13, 14 and 15 disposed in stacked relation and having

suitable sealing members

16, 17 and 18 disposed therebetween, all of the housing parts being thus secured together by a plurality of fastening means 19 as illustrated.

The sealing member 18 is provided with a plurality of spaced aligned

diaphragm portions

20, 21, 22 and 23 formed integrally therewith and hereinafter referred to as diaphragms 20-23, each diaphragm 20-23 being defined by an outer annular convolution 24 having an outer side 25 and an inner side 26 surrounding a substantially flat circular part 27 thereof having an outwardly directed locating and locking rib 28 formed in the center thereof and being substantially elongated as illustrated in FIG. 4.

The plate 15 of the housing 11 has a plurality of

cylindrical openings

29, 30, 31 and 32 passing therethrough in such a manner that when the plate 15 is disposed on top of the sealing member 18 in its assembled relation with the next adjacent plate 14, the cylindrical openings 2932 respectively receive the outer sides 25 of the convolutions 24 of the flexible diaphragms 20-23 therein to support such outer sides 25 of the convolutions 24 of the diaphragms 20-23 during their up and down movement relative to the

plates

14 and 15. The diaphragms 20-23 are adapted to cooperate with suitably formed recesses in the plate 14 to

form chambers

33, 34, 35 and 36 respectively being adapted to be fluidly interconnected by internal passage means 37 formed in the plate 14 for a purpose hereinafter described whereby it can be seen that when fluid under pressure is directed to any one of the chambers 33-36, the corresponding diaphragm 20-23 is adapted to move upwardly and when such fluid pressure is decreased, such diaphragm -23 is adapted to mov downwardly as will be apparent hereinafter.

A main lever or beam 38 is adapted to be pivotally carried by the housing means 11 by having a transverse V-shaped notch means 39 that is formed therein bear against knife edge means 40 of a fulcrum member 41 that straddles the lever 38 and is fastened to the housing 11 by the upper fastening means 19 as illustrated. The left-hand end 42 of the lever 38 is urged upwardly by a compression spring 43 having one end 44 bearing against the under side 45 of the lever 38 at the end 42 thereof and having the other end 46 thereof bearing against a spring retainer 47 threadedly disposed on a threaded adjusting member 48 that is carried by a central hub 49 that bears against a frame part 50, FIG. 3, that is held stationary by the frame means 11 whereby rotation of the threaded adjusting member 48 in a manner hereinafter described will vary the compression of the spring 43 and, thus, the force of the spring 43 acting on the end 42 of the lever 38 tending to cause the lever 38 to pivot in a clockwise direction about the fulcrum member 41 as will be apparent hereinafter.

The central hub 49 as illustrated in FIG. 3 has a pinion gear portion 51 disposed in meshing relation with a pinion gear 52 rotatably mounted to the frame part 50 by a shaft 53, the pinion gear 52 having an upper pinion gear 54 carried thereby and disposed in meshing relation with an internal ring gear portion 55 of an outer adjusting knob 56 urged into engagement with the frame part 50 by a compression spring 57 disposed between the hub 49 and the adjusting knob 56.

In this manner, when it is desired to increase the compressive force of the compression spring 43 acting on the lever 38 to tend to pivot the same in a clockwise direction, the operator rotates the knob 56 in the proper direction whereby the ring gear 55 thereof acts on the upper pinion 54 to rotate the same and such rotation of the upper pinion 54 causes the lower pinion 52 to rotate in unison therewith and through its meshing relation with the pinion portion 51 of the inner hub 49 cause the inner hub 49 to rotate in the direction that causes the threaded member 48 to tend to thread into the retainer 47 whereby the retainer 47 is moved axially upwardly on the rotating threaded fastening member 48 to cause the spring 43 to be further compressed between the retainer 47 and the end 42 of the lever 48. Conversely, reverse rotation of the knob 56 will through the

gear arrangement

55, 54, 52 and 51 cause the threaded member 48 to rotate in a direction to cause the retainer 47 to thread downwardly on the same and thereby move away from the end 42 of the lever 38 and thus decrease the compressive force of the spring 43 tending to rotate the lever 38 in a clockwise direction, such axial movement of the spring retainer 47 being limited by the configuration of the frame 11 as illustrated.

