CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-pβrt of prior co-pending application Serial No. 412,831, filed: August 30, 1982 , which is a continuation-in-part of application Serial No. 179,168 , filed: August 18 , 1980, now U. S . Patent 4,349,980. BACKGROUND OF THE INVENTION

Field of the Invention

The present invention pertains to a pneumatically actuated rodent exterminating apparatus having a pneumatic actuator which moves a rodent striking bar between retracted and striking positions and includes a second actuator which is operable in timed relation to the actuation of the striking bar to effect removal of a rodent from the vicinity of the rodent detection mechanism. A sequencing control circuit includes improved high speed, no leakage control valves. Background The longstanding problem of exterminating rodents and other pests in commercial establishments , such as grain elevators, food storage warehouses and myriad other places where rodents frequent and attempt to establish habitats , cannot be effectively dealt with using prior art typέs of exterminating apparatus or chemical exterminating techniques. With the increased resistance to known types of chemical poisons there has been an acute need for a reliable automatic resetting power operated exterminating apparatus which is

capable of multiple kills between maintenance operations. In this regard also there has been a need for a mechanical rodent exterminating apparatus which is compact, capable of reliable repeat operating cycles to perform multiple kills and which utilizes a minimum amount of energy from a source such as a reservoir or other source of compressed air or similar pressure fluid.

One factor which is of particular importance in the development of a suitable pneumatically actuated rodent exterminating device is the provision of a control circuit with control valving which is capable of reliable and rapid valve shifting movement and which is adapted for minimal fluid leakage in any position of the valve closure member. Accordingly, the problems of providing a compact, powerful and reliable rodent exterminating apparatus of the impact or striking bar type and which is adapted for automatic resetting for the performance of repeat operating cycles have been overcome with the pneumatically actuated apparatus having a unique control circuit and associated fluid control valving in accordance with the present invention.

SUMMARY OF THE INVENTION The present invention provides a power operated rodent exterminating apparatus including a pressure fluid operated actuator for moving a rodent striking member between retracted and striking positions and including control means for automatically resetting the apparatus for the performance of repeat rodent kill cycles. In accordance with one aspect of the invention there is provided an improved arrangement of a pressure fluid cylinder and piston type actuator in combination with a pivotally mounted rodent striking bar which provides a compact apparatus and which also provides superior mechanical advantage for delivering a fatal blow to a rodent or other pest.

In accordance with another aspect of the present invention there is provided a rodent exterminating apparatus having an improved detection and triggering mechanism for detecting the presence of a rodent in a striking position and for actuating a high speed pneumatic control circuit for sequencing the operation of the striking bar actuator and for operating a rodent ejection mechanism to clear the detection and triggering mechanism whereby the apparatus

may be automatically reset for another operating cycle. The power actuated rodent ejection mechanism includes a pair of opposed pivotally mounted sweeper gates which are operated by a pneumatic actuator to remove an expired rodent from the vicinity of the detection mechanism whereby the exterminating apparatus may be automatically reset for a subsequent operating cycle.

In accordance with yet a further aspect of the present invention there is provided a rodent exterminating apparatus in combination with an improved automatic control circuit which detects the presence of a rodent, actuates the striking bar actuator to deliver a fatal blow to the rodent, resets the striking bar and actuates a rodent ejection mechanism to remove the rodent from the vicinity of the detection mechanism. The control circuit includes a plurality of pneumatic valves which are of unique construction and include lightweight , fast acting closure members, and pilot actuators of improved low cost construction. The control valves include molded plastic spool or poppet type closure members and modular molded plastic housing parts and are provided with a unique arrangement of flexible rolling diaphragm pilot actuators to provide for low friction, high speed actuation of the closure members and to provide for minimal fluid leakage through the valves.

The abovedescribed features and advantages of the present invention as well as additional superior aspects thereof will be further appreciated by those skilled in the art upon reading the detailed description which follows in conjunction with the drawing.

