US3643515A

US3643515A - Multioption control head

Info

Publication number: US3643515A
Application number: US4336A
Authority: US
Inventors: Arne H Hansen; Lester Victor Hebenstreit
Original assignee: Walter Kidde and Co Inc
Current assignee: BLOOM-1 Inc A CORP OF; Kidde Inc; Walter Kidde Fire Suppression Inc
Priority date: 1970-01-20
Filing date: 1970-01-20
Publication date: 1972-02-22
Anticipated expiration: 1989-02-22

Abstract

A valve-operating control head for a fire extinguishing system which can be equipped to be operated by either an electrical, a pneumatic, or a mechanical fire detecting system. The control head mechanism includes a lever centrally mounted on a pivot and carrying a trigger member rotatably mounted on one end thereof. The trigger holds a rotatable spring-loaded valve-operating device against operation by engaging a pin extending from the valve-operating device. A spring extending from the control head casing holds the trigger in engagement with a ratchet wheel carried by the pivot and also tends to rotate the lever and the trigger about the pivot to move the trigger out of engagement with the pin. The trigger is held against rotation about the pivot by either holding the free end of the lever or by holding the ratchet wheel from rotating. When the control head is utilized with an electrical detecting system, a solenoid is positioned to hold the lever and when it is used with a pneumatic system a diaphragm-operated arm holds the lever. When the control head is used with a mechanical detecting system a tensioned cable extending from a fusible link is wound around the ratchet wheel to hold it from rotating.

Description

United States Patent Hansen et al.

[54] MULTIOPTION CONTROL HEAD [72] inventors: Arne H. Hansen, New City, N.Y.; Lester Victor Hebenstreit, Bloomfield, NJ.

[73] Assignee: Walter Kidde & Company, Inc., Belleville,

221 Filed: Jan. 20, 1970 [211 Appl.No.: 4,336

[52] US. Cl... ..74/2 [51] int. Cl. ..G05g 17/00 [58] Field oiSearch ..74/2, 3.52; 169/7, 42, 21, 169/19; 251/66, 68, 74

[56] References Cited UNITED STATES PATENTS 268,523 12/1882 Nesbitt ..74/2 441,260 11/1890 Tyberg ..74/2 2,588,239 3/1952 Hopton.... .....74/2 2,872,820 2/1959 Cupedo .....74/2 2,991,658 7/ l 961 Haessler ..74/2 3,174,324 3/1965 Ostertag ..74/2 3,262,323 7/1966 Fallis ..74/2

3,419,083 12/1968 Cholin ..169/42X Feb. 22, 1972 FOREIGN PATENTS OR APPLICATIONS 103,416 1899 Germany ..74/2

Primary Examiner-Milton Kaufman Attorney-Darby & Darby [5 7] ABSTRACT A valve-operating control head for a fire extinguishing system which can be equipped to be operated by either an electrical, a pneumatic, or a mechanical fire detecting system. The control head mechanism includes a lever centrally mounted on a pivot and carrying a trigger member rotatably mounted on one end thereof. The trigger holds a rotatable spring-loaded valveoperating device against operation by engaging a pin extending from the valve-operating device. A spring extending from the control head casing holds the trigger in engagement with a ratchet wheel carried by the pivot and also tends to rotate the lever and the trigger about the pivot to move the trigger out of engagement with the pin. The trigger is held against rotation about the pivot by either holding the free end of the lever or by holding the ratchet wheel from rotating. When the control head is utilized with an electrical detecting system, a solenoid is positioned to hold the lever and when it is used with a pneumatic system a diaphragm-operated arm holds the lever. When the control head is used with a mechanical detecting system a tensioned cable extending from a fusible link is wound around the ratchet wheel to hold it from rotating.

18 Claims, 10 Drawing Figures PAIENIEBFEB22 I972 3, 64-3 1 5 sum 1 OF A INVENEfiRS ARNE rm ANS LESTER v. HE BENSTREW PAENIEBFEB 22 I972 SHEET '4 OF C) INIVENTORS ARNE mussn gxsm: v. Minimum a'liiii The present invention relates to control heads for actuating valves in fire extinguishing systems, and, more particularly, to such control heads which are operated by fire detecting systems.

A fire extinguishing system of this type must be provided with a control head designed to operate in response to the output of the particular fire detecting system installed in the area to be protected.

