This invention relates to the field of pressurized gas feeding systems, particularly compressed air feeding sy¬ stems, provided with one or more air receivers and more specifically the pneumatic systems used for operating the heavy industrial vehicles.

As well known, a considerable amount of water produced by condensation of the humidity always present in the atmo¬ spheric air deposits on the bottom of the air receivers. Such water deposit in undesiderable as it may cause even very serious damages both to the containing receivers and the compressed air utilizing systems. For instance, the water on the bottom of the reservoir can cause the oxida¬ tion and then the corrosion of the reservoir walls to be initiated. Furthermore, the water can be entrained into the conduits in which it may freeze in case of a low out¬ er temperature, thus causing the conduits to be occluded and broken with the tragic event which may result when said conduits are connected to the braking system of a heavy vehicle. It follows that the drainage of the water deposit from the air receivers, which is very expedient in case of stationary compressed air systems, becomes an absolute necessity in case of systems destined to heavy vehicles and mainly in ease of braking systems. Unfortunately there is at the time being no efficient de- vice carrying out automatically and with the desired fre¬ quency the drainage of the condensate deposits existing in the air receivers of the industrial vehicles. In most cases, however, each air receiver of an industrial

vehicle - it should be noted that each heavy vehicle has typically more than one air receiver, e.g. there are vehi¬ cles having six or more air receivers - is provided with a manual condensate drainage apparatus, typically a snift- ing valve. This rather primitive solution, which is not able for certain by itself to assure that the necessary drainage of the condensate deposits is carried out with the due reliability, is further impaired by the placement of the various air receivers under the frame of the vehi- cle in hardly accessible positions. It follows that the manual condensate drainage operation is usually carried out only in case the vehicle is stopped for repair or main¬ tenance reasons. Therefore, the gravity of the danger inherent to the lack of a periodic and frequent condensate drainage of the air receivers, which the heavy vehicles are equipped with, caused such vehicles to-be necessarily provided with- an automatic apparatus providing for such _. an operation. It should be noted that, since the condensate drainage causes necessarily the outlet of compressed air, the ope¬ ration of such an automatic apparatus has to provide for the opening of the valve devices being limited to the time strictly necessary for the drainage of the condensate in order to avoid the total leakage of the compressed air contained in the air receiver or most of it.

Failing this feature, i.e. the possibility of causing a

« very short opening of the condensate drainage valve in or¬ der to avoid the loss of compressed air from the air

receiver, the automatic condensate drainage apparatus of the present status of art available on the market are less efficient as they cause a leakage of the compressed air contained in the air receivers. Therefore, this invention seeks to provide an apparatus able to cause the condensate to be drained from all air receivers of an industrial vehicle with an optimized fre¬ quency and in an automatic manner when the motor of the vehicle is stopped, which is a typical and frequent oper- ation of the vehicle.

Another object of the invention is to provide an apparatus causing a short opening of the valves such as to reduce the leakage of compressed air from the air receivers to that which is strictly necessary. Still another object of the present invention is to provi¬ de a drainage valve device particulary able to be used in the automatically controlled apparatus for the conden¬ sate drainage from the air receivers. To accomplish the proposed objects the invention provides a compact, inexpensive, effective apparatus that, being connected by separate conduits to each condensate drainage outlet on the bottom of each air receiver and to an often operated member of the vehicle embodying the apparatus, causes the condensate to be drained when operating said member.

More exactly, it is described and illustrated an embodi¬ ment of the apparatus which is connected to the member that almost in the whole of the industrial vehicles con-

trols the stop of the motor by acting on the injection pump.

The apparatus for the automatic condensate drainage from the air receivers according to a preferred embodiment es- sentially includes: a drainage valve device provided in each air receiver of the vehicle with the relative piping system connected to the drainage opening of the receiver; a slide member operating at the same time all condensate drainage valve devices; a pneumatic double-acting cylinder and piston assembly having two charbers placed at the op¬ posite ends of the plunger in contact with the slide mem¬ ber operating the drainage valve devices; a first pipe connecting a first chamber of the pneumatic assembly to a compressed air source; a second pipe connecting the se- cond chamber of the pneumatic assembly to a compressed air source; a first two-position valve with rotatable valve member placed in the first connecting pipe; a second two- position valve with rotatable valve member placed in the ^' second pipe; a control means operating at the same time said first and second two-position valves and drivingly connected to the member acting on the injection pump of the motor in order to cause the latter to be stopped. I should be appreciated that the apparatus according to the invention carries out the drainage of all reservoirs wherever the various air receivers are placed in the vehi¬ cle as it will be apparent from the following detailed description. Furthermore, it should be noted that both two-position