BRIEF DESCRIPTION OF THE DRAWING Figure 1 is a side elevation, partially sectioned, of the rodent exterminating apparatus of the present invention;

Figure 2 is a plan view, partially sectioned, of the rodent exterminating apparatus;

Figure 3 is a front elevation of the apparatus; Figure 4 is a detail section view taken along the line 4-4 of Figure 2 ;

Figure 5 is a control circuit diagram for the apparatus; Figure 6 is a section view of the valving for the striking bar actuator taken along the line 6-6 of Figure 1;

Figure 7 is a section view of the valving for the ejection mechanism actuator taken along the line 7-7 of Figure 1; and

Figure 8 is a view taken generally from line 8-8 of Figure 7. DESCRIPTION OF THE PREFERRED EMBODIMENT

In the description which follows like parts are marked throughout the specification and drawing with the same reference numerals, respectively. The drawing figures are not necessarily to scale and certain features may be shown in schematic form in the interest of clarity and conciseness.

Referring to Figures 1 and 2 , in particular, there is illustrated a rodent exterminating apparatus, generally designated by the numeral 10 , comprising a frame characterized by a generally planar rectangular base member 12. The frame 12 includes an upstanding pedestal portion 14 and a plurality of vertically extending spaced apart support posts 16 for supporting a pneumatic reciprocating plunger and cylinder type actuator, generally designated by the numeral 18. The actuator 18 includes a cylinder 20 forming an interior pressure fluid chamber 22 in which is disposed a reciprocating piston or plunger 24. The piston 24 is characterized by a body part 26 and a flexible diaphragm 28 extending across the chamber 22 and supported on the cylinder 20 by a cylinder extension member 30. The piston body 26 is connected to an elongated piston rod member 32 which extends through an enlarged opening 34 in an end cover 36. The actuator 18 also includes a pressure fluid inlet reservoir 38 defining a reservoir chamber 40. The chamber 40 may include a particulate matter filter member 42 disposed therein for filtering inlet air to the apparatus 10. Pressure air is communicated to the reservoir chamber 40 through a suitable inlet conduit 43 which may be coupled to a source of pressure air not shown through a quick release coupling 44.

The nominal longitudinal stroke axis of the piston 24 and the rod 32 typically extends vertically and is designated by the numeral 46. The piston rod 32 is provided with a distal end part 47 including a transverse crank pin 48 which extends in opposite directions from the end part 47 and is in engagement with opposed crank members 50 which are each supported on the base member 12

by laterally projecting trunnions 52 journalled in opposed bearing bosses 54. As indicated in Figure 2 , the axis 49 of the crank pin 48 is spaced from the axis 53 of the trunnions 52 to provide for rotating the cranks 50 about the axis of the trunnions in response to reciprocation of the piston rod 32.

The crank members 50 are each connected to an elongated formed wire or rod type striking bar, generally designated by the numeral 56. The striking bar 56 has a traverse base leg 58 , Figure 3 , and opposed parallel side legs 60 , the distal ends of which are each secured to a crank member 50. In response to movement of the piston 28 generally vertically downward, viewing Figure 1, the striking bar 56 is moved from the retracted, generally vertically extending position shown by the solid lines in Figure 1 to a striking position, indicated by the dashed lines in Figure 1 down over the pedestal portion 14 and in engagement with an anvil surface 13 on the frame 12. The striking bar 56 is moved to the striking position with great force under the urging of high pressure air introduced into the chamber 22 to act on the piston 28. The striking bar 56 is returned to the retracted position , substantially enclosing the actuator 18 , upon venting pressure air from the chamber 22 , by a coil spring 62 disposed in surrounding relationship to the piston rod 32 and between the cover member 36 and the piston body 26. Accordingly, in response to introduction of pressure fluid into the chamber 22 the striking bar 56 may be forcibly rotated to the striking position to deal a fatal blow to a rodent in the vicinity of the base leg 58 or portions of the side legs 60 extending from the base leg. Pressure air is introduced into the chamber 22 from the chamber 38 through a control valve module, generally designated by the numeral 64. The control valve module 64 includes a plurality of control valves interconnected to provide a control circuit for valving pressure air from the chamber 40 to the chamber 22 by way of passages 66 and 68 , Figure 2 , and for venting pressure air from the chamber 22 by way of the passage 68 to atmosphere through the valve module 64 as will be described in further detail herein. Actuation of the striking bar 56 is initiated, upon sensing the presence of a rodent in the vicinity of the apparatus 10 , by detection means comprising a movable rodent detection plate member