There are three basic types of fire detecting systems, electrical, pneumatic, and mechanical, and each type produces a different kind of output. ln'electrical systems, the presence of a fire alters the electrical characteristics of a detecting unit and produces an electricalsignal which is used to operate a device such as a solenoid. In pneumatic systems, the heat of a fire causes air expansion, for example in a tube, and the resulting pressure increase is used to move a diaphragm or piston. In mechanical systems, a fusible element, such as a link, is connected to a tensioned cable between an anchor point and a stored energy device which is allowed to operate when the link melts.

In the past it has been the practice to design a control head to be operated by a particular type of fire detecting system. Manufactures of fire extinguishing systems therefore have manufactured and stocked three different types of control heads, one for use with each of the three types offire detecting systems.

Accordingly, it is an object of the present invention to provide an improved control head for fire extinguishing systems which is operable by different types of fire detecting systems.

Another object is to provide a single control head which is operable by electrical, pneumatic and mechanical detecting systems and is also manually operable.

Another object is to provide such a control head which is operable by another control head and which is capable of operating another control head.

In accordance with the present invention the foregoing objects are accomplished by providing a control head for dispensing fluid medium under pressure comprising in combination a lever member having first and second ends mounted on a first pivot between the ends, a trigger member mounted on the first end of the lever member by means of a second pivot and extending toward the first pivot, means on the first pivot for engaging the trigger member, spring means connected to the trigger member for urging the trigger member to rotate about the second pivot against the engaging means and for urging the lever member to rotate in the opposite direction about the first pivot, actuating means for releasably holding the members against rotation about the first pivot, spring-loaded valve-operating means, and means on the trigger member for holding the valve-operating means against operation when the members are held against rotation.

BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of the invention has been chosen for purposes of illustration and description, and is shown in the accompanying drawings, forming a part of the specification, wherein:

FIG. 1 is an elevational view ofa control head according to the present invention which is arranged to be operated by a mechanical fire detecting system.

FIG. 2 is an elevation view ofa portion of the apparatus of FIG. 1 showing more clearly the basic elements of the control head.

FIG. 3 is a top view of the basic elements of the control head.

FIG. 4 is a sectional view taken along line 4-4 on FIG. 1 illustrating the valve-operating mechanism.

FIG. 5 is a sectional view taken along line 5-5 on FIG. 1.

FIG. 6 is a fragmentary elevational view of the apparatus of FIG. 1 arranged to be operated by an electrical fire detecting system.

FIG. 7 is a fragmentary elevational view of the apparatus of FIG. 1 arranged to be operated by a pneumatic fire detecting system.

FIG. 8 is a fragmentary view illustrating a detail of the mechanism shown in FIG. 7.

FIG. 9 is a sectional view taken along the line 9-9 on FIG. 8.

FIG. 10 is a fragmentary elevational view ofa control head arranged to be operated by the operation of another control head.

DETAILED DESCRIPTION Referring to the drawings in detail, there is shown a control head according to the present invention which is mounted on a valve body B that is fitted to a cylinder C containing fire extinguishing agent under pressure. The control head includes a generally rectangular casing 10,. a lever 11 pivotally mounted to the casing, a trigger member 12 pivotally mounted on the lever 10, a ratchet assembly 14 engaging the trigger member 12, and a valve-operating mechanism 15.

The casing 10 has

sidewalls

16 and 17, a top wall 19, a bottom wall 20, and a rear wall 21. A removable cover plate (not shown) is normally attached to the casing by means of screws which pass through holes in the cover plate and are screwed into the threaded holes 22 provided in the corners of the casmg.

Referring now to FIGS. 2 and 3, the ratchet assembly 14 is mounted on a shaft 24 which is journaled in a formation 25 within the casing. The lever 11 is pivotally mounted on the shaft 24 by means of an opening 26 near the center thereof through which the shaft 24 passes. The trigger member 12 is pivotally mounted on the left end (as viewed in FIGS. 1-3) of the lever by means of a bolt and nut assembly 27 which passes through openings in the lever and trigger member. A ratchet arm 29 having teeth 30 is mounted on a spacer member 31 (FIG. 3) which is secured to the trigger member 12.