valves drivingly connected to each* other are inserted in the respective pipes so that when one of them is in the position in which the compressing air flows towards the respective chamber of the pneumatic double-acting assembly, the other valve is in the opened position connected to the atmosphere, and viceversa. In operation, the control of the member causing the motor to be stopped allows the state of both two-posi¬ tion valves to be changed so as to cause a displacement of the plunger of the pneumatic double acting assembly with the consequence of a displacement of the slide member that controls, therefore, all drainage valve members to be changed from the steady closed position to the opened position, whereupon to a second transi- tory closed position, again to the opened position and finally to the steady closed position. The drainage valve device, which is an object of the present application too, essentially includes: a f ^' inned cylindrical casing; a frustum-conical on-off valve mem- ber; a valve stem operating the on-off valve member and connected to the latter; a valve return spring for the valve stem; and a splined cylindrical head integral with the frustum-conical valve member. The splined cylindrical head integral with the frustum- conical valve member is placed in the chamber of the valve casing connected to the air receiver from which the condensate has- to be drained and consequently said head is exposed to the latter.

Such cylindrical head, however, has a circular outer face and an inner face in form of a circular corona, the area of which is much smaller than the outer face, at the connection with the frustum-conical valve member so that,owing to the splines the air pressure acts on opposite surfaces having very different area as descri¬ bed into detail afterwards.

An embodiment and the operation of the apparatus accor¬ ding to the invention will be more readily apparent from the following description with reference to the accom¬ panying drawings, in which:

Fig. 1A is a general schematic view of the apparatus placed in an industrial vehicle having six air receiv¬ ers, the apparatus being in the steady closed position; Fig. IB is a similar view with the apparatus being in the transitory closed position;

Fig. 2 is a perspective, fragmentary view ^" showing in enlarged scale both two-position valves and the control member; Fig. 3 is an axial, fragmentary section showing in en¬ larged scale one of the condensate drainage valve mem¬ bers in the closed position;

Fig. 4 is a similar view with the condensate drainage valve members in the opened position; and Fig. 5 is a view similar to the Figs. 1A and IB of a second embodiment of the apparatus;

Fig. 6 is an axial section of the condensate drainage valve device in the closed position; and

Fig. 7 is a seciton of the valve device in the opened position.

Referring particularly to the Figs. 1A and IB the appa¬ ratus according to the invention essentially includes: six condensate drainage valve members preferably arran¬ ged on two rows of three valve members each generally designated by 10A - 10F and connected each to the drain¬ age opening of the respective reservoir 11A - 11F by means of a piping system 12A - 12F, respectively; a H-shaped slide member operating at the same time the valve members 10A - 10F and generally designated by 30; a pneumatic double-acting cylinder and piston assembly 40; a first pipe 50A feeding compressed air to a first chamber of the pneumatic assembly; a second pipe 50B feeding compressed air to the second chamber of the pneumatic assembly; a first two-position valve 60A pla¬ ced in the pipe 50A; a second two-position valve 60B placed in the pipe 50B; and a control member designat¬ ed by 70 and operating at the same time both two-posi- tion valves.

It should be noted that the six valve members 10A - 10F, the slide member 30 and the pneumatic assembly 40 are preferably arranged in the same casing CE designated by the dashed lin in the Figs. 1A and IB. The essential feature of the apparatus of the invention is to drain the condensate in very short time in order to avoid the loss of large amounts of compressed air from the reservoirs. That being stated, the valve member

10A - 10F have been designed to accomplish this object and each of them has the embodiment illustrated in the Figs. 3 and 4.

As a matter of fact each valve member generally design- ated by the numeral 10 includes: a cylindrical casing having two chambers 14A and 14B separated by a central¬ ly opened partition 13 and closed by a cover 15A and 15B, respectively; a piston 16 provided with a collar 18 having a flattened end 19 at the outer side of the co- ver 15A and an inner, axially splined end 20, said pi¬ ston being slideable into the bores of the cover 15A and the partition 13; a valve spring 21 arranged on the piston 16 and acting as a compression spring bet¬ ween the collar 18 and the partition 13; a valve seat 22 formed in the chamber 14B; a ball valve member 23 placed in the chamber 14B so as to seal the valve seat 22; a spring 24 acting as a compres.sion spring between the ball valve member 23 and the inner face of the co¬ ver 15B; a pipe fitting 25 integral with- the cover 15B and a drainage branch pipe open to the atmosphere.