70. The detection plate 70 is a generally planar member which is supported on a shaft 72 , Figure 4, for pivotal movement about the longitudinal axis of the shaft. The shaft 72 is supported in opposed bearing grooves 74 formed in the pedestal part 14 and secured by removable screws 75. The pedestal part 14 includes a recess 15 providing clearance for the plate 70. Spaced apart slots 17 are formed in the frame 12 for securing the apparatus in selected positions to various structures, not shown. As shown in Figure 1, an actuator link 76 extends generally vertically upward from one end 71 of the detector plate 70 and is provided with a slot 78 for receiving an actuating pin 80 for a pilot pressure fluid release valve comprising a part of the valve module 64. The detector plate 70 is operable to pivot about the axis of the support shaft 72 to move the link 76 generally upward until the actuating pin 80 is engaged by the link to effect release of pilot fluid pressure in a pilot pressure fluid actuator for a control valve in the valve module 64 to cause pressure air to be valved to the chamber 22. The detector plate 70 is responsive to engagement along virtually any part of a surface 73 between the shaft 72 and the distal end 77 of the plate to effect the pivotal movement described above. The plate 70 is balanced to assume an at rest position as shown in Figure 1 as long as there is nothing resting on the plate or forcibly engaging it to rotate it in a generally clockwise manner, viewing Figure 1 , about the pivot axis of the shaft 72. Accordingly, in response to a rodent coming into contact with the surface 73 of the detector plate the actuating link 76 will engage the pressure relief valve pin 80 to cause actuation of the striking bar 56 to move from its retracted position to its striking position sweeping an arc which will result in forcible striking of a rodent and pinning it between the anvil surface 13 and the striking bar.

Once the rodent has been struck a fatal blow it is necessary to eject the rodent from the vicinity of the detector plate 70 and the striking bar 56 so that the apparatus 10 becomes operable to perform a repeat cycle of striking another rodent which may venture into contact with the detector plate. In this regard, the apparatus 10 is provided with unique rodent ejector means comprising a pair of opposed ejector gates 82 and 84, see Figures 1 through 3,

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which are mounted for pivotal movement on the base 12 to sweep over the surface 73 to clear the detector plate 70 of an expired rodent. The gates 82 and 84 are mounted for pivotal movement on the frame pedestal part 14 by vertically extending support pins 86 which extend through suitable bores formed in respective hubs 83 and 85 of the gates 82 and 84 and are anchored in the pedestal part 14. The gate 82 is provided with a plurality of spaced apart tines 87 which are operable to be interleaved with opposed tines 88 projecting from the hub of the gate 84. The tines 87 and 88 are of sufficient length to sweep substantially the entire surface 73 to clear the detector plate of any obstruction.

The gates 82 and 84 are formed with respective bifurcated crank arms 90 and 92 , Figures 2 and 3 , which are each connected by way of pivot pins 95 to piston rods 94 of an opposed piston pneumatic actuator 96. The actuator 96 is supported by and between the gates

82 and 84. The actuator 96 comprises a cylinder member 98 in which are disposed opposed reciprocable pistons 100 connected to the rods

94, respectively. In response to introduction of pressure fluid into a chamber 102 , formed in cylinder 98 between the pistons 100, the gates 82 and 84 may be pivoted from a closed or retracted position as indicated by the solid lines in Figures. 1, 2 and 3 , to an open position, as indicated by the dashed lines in Figures 1 and 2 , to sweep the surface 73 of the detector plate 70 clear of any portion of a rodent or other object which may be in contact with the plate. The cylinder member 98 is connected to valve module 64 by a flexible conduit 107.

The gates 82 and 84 are returned to their retracted positions by conical coil springs 105 disposed around the piston rods 94 and between each of the respective pistons 100 and opposed endwalls 99 of the cylinder 98. Accordingly, in response to valving pressure fluid into cylinder chamber 102 , formed between pistons 100 , the gates 82 and 84 are moved from their retracted positions to their open positions to sweep the detector plate clear of a rodent carcass and, upon venting the chamber 102 , the springs 105 return the pistons 100 to their adjacent positions to move the gates 82 and 84 into the closed interleaved positions of the respective tines 87 and 88. As shown in Figure 1 , a partition plate 109 extends generally

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horizontally above the detector plate 70 and may support a suitable attractant or bait, not shown, to cause a rodent to move into engagement with the detector plate 70 to effect operation of the apparatus 10. The apparatus 10 may be provided with a suitable boxlike cover 110 suitably releasably secured to the frame 12 and provided with a carrying handle 111. The cover 110 is cut away at 112 to form an opening for access to the detector plate 70 by a rodent attracted to the bait or other attractant, not shown. A second opening 114 is provided in the back wall 115 of the cover for connecting a source of pressure air, not shown, to the conduit 43 through the coupler 44.