Therefore, it can be seen that it is a simple matter to adjust the range spring 43 for the lever 38 by merely rotating the control knob 56 in the desired direction to position suitable markings 58, FIG. 1, on the control knob 56 relative to a reference mark 59 on the support 11 as illustrated for the desired setting of the range spring 43.

The other end 60 of the lever 38 carries a threaded member or post 61 locked thereto by a suitable locknut 62 to control a control unit (not shown in FIGS. 1-4 but is schematically illustrated and indicated by the ref erence numeral 63 in FIG. 5) that comprises a flapper valve member 64 having a natural bias tending to close a leak valve port 65 in a manner well known in the art so that when the end of the lever 38 is moved downwardly relative to the housing 11 in a manner hereinafter described by the lever 38 being moved in a clockwise direction about the pivot point 41, the flapper valve member 64 is moved away from the. leak port to increase the amount of bleed through the leak port 65 for a purpose hereinafter described. Conversely, upward movement of the member 61 by the lever 38 being moved in a counterclockwise direction about the pivot point 41 permits the flapper valve member 64 to move closer to the leak port 65 and, thus, decrease the amount of fluid leakage out of the leak port 65 for a purpose hereinafter described.

A pair of

secondary levers

66 and 67 are pivotally carried by the housing 11 and respectively have the

ends

68 and 69 thereof pivotally mounted against rod or wire-

like fulcrum members

70 and 71 carried respectively by the plate 15 in the manner illustrated in FIG. 2 adjacent post means 72 and 73 of the housing plate 14 that pass respectively through

suitable openings

74 and 75 in the plate 15 and are received through

suitable openings

76 and 77 respectively provided in the

ends

68 and 69 of the

levers

66 and 67 as illustrated, the post 73 further projecting through a locating opening 78 formed in the main lever 38 to facilitate the assembly of the various parts of the control device 10 together.

A pair of appropriately shaped

slide members

79 and 80 are respectively carried in a slot 81 formed through the main lever 38 with the

slide members

79 and 80 respectively carrying ball abutment means 82 and 83 respectively adapted to engage against the

levers

66 and 67 to provide effective adjustable moment arm relation for the pivoting movement of the

levers

66 and 67 acting on the main lever 38 to cause pivoting movement of the main lever 38 as will be apparent hereinafter.

Each diaphragm 20-23 has a diaphragm button or

member

84, 85, 86 and 87 therefor and being so constructed and arranged that each diaphragm member 84-87 has a substantially cylindrical or disc-like part 88 for being received within and guided by the convolution 24 of the respective diaphragm 20-23 and is provided with a recess 89 in a lower surface 90 thereof to receive the locking and locating rib means 28 in the manner illustrated in FIG. 2 whereby the diaphragm members 84-87 are properly oriented relative to the diaphragms 20-23 and have the cylindrical portions 88 thereof adapted to be guided and supported by the inside surface 26 of the convolutions 24 as illustrated during up and down movement of the diaphragms.

The

diaphragm members

84, 87 are each substantially U-shaped at the upper ends thereof to define two spaced-

apart legs

91 and 92 that are adapted to respectively straddle the respective

secondary lever

66 or 67 and engage against the main lever 38 at the under surface 45 thereof, the legs 91 having two hemispherical projections 93 thereon whereas the legs 92 have a single hemispherical projections 93 thereon so that the

diaphragm members

84 and 87 each makes three point contact with the underside 45 of the main lever 38.

The

diaphragm members

85 and 86 respectively have a T-shaped projections 94 extending from the upper surfaces thereof which are adapted to have their legs 95 respectively received in notches 96 formed in the adjacent ends 97 f the

levers

66 and 67 as illustrated in FIG. 2 whereby the cross members 98 of the T-shaped projections 94 are adapted to extend over the upper surfaces of the respective levers 66 and67 as illustrated in FIG.2. In this manner, upward-movement of the dia phragm members 85 and 86 'will through the upper rounded ribs 99 thereof engage against'the underside of the

levers

66 and 67 to cause counterclockwise pivoting of the lever 66 and clockwise pivoting of the lever 67 on the

respective pivot pins

70 and 71 whereas downward movement of the

diaphragm members

85 and 86 will through the T-shaped projections 94 thereof cause the

levers

66 and 67 to have the ends 97 thereof moved downwardly therewith as the lever 66 will pivot in a clockwise direction on the pivot pin 70 and the lever 67 will pivot in a counterclockwise direction on the pivot pin 71.