As clearly illustrated, the valve seat 22 divides the chamber 14B into an inner space 27A communicating with the atmosphere through the branch pipe 26 and in which the end 20 of the piston 16 is arranged, and an outer space 27B communicating with the pipe 12 through the pipe fitting 25 and then with the respective air recei¬ ver 11, in which space the ball valve member 23 and the spring 24 are arranged.

It is useful to note that the piston 16 can sealingly slide into the central bore of the partition 13. Turning now to the Figs. 1A and IB the slide member 30 operating the valve members 10A - 10F is arranged bet- ween two rows of the latter and consists of a H-shaped frame having two arms 31A, 31B parallel to each other and a central traverse 32.

The one ends 33A - 33C of three link rods 34A - 34C are linked with the arm 31A, while the other ends 35A - 35C are linked with the ends 19A - 19C of the pistons of the relative con4ensate drainage valve members 10A - IOC, respectively.

Likewise, the three.link rods 34D - 34F of the arm 31B are linked with the ends 19D - 19F of the pistons of the relative condensate drainage valve members 10D - 10F, respectively.

Further the H-shaped slide member 30 guided in two pairs of fixed guide members 36A, 36B is _. restrained ^' to move only in an axial direction with respect to the casing CE since the cross movements thereof are prevented. The end 41 of the piston 42 of the pneumatic double- acting cylinder and piston assembly 40 is connected to the central traverse 32. Such pneumatic assembly 40 further includes a cylindri- cal casing 43 in which the plunger 44 dividing as well known the inner cavity of the cylinder into two chambers 45A and 45B is sealingly slideable. The chamber 45A has a pipe fitting 46A for the supply of compressed air

as well as the chamber 45B has a similar pipe fitting designated by 46B.

As mentioned above the pipe fitting 46A is connected through the pipe 50A to the first two-position valve 60A and the pipe fitting 46B is connected through the pipe 50B to the second two-position valve 60B. As clearly illustrated in the Figs. 1A and IB the pipes 50A and 50B are supplied with compressed air from one of the air receivers 11A - 11F and in the present case from the air receiver 11A through the pipe 51.

Both valves 60A, 60B of well known type have the same structure and include each a hollow cylindrical casing 61A, 61B having first and second pipe fittings 62A, 62B and 63A. 63B. respectively connected to the outside and diametrally opposite each other, and a third pipe fitting 64A, 64B connected to the outside and arranged at an angular displacement from the first pipe fitting 62A,.62B. A ^' solid cylindrical body 65A, 65B placed within the ca- sing 61A, 61B is provided with a diametral passageway

66A, 66B at one end of which a chamber 67A, 67B is pro¬ vided having an angular amplitude equal to the angle between the pipe fittings 62A. 62B and 64A. 64B. respec¬ tively. Each solid cylindrical body 65A. 65B can move within the respective hollow cylindrical casing 61A, 61B by an angular displacement equal to the amplitude of the chamber 67A, 67B, respectively, this movement being

controlled from the outside.

As better illustrated in Fig. 2, both solid cylindrical bodies 65A, 65B of the valves 60A, 60B are driven by one shaft 68. Furthermore the two-position valves 60A, 60B are arranged so that when the diametral passageway 66A of the solid cylindrical body 65A connects the pipe fittings 62A and 63A to each other, the diametral pas¬ sageway 66B of the other solid cylindrical body 65B is turned with respect to the position of the former, and viceversa.

Therefore, as clearly illustrated, the chambers 67A and 67B, connect the adjacent pipe fittings 62A, 64A and 62B, 64B, respectively, when the diametral passageway 66A and 66B are turned with respect to the position in which they connect the pipe fittings 62A, 62B to the pipe fittings 63A, 63B. respectively. The control shaft 68 of the rotating bodies 65A, 65B is integral with a lever arm 69, at the other end of which the free end of a piston 71 operated by a member 70 controlling at the same time both valves 60A, 60B is connected.