Referring now to Figure 5 , there is illustrated a schematic diagram of the valving in the valve module 64 which is operable to effect an operating cycle of the apparatus 10. The valve module 64 includes a plurality of two position pilot pressure fluid actuated valves 116 , 118 , 120 and 122 which are suitably interconnected to effect operation of the actuators 18 and 96. The valves 116 , 118 , 120 and 122 are each operable to be in respective positions a or b. With pressure fluid supplied to the conduit or passage 66 , the valve 116 is biased into its position b by a pilot actuator 124 having a flow restrictor 126 for controlling the rate of shift of the valve from position a to position b_. The pilot actuator 124 is also operable to be vented through a pressure relief valve 128 connected to the relief valve actuating pin 80. When valve 116 is in its position b_ flow of pressure fluid to the actuator 18 is blocked and valve 118 is biased in its position a. Accordingly, in this position of the actuator 18 the striking bar 56 is retracted in its substantially upstanding position. Upon actuation of the pin 80 through the detector plate 70 and the link 76 pressure fluid is vented from the pilot actuator 124 to shift valve 116 to its position a to conduct pressure fluid through valve

118 to the actuator 18 to effect forcible movement of the striking bar at a high rate of speed to strike a rodent which has activated the apparatus through engagement with the detector plate 70. After a suitable time delay, effected by a flow restrictor 130 , the valve 118 is operable to shift to position b upon pressurization of its pilot actuator

131. In position b_ the valve 118 vents pressure fluid from the

actuator 18 to atmosphere to allow the striking bar 56 to return to .its retracted position under the urging of the spring 62.

When the valve 116 supplies pressure fluid to the valve 118 pressure fluid is also supplied to the valve 120 which is normally in its position a but, upon conducting pressure fluid to the valve 120 , and after a suitable time delay effected by a flow restrictor 137 , a pilot actuator 133 is operable to shift the valve 120 to its position b to conduct pressure fluid to actuator 96 to effect opening of the gates 82 and 84 to clear the surface 73 of the detector plate 70. The flow restrictors 130 and 137 are calibrated such that the valve 118 will shift to its position b to vent actuator 18 to allow the striking bar 56 to return to its retracted position before valve 120 shifts to its position b to effect actuation of the gates 82 and 84. When pressure fluid is supplied by valve 120 to the actuator 96 , after a suitable time delay effected by a flow restrictor 139 , valve 122 is shifted from its position a to its position b by a pilot actuator 135 to vent the pilot actuator 133 thereby returning valve 120 to its position a. Once the detector plate 70 has been cleared the pin 80 allows valve 128 to close thereby pressurizing pilot actuator 124 and returning valve 116 to its position b blocking the flow of pressure fluid to any of the valves

118 , 120 or 122. Upon movement of the valve 120 to its position a the actuator 96 is vented to allow the gates 82 and 84 to return to the retracted position under the urging of the springs 105. Accordingly, the control circuit and the apparatus 10 are reset for another operating cycle. The valves 116 , 118 , 120 and 122 all include spring actuators 125 which bias the valves into their respective positions a as indicated by the schematic diagram of Figure 5.

Referring now to Figure 6 , there is illustrated a portion of the valve module 64 include the valves 116 and 118 which are of a unique configuration and share a modular body structure. The valves 116 and 118 include a common body part 150 which comprises a pair of spaced apart parallel bores 152 and 154 which are each delimited by opposed frusto-conical valve seats 156 , 158 and 160 , 162 , respectively. Reduced diameter bore portions 164 and 166 open into the bores 152 and 154. A pressure air supply port 168 opens into the bore 164 and is in direct communication with the passage 66. A port 170 opens into the bore 154 and is direct communication with the

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passage 68 leading to the cylinder chamber 22. The valves 116 and 118 also share a common body part 172 including a cylindrical boss 174 which closes one end of the bore 164 and a boss 175 fitted in bore 154 and forming seat 162. The body part 172 also includes a stepped bore 176 opening through boss 175 into the bore 154. An identical body part 172 is secured to the body part 150 at the opposite end thereof wherein the boss 174 closes one end of the bore 166 of the valve 118 and the bore 176 opens into the bore 152 of the valve 116. The body parts 172 each include a port 180 opening into the bore 176 , which, in the configuration of the valves 116 and 118 , comprises an exhaust port and which is fitted with a suitable pressure air exhaust and muffler plug 186 threadedly engaged with cooperating threads formed in the port 180.