Therefore, it can be seen that the control device 10 of this invention is adapted to be formed of a plurality of relatively simple parts that can be dropped in place in substantially the manner illustrated in FIG. 4 to form the completed device 10 with the diaphragms 20-23 being adapted to be disposed in spaced aligned relation and parallel to the longitudinal axis of the main lever 38 and with the intermediate

secondary levers

66 and 67 being disposed in spaced aligned relation and in parallel relation to and intermediate the main lever 38 and the diaphragms 20-23 to form a very compact receivercontroller to be operated in a manner hereinafter described, the

diaphragm members

84 and 87 straddling the

secondary levers

66 and 67 to act directly on the main lever 38 while the

diaphragm members

85 and 86 are adapted to respectively act on the

secondary levers

66 and 67.

As illustrated in FIG. 5, the control device 10 is adapted to be interconnected to a fluid source conduit 100 that is indicated as MAIN in FIG. and the cham ber 34 is adapted to be interconnected to a controlled device (not shown) by a conduit means 101 that is labeled Branch in FIG. 5.

The chamber 36 is adapted to be interconnected by a conduit 102 to a signal generating device (not shown) by a conduit 102 that is labeled Signal No. 1 in FIG. 5. Similarly, the chamber 33 is adapted to be interconnected to a signal generating device by a conduit 103 that is labeled Signal No. 2 in FIG. 5 and the chamber 35 is adapted to be interconnected by a conduit 104 to a third signal generating device (not shown) labeled Signal No. 3 in FIG. 5.

The

conduits

100, 101, 102, 103 and 104 illustrated schematically in FIG. 5 are adapted to be interconnected to nipple means of the housing means 11 that are generally indicated by the reference numeral 105 in FIG. ll with the nipples 105 respectively leading by certain internal passages 37 of the housing means 11 to the appropriate chamber or device as indicated in FIG. 5.

For example, nipple means 105 can comprise

nipples

106, 107, 108, 109 and 110 respectively for interconnecting the branch conduit 101, the main conduit 100, the third signal conduit 104, the second signal conduit 103 and the first signal conduit 102 tothe control device 10.

It is well known that various pneumatically operated relay constructions can be provided internally in a housing means formed from a plurality of plates and the housing means 11 of the control device of this invention is provided with a multiplying relay therein that is generally indicated by the reference numeral 111 in FIG. 2 and is schematically illustrated as a rectangle in FIG. 5.

For example, the relay means 111 of the control device 10 can be of the form illustrated and described in the US. Pat. No. 3,575,190. Thus, this patent is incorporated in this disclosure by reference so that further details of the operation and structure of the relay construction 111 in order to understand the operation of the control device 10 need not be further described.

As illustrated in FIG. 5, the main conduit is interconnected to the relay 111 and the relay 111 is interconnected by a pilot passage means 112 to the leak port 65 while the main conduit 100 is also interconnected to leak port 65 by a passage means 113 having a restriction means 114 therein. The relay 111 is also interconnected by a passage means 115 to the conduit 101 that leads from the chamber 34 to the controlled device.

The operation of the control device 10 of this invention as schematically illustrated in FIG. 5 will now be described.

Assuming that the control device 10 is to be utilized as a single input model whereby fluid pressure is not to be directed to the

chambers

33 and 35 by the signal means No. 2 and No. 3, the signal generating device Signal No. 1 directs fluid pressure through the conduit 102 to the chamber 36 of the control device 10 which pressure force is applied through the flexible diaphragm 23 and diaphragm member 87 to the main beam or lever 38 to the right of the pivot point 41 to tend to move the lever 38 in a counterclockwise direction about the pivot point 41. However, if the main lever 38 is balanced, such force in the chamber 36 of the control device 10 is exactly opposed by the set point force of the compression spring 43 acting on the left-hand end of the lever 38 tending to move the lever 38 in a clockwise direction about the pivot point 41 as well as by force of the fluid pressure that is being delivered by the relay 11,1.into the branch chamber 34 and is acting on the diaphragm 21 tending to pivot the secondary lever 66 in a counterclockwise direction about its pivot point 70 and acting upwardly against the abutment means 82 of the lever 38 as illustrated in FIG. 5. In this manner, the relay 111 maintains the fluid pressure being directed into the conduit 101 and, thus, to the controlled device (not shown) at a certain value because of the balance beam 38 maintaining the valve member 64 at a certain position relative to the bleed port 65 as is well known in the art.