Referring to FIGS. 1 to 3 the ratchet assembly 14 includes in addition to the shaft 24, a ratchet wheel 32, a cup-shaped drum 34, and a spacer sleeve 35 (FIG. 3). The shaft 24 extends through the drum 34, the wheel 32 and the sleeve 35, and is provided with a hexagonal head 36 within the drum to which the drum is welded. The wheel 32 is welded to the inner surface of the drum and the sleeve 35 is positioned between the wheel 32 and the formation 25. The ratchet wheel is formed with a series of teeth 37 which extend completely around its outer edge and intermesh with the teeth 30 on the ratchet arm 29.

A coil spring 38 extending between a hole 39 in the trigger member and an anchor pin 40 secured to the lower casing wall 20 holds the teeth of the ratchet arm in engagement with the teeth of the ratchet wheel. This spring also urges the trigger member 12 and the lever 11 to rotate counterclockwise about the shaft 24 to release the valve-operating mechanism 15.

Referring to FIG. 4, the valve operating mechanism 15 includes formation 41 extending upwardly from the bottom wall 20 of the casing and intersecting the formation 25, a stepped bore extending vertically through the formation 41 including a large diameter lower portion 42 and a smaller diameter upper portion 44, a plunger 45 having a large diameter head 46 positioned in the bore portion 42 and a small diameter shaft 47 extending through the upper bore portion 44, a spring 49 in the lower bore portion 42 urging the plunger 45 downwardly, a bore 50 in the formation 25 intersecting the bore portion 44, a cylindrical actuating member 51 in the bore 50 journaled on a bearing 52, a pin 54 mounted eccentrically in the inner end of the member 51 and extending into a horizontally oriented slot 55in the shaft 47 of the plunger, a bearing 56 surrounding the portion of the pin 54 within the slot 55, and a pair of pins 57 and 59 (FIGS. 1-3) extending radially outwardly from the cylindrical actuating member 51. The pin 57 engages a surface 60 on the right end ofthe trigger member 12.

The operation of the basic elements of the control head can best be understood by reference to FIGS. 2 to 4. The valve on the fire extinguishing cylinderis designed to be opened when the plunger 45 is allowed to move downwardly under the influence of the spring 49.

The plunger is maintained in the position shown by the engagement of the pin 57 with the surface 60 of the trigger member 12 which prevents rotation of the member 51. The spring 38 urges the rotation of the trigger member (together with the lever 11) around the shaft 24 in a counterclockwise direction so as to move the surface 60 out of engagement with the pin 57. The trigger member is held in the position shown either by holding the right-hand end of the lever 11 against counterclockwise movement by a solenoid or a pneumatically actuated lever as described hereinafter or by holding the ratchet wheel against such movement by a tensioned cable as described hereinafter. The tensioned cable, solenoid, or pneumatically actuated lever holding the lever and trigger member from counter clockwise movement is under the control of a fire detecting system. When the fire detecting system senses the presence of a fire, the lever and trigger member are released, as described hereinafter, and the lever 11, the trigger member 12, and the ratchet assembly 14 rotate under the influence of the spring 38. When the surface 60 moves out ofengagement with the pin 57, the plunger 45 is free to move downwardly under the action of the spring 49 and the cylindrical member 51 rotates counter clockwise.

The trigger member 12 is provided with an arm 61 which as shown in FIG. 3 is formed to be in alignment with the pin 59 extending from the member 51. Should the member 51 or the eccentric pin 54 bind and prevent the plunger 45 from moving, the arm 61 will strike the pin 59 as the trigger member 12 rotates about the axis of the shaft 24 and drive the cylindrical member 51 into rotation to allow the plunger to move.

Referring again to FIG. 1, the tap wall 19 of the casing is provided with an opening 62, the side wall 16 is provided with an opening 64 and the sidewall 17 is provided with an opening 65. As shown in FIG. 1, when the control head is connected to be operated by a mechanical fire detecting system, a cable 66 extends downwardly through the opening 62 and is wrapped around the drum 34. The cable 66 runs from the control head over pulleys (not shown) to the area under protection where it is connected to a fusible link or a series of such links. The other end of the link or series oflinks is anchored, for example by a cable attached to an eyebolt secured to a wall.