The valves 116 and 118 each include an intermediate body part 188 having a stepped bore 189 , 191, the latter bore portion 191 being larger in diameter than the bore portion 189. The body part 188 provides support for the respective pilot pressure fluid actuators 124 and 131 of the respective valves. A cover member 190 is provided for the valve 116 and includes a cavity 192 which opens into a chamber 194 for the pressure relief valve 128 of the pilot actuator

124. The pressure relief valve 128 includes a valve closure member 196 which is biased by a coil ..spring 198 against a valve seat 200. The closure member 196 is formed integral with the actuating pin 80 which projects through a passage 202 formed in the valve seat 200. In response to deflection of the pin 80 the closure member 196 moves away from the seat 200 to allow pressure air to escape from the cavity 192 through passage 202 to effect shifting of the closure member for the valve 116 as previously described.

Referring further to Figure 6 , the valves 116 and 118 are each provided with a unique cylindrical plug or so-called spool type closure member, generally designated by the numeral 206 which includes a generally cylindrical plug 208 molded integral with a core member 210 , one shown. Each core member 210 includes an elongated cylindrical shaft portion 212 which projects axially into the bore 176 and is secured to the pilot actuator 124 and 131 , respectively. The closure members 206 include a second shaft portion 214 projecting into the bores 164 and 166 and engaged with the coil springs 125 which

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are operable to bias the closure members for the valve 116 and 118 toward the seats 158 and 162 , respectively.

The pilot actuator 124 is characterized by a pair of opposed flexible rolling diaphragm members 218 and 220 each having respective integral hub portions 219 and 221. The diaphragm members 218 and 220 are secured on a reduced diameter portion 213 of the shaft 212 and are partially supported by an intermediate support member 224. The diaphragm members 218 and 220 are both integrally formed of a suitable elastomeric material such as molded neoprene or polyurethane and are fitted over the shaft portion 213 in the manner illustrated.

The hub portion 219 is secured against a shoulder 215 between the shaft portions 212 and 213 in assembly with the support member 224 and the diaphragms are secured on the shaft portion 213 by wedging engagement of the respective hub portions 219 and 221 into opposed conical bores 225 and 227 formed in the support member 224. The diaphragms 218 and 220 are both preferably formed with axial bores in their respective hub portions 219 and 221 which are. slightly smaller than the diameter of the shaft portion 213 wherein,- on assembly the hub portions grip the shaft portion 213 and the wedging engagement of the hubs 219 and 221 into the conical bores 225 and

227 secures the pilot actuator 124 in assembled relationshi ' with the closure member 206. The diaphragms 218 and 220 of actuator 124 are suitably clamped about their respective peripheral edges between opposed faces of the body part 188 and the respective body parts 172 and 190. The effective axial projected face area of the diaphragm 220 is greater than that of the diaphragm 218 when assembled in the valve 116 , as illustrated, whereby the closure member 206 will be shifted into fluid-tight engagement with the seat 156 in response to the introduction of pressure fluid into the cavity 192. A chamber in body part 188 formed between diaphragms 218 and 220 is vented through a passage 223.

Pressure fluid is communicated to the cavity 192 through a groove 230 formed in the closure member shaft portion 214 , which groove is in communication with an axially extending passage 232 opening to the distal end of the shaft portion 213. A sintered metal flow restrictor plug 126 is interposed in the passage 232 " at the distal end of the shaft portion 213 to form the aforementioned flow restrictor

or timing orifice for the valve 116. Accordingly, when pressure fluid is supplied by way of the port 168 into the bore 164 , pressure fluid is communicated to the cavity 192 through the groove 230 , the passage 232 and the flow restrictor 126. As long as the pressure in cavity 192 is greater than approximately 60% of the valve fluid supply pressure or the pressure in bore 176 of valve 116 , the closure member 206 for valve 116 will be biased into the position shown in Figure 6 blocking flow of pressure fluid from the bore 164 into the bore 152. The valve 118 is provided with an identical closure member