However, an increase in the force of the signal being directed into the chamber 36 of the control device 10 by the signal generating means No. 1 will cause a closing of the leak port 65 because such force in the chamber 36 acts upwardly on the diaphragm 23 and through the diaphragm member 87 causes the lever 38 to pivot in a counterclockwise direction on the pivot point 41 so that the chamber 61 moves upwardly in FIG. 5 to permit the valve member 64 to close closer to the bleed valve 65 and, thus, decrease the amount of bleed therethrough. This decrease in the bleed at the port 65 causes the relay ll 1, in a manner well known in the art, to increase the force of fluid being directed into the branch chamber 34 and, thus, to the controlled device interconnected to the conduit 101 until an equilibrium is again achieved to balance the beam or lever 38.

Conversely, a decrease of the pressure in the chamber 36 by the signal generating device No. 1 sensing another condition or the like, will cause the lever 38 to tend to move in a clockwise direction about the pivot point 41 and, thus, increase the amount of bleed through the bleed valve 65. However, the relay 1 11 will now cause a decrease in the pressure being directed to the branch chamber 34 and, thus, being directed by the conduit 101 to the controlled device to that the beam 38 will return to a balanced condition thereof.

Accordingly, for any setting of the control knob 56 of the control device 10, the control device is adapted to direct a branch signal out of the conduit 101 to the control device at a certain value when the signal to the signal chamber 36 is at a certain value and should that signal 36 change, the branch signal will correspondingly change at a particular rate corresponding to the setting of the control knob 56.

Changing the force of the set point spring 43 by the control knob 56 changes the pressure required from the signal generating device signal 1 to bring the instrument into balance and thereby changes the set point of the control device 10. Moving the abutment means 82 of the main lever 38 back and forth in the slot 81 changes the effective force applied by the secondary lever 66 to the main lever 38 by the branch diaphragm 21 and thereby changes the throttling range of the control device.

when it is desired to utilize the control device 10 with multiple inputs, such as using Signal No. 1, Signal No. 2 and Signal No. 3, it can be seen that the signal of the generating device No. 3 acts on the diaphragm 22 to the right of the fulcrum 41 and, thus, acts as an addition to the force of the signal in the chamber 36 and its authority on the system is adjustable over a wide range because of the adjustable abutment means 83 acting on the lever 67. The signal generating device No. 2 acts in subtraction to the signal generating device No. l and is fixed in its effect on the system as the same acts to the left of the fulcrum 41 and directlyon the lever 38.

Therefore, it can be seen that the control device 10 can be pneumatically operated and by having the main lever 38 and

secondary levers

66 and 67, as well as the diaphragms 20-23, disposed in the aligned space parallel relation previously described, a relatively compact.

unit can be provided which permits multiple diaphragms to act on a main lever of the control device 10 as well as on secondary levers thereof.

Thus, it can be seen that this invention not only provides an improved pneumatically operated control device, but also this invention provides improved parts for such a control device or the like.

While the form of the invention now preferred has been illustrated and described as required by the Patent Statute, it is to be understood that other forms can be utilized and still come within the scope of the appended claims.

What is claimed is:

1. In a control device having a movable lever and a control means controlled by the movement of said lever, the improvement comprising a flexible diaphragm carried by said control device and being movable relative thereto, said diaphragm having a continuous con-' upon movement of said diaphragm, and another movable lever carried by said control device and disposed intermediate said diaphragm and the first-mentioned lever, said diaphragm button having U-shaped means straddled by said other lever so as to be out of contact therewith while engaging said firstmentioned lever to move the same independently of said other lever.

2. In a control device as set forth in claim 1, the further improvement wherein said diaphragm has a locking rib extending therefrom into said tubular space, said diaphragm button having a recess therein receiving said rib therein to orient said diaphragm button relative to said diaphragm when said diaphragm button is disposed in said tubular space.

3. In a control device as set forth in claim 1, the further improvement wherein said convolution is annular and said diaphragm button has a generally cylindrical portion disposed against the inside surface of said convolution.