Before attaching the cable to the drum, the cover is removed from the casing, the trigger member is manually placed in the position shown in FIG. 1, and a pin 67 (FIG. 5) is passed through an arcuate slot 69 provided in the trigger member and is inserted in a bore 70 provided in the casing. As shown in FIG. 5, the bore 70 extends into a formation 71 and the pin 67 is provided with a reduced diameter section 72 in horizontal alignment with the trigger member 12. When the trigger member 12 is released it is rotated by the spring 38 counterclockwise until the edge of the slot 69 butts against the section 72 of the pin 67 preventing the pin 67 from being withdrawn.

The cable 66 is attached to the drum 34 by passing it through a hole 74 in the cylindrical wall of the drum and clamping a bead onto the end of the cable which is of larger diameter than the hole 74. The cable is then tensioned by rotating the ratchet assembly counterclockwise by means of a wrench applied to the hexagonal head 36 of the shaft 24 or by applying a screwdriver to a slot 75 provided in the head 36. When the tension in the cable 66 increases to the point that it begins to counterbalance the action of the spring 38, the trigger member 12 is moved clockwise each time the tension in the cable 66 is increased. The tension in the cable is in creased until the slot 69 is aligned with the bore 70 so that the pin 67 can be withdrawn. The pin 67 is of sufficient length so that the cover cannot be replaced until the pin is removed thus preventing the pin from being inadvertently left in the bore 70 to prevent the control head from functioning.

The trigger member 12 is held by the tension in the cable 66 in the position shown in FIG. 1. When a fire occurs in the protected area, the fusible links (or one of them) melts releasing the cable 66 and allowing the trigger member 12 to be rotated by the spring 38 to actuate the valve-operating mechanism.

When the control head is arranged to be operated by an electrical fire detecting system, the right-hand end of the lever 11 is held against the action ofthe spring 38 by a solenoid. The right end of the lever 11 is provided with an upwardly facing arcuate depression 76 and, as shown in FIG. 6, the solenoid 77 is mounted to the wall 17 of the casing and is provided with a plunger 79 which is normally seated in the depression 76 of the lever 11. When the electrical fire detecting system responds to the presence of a fire, it produces a signal which actuates the solenoid causing the plunger 79 to retract and free the lever 11 allowing the trigger member to rotate as previously described.

To arrange the control head to be operated by a pneumatic fire detecting system, a pressure sensor 80 is mounted on the top wall 19 of the casing as shown in FIG. 7. The sensor 80 includes an upwardly facing dish shaped lower body member 81 and a downwardly facing generally dish-shaped upper body member 82 providing a chamber therebetween, and an annular diaphragm 84 clamped between the members 81 and 82 to divide the chamber into an upper portion 85 and a lower portion 86. The upper body member 82 at one point along its outer edge has an enlargement 87 provided with a threaded bore 89 for the connection of a pneumatic line and an inlet passageway 90 connecting with the upper chamber portion 85. The member 82 is also formed with an upwardly extending peripheral flange 91 and a central upwardly extending cylindrical formation 92 provided with a threaded bore 94 and a vent hole 95 at the bottom of the bore 94. A screw 96 having a stepped central bore is threaded into the bore 94. The stepped bore includes an upper large diameter portion 97 containing a plug 99 of porous material and a lower smaller diameter portion 100 which places the plug 99 in fluid flow communication with the vent hole 95. The plug 99 allows air to escape very slowly from the chamber portion 85 so as to prevent normal ambient temperature changes (which take place slowly) from producing a pressure within the chamber portion sufficient to operate the control head.

The lower body member 81 is provided with a central opening 101 in alignment with the opening 62 in the casing wall 19. A lever 102 is pivotally mounted within the casing on a formation 104 and has an arm 105 extending horizontally from the pivot point to the opening 62 and an arm I06 extending downwardly at an angle from the pivot point to the right end of the lever 11. The arm 105 is provided with a vertical finger 107 which extends upwardly through the openings 62 and 101 to contact the diaphragm 84. The diaphragm 84 is provided with upper and lower reinforcing discs 109 and 110 on each side thereof, and the finger 107 contacts the lower disc 110.