206, and the pilot actuator 131 is also characterized by the assembly of rolling diaphragm members 218 , 220 and the support member 224. The pilot actuator 131 is operable to bias the closure member 206 of the valve 118 into engagement with the valve seat surface 160 in response to pressure fluid being introduced into a cavity 193 formed in and between a cover member 199 and the intermediate body part 188 of the .valve 118. The closure member 206 of valve 118 is normally biased into the position shown in Figure 6 by coil spring 125 absent the presence of pressure fluid being communicated to the valve 118 through a transfer port 155 formed in the body part 150 and opening into the respective bores 152 and 166.

The respective body parts of the valves 116 and 118 are secured in assembly by spaced apart elongated threaded fasteners 191 which extend from the respective cover members 190 and 199 through cooperating bores in the body parts and into cooperating internal threaded portions in the body parts 172 to hold the respective body parts in assembled relationship.

The operation of the valves 116 and 118 in the control circuit illustrated in Figure 5 is believed to be readily understandable from the previous description of the operation of the exterminating apparatus 10. The closure members 206 of the respective valves 116 and 118 are normally biased into their positions shown in Figure 6 when pressure fluid is being supplied to the valve 116 through the port 168. However, in response to actuation of the pilot pressure relief valve 128 to vent pressure fluid from the cavity 192 , the closure member 206 of valve 116 will shift from the position shown into engagement with the valve seat 158 blocking communication

between the bores 152 and 176 and communicating pressure fluid from the port 168 through transfer port 155 into bore 166 and also a passage 157 to the valve 120. Since the closure member 206 of valve 118 is normally biased into engagement with the seat 162 pressure fluid will flow directly from the bore 166 through bore 154 and port

170 into the chamber 22 of the actuator 18. Pressure fluid is also communicated through the groove 230 , passage 232 and flow restrictor 130 of valve 118 into the cavity 193.

After a suitable time delay to allow fluid pressure to increase in the cavity 193 , the pilot actuator 131 will operate to shift the closure member 206 of valve 118 into engagement with the seat 160 blocking the flow of pressure fluid to the actuator 18 and venting the actuator chamber 22 through port 170 , and the bores 154 and 176 to the exhaust port 180 to allow the striking bar 56 to move back to its retracted position. Moreover, the closure member 206 of valve 118 will remain engaged with the valve seat 160 as long as the closure member 206 of valve 116 is biased against seat 158. However, once the detector plate 70 is clear to allow it to return to its normal position the valve 128 will be allowed to close to permit pressure to increase in cavity 192 resulting in shifting of the closure member 206 of valve 116 into engagement with seat 156 to shut off the supply of pressure fluid to valve 118 and venting the bore 166 , transfer port

155 , and bores 152 and 176 to atmosphere through the exhaust port

180 of the valve 116. Venting of the bore 166 will allow cavity 193 to be vented through the aforedescribed passages in the closure member

206 so that the coil spring 125 will again bias the closure member of valve 118 against seat 162.

The valves 116 and 188 may, of course, be formed as separate structures and are not required to share the common body structures described, although this is advantageous in certain modular valve arrangements. A unique aspect of the valves 116 and 118 pertains to the provision of the body parts 150 , 172 , 188 , 190 , and 199 of injection molded plastic in finished condition, as molded, and of a suitable plastic such as an ABS composition. In like manner, the closure member 206 is formed of an integrally molded

ABS core member 210 which is then molded in assembly with the plug portion 208 which is preferably of a soft plastic such as a

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polyurethane composition to permit fluid-tight sealing engagement of the closure member with the respective seat surfaces of the valves 116 and 118.

Referring now to Figures 7 and 8, the valves 120 and 122 are shown in assembly with each other and with a manifold member

250. The manifold member 250 supports both valves 120 and 122 by elongated screws 252 , Figure 8 , which extend between the valves 120 and 122. The manifold member 250 is also adapted to secure the assembly of the valves 116 , 118 , 120 and 122 to the cylinder member 20 by suitable threaded fasteners 256 which extend through the manifold member, and through suitable clearance holes 258 , Figures 6 and 8 formed in respective ones of the body parts 150 and 172 as shown.