In the embodiment of the invention herein illustrated and describe the control member 70 is consisting of the pneumatic cylinder and piston assembly that in a well known manner controls in the most of heavy vehicles the turning off of the motor acting on the rackwork of the injection pump. It is to be intended, however, as repeated afterwards,

that such control member car} consist of any other pneu¬ matic, electric, electromagnetic, hydraulic or mechanic 'control member which can perform the same function of the control member 70 described herein. The operation of the apparatus according to the inven¬ tion is as follows:

Under normal running conditions of the vehicle the con¬ trol member 70 is in the position of Fig. 1A, in which it is resili.ently urged, for example, by the spring ML. Consequently all members of the apparatus are in the position illustrated in the above mentioned figure. More particularly, the compressed air of the receiver 11A, that reaches the chamber 45A of the pneumatic dou¬ ble-acting assembly 40 through the pipes 51 and 50A and the diametral passageway 66A connecting in the through postion the pipe fittings 63A and 62A and clos¬ ing the pipe fitting 64A, holds the plunger 4.4 and the slide member as well' in their shifted positions on the extreme left in Fig. 1A. It is to be noted that due to the position of the solid cylindrical body 65B the chamber 45B is connected to the atmosphere through the left length of the pipe 50B. the pipe fitting 62B. the chamber 67B and the pipe fit¬ ting 64B. The operation of the pneumatic assembly 70. initiated as it is known by the opening of the pneumatic valve VP through the pipe TT (Fig. 2) in order to turn off the motor of the vehicle, will cause a stroke to the

right of the piston 71 of the assembly 70 (Figs. IB and 2) and then a rotation in the clockwise direction of the solid cylindrical bodies 65A, 65B controlled at the same time by the shaft 68 to the position illustrated in Fig. 2.

Consequently, the compressed air of the receiver 11A rais¬ es the pressure of the chamber 45B of the slide member 40 through the pipe 51 and the whole length of the pipe 50B owing to the position held by the diametral passage- way 66B connecting now the pipe fittings 63B and 62B and closing the pipe fitting 64B (Fig. IB).

Since the chamber 45A is at the atmospheric pressure as the compressed air is blown off in the atmosphere through the left length of the pipe 50A, the pipe fitting 62A, the chamber 67A and the pipe fitting 64A, the plunger 44 moves rightwards in the figure trailing in the same di¬ rection the stem of the piston 42 and the slide member 30. The rightward movement of the slide member 30 causes the movement of the link rods 34A - 34C and 34D - 34F from the position inclined with respect to the axis of the respective arms 31A and 31B (see Figs. 1A and 3) to the position perpendicular to the latter (Figs. IB and 4). Therefore, all pistons 16A - 16F move from the position of Fig. 3, in which the ball valve member 23 is pres¬ sed against the valve seat 22 so as to seal the passage¬ way between the chamber 27B and the chamber 27A, to the position of Fig. 4, in which the head 20 of the piston

pushes the ball 23 to move away from the seat 22 against the spring 24. Therefore, the condensate on the bottom of the air receivers 11A - 11F and in the pipes 12A - 12F is quickly expelled into the atmosphere through the cham- ber 27B, the chamber 27A and the branch pipe 26.

It should be appreciated that the opening time of the as¬ sembly of the ball valve member 23 and the seat 22 is ra¬ ther short as the continuation of the stroke of the slide mem¬ ber 30 rightwards causes the latter (and then the link rods 34A - 34F) to move to the position illustrated with dashed lines in Fig. IB, in which the seats 22 are sealed again from the balls.23 because of the retraction of the pistons 16A - 16F. At this moment, in the typical operation of the diesel engine the pneumatic assembly 70 is moved again by re¬ turn spring ML to the position taken during the normal run.- ning of the vehicle. This will involve a back stroke leftwards of the slide member 30 with the consequence of a transitory opening of the assembly 23-22 when the link rods 34A - 34F move to the positions of the Figs. IB and 4, and an immediate closure when they come back to the positions illustrated in the Figs. 1A and 3. Therefore, each turning off of the vehicle motor will cause a double-acting drainage of the condensate from all air receivers 11A - 11F. In Fig. 5 it is illustrated a second embodiment of the invention, in which the construction formed of the pneu¬ matic double-acting cylinder and piston assembly 40 and both valves 60A, 60B is replaced by two bellow chambers 140A, 140B having control members with different diame-

ters.