As best shown in FIGS. 8 and 9, the end of arm 106 is provided with an extension 111 which extends at right angles to the arm and is bent back upon itself to provide the U"- shaped formation shown in FIG. 9. A bar 112 is pivoted within the U-shaped formation on a pin 114 and a stop pin 115 extends from the arm 106 to prevent counterclockwise rotation (as shown in FIG. 8) of the bar 112. The bar 112 has a pointed lower end 116 which engages a notch 117 formed in the end of the lever 11 I.

The casing 10 is provided with an internally threaded tubular formation 119 extending outwardly from the upper end of the wall 17. A coil spring 120 positioned within the formation 119 is connected between a screw assembly 121 threaded into the formation and a link member 122 attached to the arm 105. The spring 120 tends to rotate the lever 102 in a clockwise direction to hold the pointed end 116 of the bar 112 firmly in the notch 117 in the lever 11. When the lever 102 is being biased in this direction, the bar 112 is pressed firmly against the pin 115 so as to act as an extension of the arm 106. The screw assembly 121 includes a cup-shaped screw 124 having a bore 125 in the inner wall thereof and a connecting pin 126 extending through the bore 125 and having an enlarged head 127 within the screw 124. The force exerted by the spring 120 is adjusted by turning the screw 124, by means of screwdriver slots 129, to control the diaphragm pressure required to operate the control head.

When a fire occurs in the area under protection, the air within the pneumatic tubing connected to the pressure sensor 80 is heated and expands increasing the pressure within the upper chamber portion 85. The pressure within the chamber portion 85 pushes the diaphragm 84 down against the finger 107 of the lever 102. When the diaphragm pressure overcomes the action of the spring the lever 102 begins to move counterclockwise. Referring to FIG. 8, the rotation of the lever 102 moves to the pivot pin 114 to the right allowing the bar 112 to pivot about its point and rotate clockwise to release the lever 11 permitting the trigger member 12 to rotate actuating the control head.

Referring once again to FIG. 1, the control head is provided with a lever 130 which can be used to manually operate the control head. The lever 130 is carried by a shaft 131 pivotally mounted in the rear wall 21 of the casing and includes a vertically extending arm 132 and a horizontally extending arm 134-. The vertically extending arm 132 is provided with a curved cam surface 135 protruding from its left edge and engaging a forwardly extending flange 136 on the trigger member 12. On the lower end of the arm 132, a tab 137 is provided which extends forwardly and is provided with a hole (not shown) for purposes described hereinafter. The horizontal arm 134 is vertically aligned with the pin 57 of the valve-operating mechanism 15. The rotatable shaft 131 is provided with a slot 139 for receiving a handle (not shown). The cover plate previously discussed has an opening therein aligned with the shaft 131 to permit use of the handle when the cover plate is in place.

When the handle is used to rotate the lever 130 clockwise, the engagement of the cam surface 135 and flange 136 forces the trigger member 12 to rotate counterclockwise. When the control head is arranged for operation by a mechanical fire detecting system as shown in FIG. 1, the lever 130 merely has to move the trigger member 12 far enough to disengage the teeth 30 of the ratchet arm 29 from the teeth 32 of the ratchet wheel. The trigger member and the lever 11 are then free to rotate about the shaft 24. When the control head is arranged for operation by an electrical or pneumatic system wherein the lever 11 is locked against movement, the lever 130 must rotate the trigger member about the bolt and nut assembly 25 until the surface 60 clears the pin 57. Should any elements within the valve-operating mechanism bind so as to prevent its operation, continued movement of the lever 130 will cause the right end of the arm 134 to strike the pin 57 and free the mechanism.

As shown in FIGS. 1 and 10, when a second fire extinguishing cylinder is included in the system, the second cylinder is provided with a control head identical to the one described hereinabove. This second control head normally is not connected to the fire detecting system but rather is connected to be operated by the operation of the first control head. The connection between the control heads is provided by a cable 140 which is fastened to the pin 59 and wrapped around the member 51 of the first control head (FIG. 1). The cable 140 passes through the opening 65 in the wall 17 of the first control head, enters the second control head (FIG. through the opening 64' and passes through the hole in the tab 137 of the lever 130. The cable is pulled taught and a clamp 141 is applied to the cable. In the second control head (FIG. 10) the trigger member 12' is kept from rotating only by the engagement of the lever 130 with the flange 136' of the trigger member. The flange 136 is pressed against the cam surface 135 by the action of the spring 38 producing a frictional force which holds the trigger member 12' in position against the action ofthe spring 38'.