The valves 120 and 122 may be of identical construction and are adapted to perform the respective functions of a three-way valve

^" and an on/off or two-way valve, respectively. The valve 120 , for example, includes a molded plastic body part 260 having opposed bores 262 and 264 which are delimited at one end, respectively, by conical seat surfaces 266 and 268 , respectively. The seat surfaces 266 and 268 extend to a reduced diameter bore portion 270 which has opposed passages 272 and 274 opening into the interior of the valve body part 260. The passage 272 is in communication with a suitable tube fitting 273 which is supported on the body part 260 and is connected to one end of the conduit 107. The body part 260 also includes a passage 276 opening to the exterior of the valve 120 from the bore 264 by way of a muffler plug 277. The valve 120 also includes body parts 278 , 188 and 282 which make up the valve assembly and are also preferably finish formed of molded plastic except for internal thread forms as indicated herein. The valve 120 includes an elongated closure member shaft 284 disposed in the bores

262 and 264 and adapted to support opposed cylindrical closure member disks 286 and 288. The disks 286 and 288 may be separately molded of polyurethane or the like, for example , and forcibly mounted over reduced diameter shaft portions 289 and 291 , respectively, upon assembly of the shaft 284 with respect to the body part 260. The closure disk 286 is also preferably molded integral with a modified flexible rolling diaphragm 318. As shown by the position of the shaft

284 in Figure 7 , the closure disk 288 is in sealing engagement with the seat surface 266.

In response to axial shifting of the shaft 284 in a downward direction, viewing Figure 7 , the closure disk 288 will move away from the seat 266 and the closure disk 286 will engage the seat 268 to block communication of the valve chamber formed by the bore 264 from communicating with the passages 272 or 274. In like manner, when the closure disk 288 is engaged with the seat 266 the chamber formed by the ^' bore 262 is blocked from communicating with the passages 272 or 274. The closure member shaft 284 is connected to pressure fluid pilot actuator 133 comprising an assembly of the diaphragms 318 , 220 and the support member 224 all suitably mounted on shaft portion 289 in substantially the same manner as the arrangement of the pilot actuators 124 and 131. The diaphragm 318 is secured between the valve body parts 260 and 188 and the diaphragm

220 is secured between the body parts 188 and 280. The body part 280 defines an interior chamber 290 which is in communication with a passage 292 opening to the exterior of the body part 280 and in communication with a passage 294 formed in the manifold member 250. In like manner, the passage 274 is in communication with a passage

296 in the manifold member 250, and the bore 262 is in communication with a passage 298 formed in . the body part 260 and opening to a passage 300 also formed in the manifold member 250. The passage 300 opens to a manifold sidewall 251 , Figure 8 , and is in communication with passage 157 in the valve body part 150. The manifold member

250 is provided with suitable recesses for supporting resilient seal rings 295 , 297 , 299 , 301 and 303 , respectively, for sealing the points of communication of the passages 294 , 296 and 300 with respective passages in the valves 120 and 122. The closure member shaft 284 includes an elongated passage

302 extending therethrough and fitted with a flow restrictor element 137 similar to the flow restricting elements 126 and 130 and operable to restrict flow of fluid from the chamber 263 , formed by the bore 262 , to the chamber 290. The closure member assembly of valve 120 comprising the shaft 284 and the closure disks 286 and 288 is biased into the position illustrated in Figure 7 by a coil spring 125 disposed in a suitable recess 308 formed in the body part 278. In response to