As well known by itself each bellow chamber 140A, 140B includes an outer casing 143A, 143B, which is provided with a pipe fitting 146A, 146B for the supplying of the compressed air and within which a control member 144A, 144B is movable together with a bellow 148A, 148B, the latter being connected at one end to the former and at the second end to the bottom 149A, 149B of the respecti¬ ve chamber 140A, 140B. For the operation of this embodiment it is sufficient to mention that under normal running conditions of the vehi¬ cle r the control members 144A, 144B, ' the slide member 130 and all the other components of the apparatus are in the positions illustrated by dashed lines, as the compressed air from the air receiver HID through the pipe 160B acts on the inner surface of the control member 144B. The stop of the motor will cause the pneumatic valve VP to be operated and to convey compressed air through the pipe 160A and the pipe fitting 146A within the bellow 148A which will expand and push the control member 144A leftwards in Fig. 5. Also the piston stem 142, the traver¬ se 132 and the slide member 130 will move with the con¬ trol member 144A. This displacement will cause the move¬ ment of the link rods 134A - 134F as already described with the consequent on-off of the valve member 110A - 110F.

As it will be apparent to the skilled in the art the dis¬ placement of the slide member 30 can be provided by means

of different control members of electric, electromagnetic, mechanic, hydraulic type without departing from the scope of the invention.

In the Figs. 6 and 7 parts of the valve device equal or similar to those shown in the foregoing Figs. 1A to 5 are designated by the same reference numerals increased by 200.

As clearly illustrated each cylindrical casing 210 has on one side a closed chamber 214B and a cover 215B and on the other side a cylindrical cavity 214A counterbored at its end 215A; a valve stem 216 provided with a collar 218 having a flattened end 219 outside the end 215A of the casing 210 and an inner end 220 connected to a fru¬ stum-conical valve member 223, said stem 216 being sli- deable in the cavity 214A; a spring 221 arranged on the stem 216 and acting as a compression spring between the collar 218 and the bottom 213 of the counterbore 2.15A; a valve seat 222 formed in.the chamber 214B; a frustum- conical valve member 223 arranged in the chamber 214B so as to seal the valve seat 222; a pipe fitting 225 inte¬ gral with the cover 215B and a branch pipe 226 open to the atmosphere.

As clearly illustrated, the valve seat 222 divides the chamber 214B into an inner portion 227A connected to the atmosphere through the branch pipe 226, in which the end 220 of the stem 216 is received, and an outer portion 227B connected through the pipe fitting 225 to the pipe 212 and then to the respective air receiver 11, in which

portion 227B both the valve member 223 and the cylindric¬ al head 224 are received.

The surface of the cylindrical head 224 has splines 224B causing the air pressure from the pipe 212 to act besides on the circular head 260 also on the annular surface 261 surrounding the frustum-conical valve member 223. With such an arrangement the force on the circular head 260 is partially compensated by that on the annular surface 261. Likewise to what already illustrated and described above the slide member 230 controlling the valve members is ar¬ ranged between the two rows of the latter and is formed of a frame .231 linked to one end 233 of the link rod 234, the other end 235 of which is linked to the end 219 of the stem 216 of the condensate drainage valve device 210. It is important to be noted that the link between the end 235 and the flattened end 219 is carried out by means of a pin 235C received into a slot 235D of the end 219, thus forming a clearance which will avoid the necessity of a strict tolerance of manufacturing of the single components. As all parts described and illustrated herein are of the same structure, arrangement and operation as described above, the operation of the valve device will be briefly described herebelow. The forward stroke (arrow F_) of the slide member 231 in the axial direction will cause through the link rod 234 moving from the oblique position A of fig. 6 to the per¬ pendicular direction B of Fig. 1, a reciprocating motion

of the stem 216 so that the valve member 223 will move away from the valve seat 222, thus allowing the outlet of the condensate into the atmosphere throuqh the branch pipe 226. The valve member 223 will seal then the valve seat 222 when the link rod 234 moves to the position C. Likewise the valve member 223 will open during the return stroke (arrow F2) of the slide member 231 when the link rod 234 moves to the position B and will then close stead¬ ily (position A held up to the new operation) at the end of such a return stroke.

It should be appreciated that the movements of the valve stem 216, and then of the valve member 223, are made very smooth and are cushioned by the action of the compressed air on the annular face 261 besides being promoted by the spring 221. Such feature avoids any troublesome striking noise of the valve member 223 against the valve seat 222. To this end an inserted valve seat could be used, as shown in the figures, for example made of either a diffe¬ rent metal than that of the valve casing or of a plastic material.

As it is evident in the figures, the two lengths of the cylindrical valve casing separated by the branch pipe 226 are finned, as designated by 262, in order to dissi¬ pate the heat more quickly. From what above it is clear that the present invention fully accomplishes the above mentioned objects.