When the first control head is operated, the member 51 rotates clockwise removing the tension from the cable 140. The lever 130 in the second control head is thus released allowing the trigger member to rotate under the influence 0f the spring 38'. The second control head may be employed to operate a third control head in the same manner.

It will be seen from the foregoing, that the present invention provides an improved control head for fire extinguishing systems which is operable by electrical, pneumatic and mechanical detecting systems, and in addition, is manually operable and is capable ofoperating another control head.

We claim:

1. A control head for use in dispensing fluid medium under pressure comprising in combination a lever member having first and second ends, a first pivot means on which said lever member is mounted between its ends, a trigger member mounted on said first end of said lever member by second pivot means, said trigger member having a first portion thereof extending toward said first pivot means, means on said first pivot means for engaging said first portion of said trigger member, spring means connected to said trigger member for urging said trigger member to rotate about said second pivot means and to bring said first portion of said trigger member into engagement against said engaging means on said first pivot means and for urging said lever member to rotate in the opposite direction about said first pivot means, actuating means for releasably holding said first portion of said trigger member in engagement with said engaging means on said first pivot means to prevent said lever member and said trigger member from rotating about said first pivot means, springloaded valve-operating means, means on said trigger member for holding said valve-operating means against operation when said first lever and said trigger members are held from rotating.

2. A control head according to claim 1 wherein said actuating means is positioned to releasably engage said second end of said lever member to hold said lever and trigger members against rotation.

3. A control head according to claim 2 wherein said actuat ing means includes a diaphragm operated by fluid pressure, a lever element having a first end contacting said diaphragm and having a second end engaging said second end of said lever member, and a spring attached to said lever element to act against said diaphragm to said second end of said lever element in contact with said lever member.

4. A control head according to claim 3 wherein said second end of said lever member is provided with a notch therein, and said second end of said lever element has a bar pivoted thereto and is provided with a stop element to hold the bar against rotation in one direction, said stop element being positioned to prevent rotation of said bar when said bar is urged into said notch by the action of said spring upon said lever element, said diaphragm being responsive to a change in pressure in a predetermined direction to move said lever element against said spring and allow said bar to rotate in the other direction to release said lever member.

5. A control head as in claim 2 wherein said actuating means comprises an electrically operated means having a plunger portion which engages said second end of said lever member.

6. A control head according to claim 1 wherein said engaging means of said first pivot means includes a wheel member rotatable on said first pivot means, said wheel member and said trigger member having interengaging elements preventing relative rotation therebetween in one direction, said actuating means being connected to said wheel member to normally prevent said wheel member from rotating by the force transmitted from said spring means through said trigger member and said lever member.

7. A control head according to claim 6 wherein said actuating means includes cable means secured to said wheel member and wherein said interengaging elements permit rotation of said wheel member in a direction to tension said cable means to hold said trigger member against the action of said spring means.

8. A control head according to claim 7 wherein a drum member is secured to said wheel member and said cable means is attached to said drum member.

9. A control head according to claim 7 wherein said wheel member is rotated in a direction opposite said one direction by said spring upon relaxation of the tension in said cable.

10. A control head according to claim 7 further comprising a stop means for engagement with said trigger member and another portion of said control head to prevent said trigger member from rotating about said first pivot means, means on said wheel member for rotating the same to increase the tension in said cable means as said wheel member is rotated in said one direction, and means formed on said stop means to prevent disengagement from said trigger member until the cable has been tensioned to a predetermined degree.

11. A control head as in claim 10 wherein said stop means comprises a pin having a reduced diameter section, a slot formed in said trigger member through which said pin projects to engage said other portion of said control head, a portion of said trigger member surrounding said slot for engaging said pin at its reduced diameter portion, said trigger member being moved as said cable is being tensioned by rotation of said wheel to move said slot to a position where the pin can be withdrawn when said cable has been tensioned to said predetermined degree.

12. A control head according to claim 1 wherein said valveoperating holding means on said trigger member includes a projection extending past said first pivot means and wherein said spring-loaded valve-operating means includes a rotatable actuating member, a spring member for urging said rotatable actuating member to rotate, and an element on said rotatable actuating member for engaging said projection on said trigger member, said trigger member being rotatable about said first pivot under the influence of said spring member to move said projection out of engagement with said projection-engaging element.