the introduction of pressure fluid into the chamber 263 from the passages 300 and 298 , pressure fluid will flow through the passage 302 and into the chamber 290 at a restricted rate until pressure increases in the chamber 290 sufficiently to shift the valve 120 from the position illustrated to a position wherein the closure member 286 is engaged with the seat surface 268. In this position pressure fluid may flow from the chamber 263 through passage 272 to the actuator 96 to -effect actuation of the ejector gates 82 and 84 to sweep the detector plate 70 clear of an expired rodent, for example. The valve 122 is virtually identical in construction to the valve 120; however, the passage 272 is fitted with an exhaust muffler plug 277 , the passage 302 is blocked with a solid plug 311, the passage 292 is fitted with a flow restrictor 139 similar to flow restrictors 126 , 130 , and 137 and the passage 276 is blocked by a plug 313. The passage 274 is also blocked by manifold wall 253. The passage 292 of valve 122 is in communication with passage 274 of valve 120 by way of manifold passage 296. The valve 122 is arranged with respect to the valve 120 to effect venting of the pilot actuator 133 after a suitable time delay in response to movement of the closure disk 288 of the valve 120 from the position shown in Figure 7 to a position to permit flow of pressure fluid to the ejector actuator 96. For example, in the position illustrated in Figure 7 , the valve 122 is in a closed position with respect to venting the chamber 290 of valve 120. However, when the closure members 286 and 288 of valve 120 shift to the alternate position described above to communicate pressure fluid to the actuator 96 pressure fluid is also conducted through passage 274 of valve 120 , passage 296 in the manifold 250 and passage 292 of valve 122 into its chamber 290. Although fluid pressure has increased in the chamber 290 of valve 120 and is being communicated through passage 294 into the chamber 263 of valve 122 the nominal working pressure acting on the pilot actuator 135 of valve 122 will, after a suitable time delay, shift its closure member assembly to the position wherein closure disk 288 has moved away from its cooperating seat surface 266 to vent the chamber 263 of valve 122 through its passage 272. Accordingly, in response to shifting of the valve 120 to conduct pressure fluid to the actuator 96 , after a suitable time delay, the pilot actuator 133 is vented and the valve 120

returns to the position wherein its closure disk 288 is in sealing engagement with the seat 266. In this position of valve 120 , which is the one illustrated in Figure 7 , the passage 272 is vented to atmosphere through passage 276. At the same time fluid pressure in chamber 290 of pilot actuator 135 is relieved through passage 296 and the closure disk 288 of valve 122 returns to engagement with seat surface 266.

The valves 120 and 122 are each secured in assembly of their respective body parts 188 , 260 , 278 and 280 by elongated flat head self tapping screws 310 which extend through cooperating clearance bores in the respective members and are threaded into suitable holes in the members 278. Accordingly, the valves 120 and

122 are of similar construction with regard to the valves 116 and 118.

An important aspect of the construction of the valves 120 and 122 resides in the provision of an axially projected face area of the diaphragms 220 exposed to pressure fluid in the respective chambers 290 greater than the effective axially projected face area of when the closure disks 288 when exposed to fluid pressure in the chambers 263 the closure disks 288 are in sealing engagement with the seat surfaces 266 whereby, when equal pressures are acting on the closure disks 288 and the diaphragms 220 , the pilot actuators 133 and

135 will be effective to shift the closure assembly of the shaft 284 and the closure disks 286 and 288. The effective face areas of the diaphragms 220 which are operable to shift the valves 116 , 118 , 120 and 122 may be selected to effect actuation of the valves by their respective pilot actuators when pressure in the pilot actuators reaches approximately 60% of the nominal working fluid pressure of the control circuit.

Those skilled in the art will appreciative from the foregoing discussion that a particularly novel arrangement has been developed of a plurality of control valves and a control circuit for the rodent exterminating apparatus of the present invention. As mentioned above, the valves 116 , 118 , 120 and 122 are particularly adapted to be manufactured at low cost using injection molded plastic for fabricating the respective valve body parts and the support manifold 250. Moreover, the fabrication of other components such as the closure member shaft , plug and disk components and the diaphragms

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318 and 220 utilizing molded plastic materials also reduces the manufacturing costs of the respective valves. The reduced weight of the closure member assemblies and the superior fluid sealing characteristics of the closure member plugs and disks described herein also contributes to the shifting speed of the valves and the elimination of unwanted fluid leakage flow. This latter feature is particularly desirable to maintain the timing and sequential operating characteristics of the control circuit for the rodent exterminating apparatus and to minimize the loss of pressure fluid when the source is a fixed supply such as a compressed air bottle or reservoir. In this regard isolated installations of the apparatus 10 may be permitted to operate through a substantial number of operating cycles without unwanted loss of working fluid.

Although a preferred embodiment of the rodent exterminating apparatus and the valve module 64 have been described herein in conjunction with the drawing those skilled in the art will appreciate that various substitutions and modifications may be made to the embodiments disclosed without departing from the scope and spirit of the invention as recited in the appended claims.

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