4. In a control device as set forth in claim 3, the further improvement wherein said control device has a plate provided with a generally cylindrical opening passing therethrough and receiving said convolution therein whereby said plate engages against the outside surface of said convolution to support the same.

, 5. In a control device as set forth in claim 1, the further improvement wherein said diaphragm button has abutment means engaging said first-mentioned lever and providing three point contact therewith.

6. In a control device as set forth in claim 1, the further improvement wherein said levers are disposed in spaced parallel relation.

7. In a control device as set forth in claim 6, the further improvement wherein another flexible diaphragm is carried by control device and is movable relative thereto, said other diaphragm having a diaphragm button engageable with said other lever to tend to cause movement thereof upon movement of said other diaphragm.

8. In a control device as set forth in claim 7, the further improvement wherein said first-mentioned lever carries on abutment means that engages against said other lever whereby the effective force of movement of said other lever is translated to said first-mentioned lever through said abutment means thereof to tend to move said first-mentioned lever.

9. In a control device as set forth in claim 8, the further improvement wherein said abutment means of said first-mentioned lever has means that is adjustable relative to said first-mentioned lever to adjust the effective force of said other lever acting on said first-mentioned lever.

10. In a control device as set forth in claim 9, the further improvement wherein a movable third lever is carried by said control device and acts on said firstmentioned lever in a similar manner to said other lever, said third lever being parallel to said first-mentioned lever and in aligned relation with said other lever.

11. A control device having a first movable lever and a control'means controlled by the movement of said first lever, a flexibleidiaphragm carried by said control device and having U-shaped means engaging said first lever to tend to cause movement of said lever upon movement of said diaphragm, and a second movable lever carried by said control device and disposed intermediate said diaphragm and said first lever to act on said first lever, said U-shaped means of said diaphragm being straddled by said second lever so that movement of said diaphragm will not cause movement of said second lever.

12. A control device as set forth in claim 11 wherein said levers are disposed in spaced parallel relation.

13. A control device as set forth in claim 12 wherein a third movable lever is carried by said control device to act on said first lever, said third lever being in spaced parallel relation to said first lever and being disposed in aligned relation with said second lever.

14. A control device as set forth in claim 11 wherein said first lever carries an abutment means that engages said second lever whereby the effective force of movement of said second lever is translated to said first lever phragm.

Claims

1. In a control device having a movable lever and a control means controlled by the movement of said lever, the improvement comprising a flexible diaphragm carried by said control device and being movable relative thereto, said diaphragm having a continuous convolution defining a tubular space therewithin, a diaphragm button disposed in said tubular space to be guided by said convolution and being in engagement with said lever to tend to cause movement of said lever upon movement of said diaphragm, and another movable lever carried by said control device and disposed intermediate said diaphragm and the first-mentioned lever, said diaphragm button having U-shaped means straddled by said other lever so as to be out of contact therewith while engaging said firstmentioned lever to move the same independently of said other lever.

5. In a control device as set forth in claim 1, the further improvement wherein said diaphragm button has abutment means engaging said first-mentioned lever and providing three point contact therewith.

10. In a control device as set forth in claim 9, the further improvement wherein a movable third lever is carried by said control device and acts on said first-mentioned lever in a similar manner to said other lever, said third lever being parallel to said first-mentioned lever and in aligned relation with said other lever.

11. A control device having a first movable lever and a control means controlled by the movement of said first lever, a flexible diaphragm carried by said control device and having U-shaped means engaging said first lever to tend to cause movement of said lever upon movement of said diaphragm, and a second movable lever carried by said control device and disposed intermediate said diaphragm and said first lever to act on said first lever, said U-shaped means of said diaphragm being straddled by said second lever so that movement of said diaphragm will not cause movement of said second lever.

14. A control device as set forth in claim 11 wherein said first lever carries an abutment means that engages said second lever whereby the effective force of movement of said second lever is translated to said first lever through said abutment means thereof to tend to move said first lever.

15. A control device as set forth in claim 14 wherein said abutment means of said first lever has means that is adjustable relative to said first lever to adjust the effective force of said second lever acting on said first lever.

16. A control device as set forth in claim 11 wherein said control device has another flexible diaphragm having means engageable with said second lever to tend to move the same upon movement of said second diaphragm.