13. A control head according to claim 12 wherein said projection-engaging element is a pin extending radially from said rotatable actuating member, said rotatable actuating member is provided with a second pin extending radially therefrom, and said trigger member is provided with a formation aligned with said second pin so as to strike said second pin when said said rotatable actuating member does not rotate when said projection moves out ofengagement with said first pin.

14. A control head according to claim 1 including a manually operable lever for engaging and rotating said trigger member about said second pivot to release said valve-operating means.

15. A control head according to claim 17 wherein said valve-operating means includes a rotatable actuating member, a spring member urging said actuating member to rotate, and a pin extending radially from said actuating member for engaging said trigger member, and wherein said manually operable lever includes a first arm for engaging said trigger and a second arm for engaging said pin in the event said actuating member does not rotate when said trigger member rotates about said second pivot.

16. A control head according to claim 14 wherein said actuating means includes said manual lever, tensioned cable means, and means for releasing said cable means, said trigger member and said manual lever being provided with interengaging surfaces, said manual lever having a position wherein said surfaces are engaged so that said manual lever is capable of holding said trigger member against the action of said spring means, said tensioned cable being connected to said manual lever to hold said lever in said position.

17. A control head according to claim 16 wherein said means for releasing said tension cable includes a valve-operating mechanism in another control head whereby said manual lever is released to allow said trigger to rotate in response to the operation of the valve-operating mechanism in said other control head.

18. A control head according to claim 1 wherein said valveoperating holding means on said trigger member includes a projection extending past said first pivot means and wherein said spring loaded valve-operating means includes a rotatable actuating member, a spring member for urging said rotatable actuating member to rotate, and an element on said rotatable actuating member for engaging said projection on said trigger member, a manually operable lever for engaging and rotating said trigger member about said second pivot to move said projection out of engagement with said projection-engaging element.

\1 trigger member rotates about said first pivot in the event that

Claims

1. A control head for use in dispensing fluid medium under pressure comprising in combination a lever member having first and second ends, a first pivot means on which said lever member is mounted between its ends, a trigger member mounted on said first end of said lever member by second pivot means, said trigger member having a first portion thereof extending toward said first pivot means, means on said first pivot means for engaging said first portion of said trigger member, spring means connected to said trigger member for urging said trigger member to rotate about said second pivot means and to bring said first portion of said trigger member into engagement against said engaging means on said first pivot means and for urging said lever member to rotate in the opposite direction about said first pivot means, actuating means for releasably holding said first portion of saId trigger member in engagement with said engaging means on said first pivot means to prevent said lever member and said trigger member from rotating about said first pivot means, spring-loaded valve-operating means, means on said trigger member for holding said valve-operating means against operation when said first lever and said trigger members are held from rotating.

3. A control head according to claim 2 wherein said actuating means includes a diaphragm operated by fluid pressure, a lever element having a first end contacting said diaphragm and having a second end engaging said second end of said lever member, and a spring attached to said lever element to act against said diaphragm to said second end of said lever element in contact with said lever member.

12. A conTrol head according to claim 1 wherein said valve-operating holding means on said trigger member includes a projection extending past said first pivot means and wherein said spring-loaded valve-operating means includes a rotatable actuating member, a spring member for urging said rotatable actuating member to rotate, and an element on said rotatable actuating member for engaging said projection on said trigger member, said trigger member being rotatable about said first pivot under the influence of said spring member to move said projection out of engagement with said projection-engaging element.

13. A control head according to claim 12 wherein said projection-engaging element is a pin extending radially from said rotatable actuating member, said rotatable actuating member is provided with a second pin extending radially therefrom, and said trigger member is provided with a formation aligned with said second pin so as to strike said second pin when said trigger member rotates about said first pivot in the event that said rotatable actuating member does not rotate when said projection moves out of engagement with said first pin.

18. A control head according to claim 1 wherein said valve-operating holding means on said trigger member includes a projection extending past said first pivot means and wherein said spring loaded valve-operating means includes a rotatable actuating member, a spring member for urging said rotatable actuating member to rotate, and an element on said rotatable actuating member for engaging said projection on said trigger member, a manually operable lever for engaging and rotating said trigger member about said second pivot to move said projection out of engagement with said projection-engaging element.