Field of the invention

The present invention relates to a penetration device for use in fire-fighting operations, in particular in the context of airport rescue.

Description of the prior art

Penetration devices associated with the tip portion of a telescopic cantilever arm or with the tip portion of a boom of an emergency vehicle are known.

An example of penetration tool is given in US7055613.

The penetration device comprises a movable punch having a tapered shape for piercing through a body wall and a nozzle for introducing a fire-retardant or fire-extinguishing medium into an interior space of the body through the penetration tool .

Thus the movable punch is substantially tubular shaped, with its interior portion connected in line to a fire- retardant/extinguishing medium tank.

Several drives or hydraulic actuators can be used in order to adjust the orientation of the penetration tool.

Another example of penetration device is given in EP1980294.

Such penetration device has an inner tubular element associated with an outer tubular element. The latter being fixed with the tip of a boom. The inner element, as usual, has a tapered end and is sliding associated to the outer element.

In order to achieve the required stability of the inner element with respect to the outer element, the inner element has a relevant development length, that is substantially double with respect to the outer element.

Figure 1 of the prior art shows a sketch of the known solution from EP1980294.

This implies a relevant size of the overall penetration device and a relevant weight.

Summary of the invention

Therefore it is the main object of the present invention to provide a very compact but effective penetration device which overcomes the above problems/drawbacks, with a relevant reduction of space and weight.

The main principle of the invention is the arrangement of three tubular, reciprocally coaxial, elongated members: inner, middle, outer element, with the inner member and the outer member being fixed between each other; the middle member has a first tapered end and a second opposite end, the first end defining a punch; the middle member being coaxially movable between a retracted and an elongated condition with respect to both the inner and outer elements, wherein the inner and the middle members define a pipe for the retarder/extinguishing medium, and wherein the outer member cooperates with said second end of the middle member to define a double-acting pressure cylinder for the middle member .

Both the inner and outer members define a sliding guide for the middle member, by assuring a high stability for the middle member, that, thus, can have a development length similar with respect to the development length of the inner and outer members .

A first object of the present invention is a penetration device according to claim 1.

Another object of the present invention is a firefighting vehicle provided with said penetration device.

These and further objects are achieved by means of the attached claims, which describe preferred embodiment of the invention, forming an integral part of the present description .

Brief description of the drawings

The invention will become fully clear from the following detailed description, given by way of a mere exemplifying and non limiting example, to be read with reference to the attached drawing figures, wherein:

Fig. 1 shows a longitudinal section view of an example of penetration device according to the present invention;

- Fig.2 shows an example of control circuit for controlling the penetration device in different operation stages;

The same reference numerals and letters in the figures designate the same or functionally equivalent parts.

According to the present invention, the term "second element" does not implies the presence of a "first element", first, second, etc.. are used only for improving the clarity of the description and should not be interpreted in a limiting way.

Detailed description of the preferred embodiments

According to figure 1 an example of penetration device according to the present invention is shown.

It comprises, substantially, three hollow tubular members OC, MC, IC, coaxially between each other and defining a development axis X.

With the exception of the presence of openings C1C and C2C, it is preferable that the penetration device P is axially symmetric along the X-axis.

The inner IC and outer OC tubular members are fixed between each other through a first end FE of the device, the right side of figure 1. The coupling of the inner member and outer member define a fixed member FP of the device P, suitable to be associated with tip of an arm of a boom of a rescue vehicle.

The middle member MC defines the movable member of the device P.

An annular wall Wl connecting the inner and outer members at the first end FE of the device can be integral with one or both of the same members IC, OC, in order to define an annular chamber.

The middle tubular member MC is interposed between the inner and outer members, being suitable to slide coaxially through the second end SE of the device.

Also the middle member comprises two opposite ends, one of those being tapered to define a punch MCT, the opposite end MCO being hollow tubular shaped.

The tapered portion of the middle member MC protrudes outwards through the second end SE of the device P.

One or more nozzles MCN are realized at the tapered portion of the middle member, communicating the internal volume bounded by the middle member itself with the outside.

The inner and outer members define two guides for the middle element in connection with its sliding capability.

Said middle member MC is suitable to define two extreme conditions: a first retracted condition and a second elongated condition: figure 1 shows an intermediate condition .

Said opposite end MCO of the middle member MC comprises at least one seal, in order to define a seal assembly, both with the outer member and with the inner member. The seal assembly between the inner member and the middle member defines a pipe for injecting extinguishing or retarding fluid through the nozzles MCN.

The seal assembly between the middle member and the outer member divide the annular chamber into two portions CI and C2. CI, adjacent with respect to the first end FE of the device, acts on the hollow tubular end MCO of the middle element by pushing it outwards with respect to the device to assume said elongated condition when pressurized by means of a hydraulic fluid introduced in CI through the opening C1C. C2, adjacent with respect to the second end SE of the device, acts on the end MCO of the middle element by pushing the middle member MC inwards with respect to the fixed portion FP of the device, to assume said retracted condition when pressurized by means of a hydraulic fluid introduced in C2 through the opening C2C.

The whole volume of CI is bigger than the one of C2 due to a different inner diameter of the chambers.

This implies that the cross section area of CI is wider than the cross section area of C2.

Thanks to the presence of both the inner and outer member to define a sliding guide for the middle member, the axial length LM of the latter is similar/comparable with the axial lengths LI and LO of the inner and outer members respectively, by assuring the same stability and the same elongation of the device shown in EP1980294. However, the movable member shown in EP1980294 has a double length with respect to the length of the movable member according to the present invention, by considering the same elongation in the elongated condition.

The outer member, at the second end SE of the device, comprises a second annular wall W2 provided with a seal S in order cooperate with the inner member in defining said second chamber C2.

It should be noted that, even if the hydraulic chamber

C2 is defined between the middle member MC and the outer member OC, it could be defined between the inner member IC and the middle member MC . In such a case, the second annular wall W2 would be fixed with the inner member IC and the second opening C2C should be realized through the inner member .

According to a preferred embodiment of the invention, the inner end MCO of the middle member MC has an enlarged section ES operatively associated with the inner annular seal S2 arranged in close position with respect to the second annular wall W2, within the chamber C2.

Between the outer member OC and the annular seal S2 is defined a narrow passage for the hydraulic medium. In addition, the opening C2C is arranged between the second annular wall W2 and the annular seal S2. The enlarged section ES at the inner end MCO of the middle member MC is realized in order to cooperate with the annular seal S2. In particular, when the enlarged section ES of the middle member MC contacts annularly the annular seal S2 during a penetration operation, the hydraulic medium is forced to pass through the narrow passage PSS in order to leave the chamber C2 through the opening C2C. In this way, a cushioning effect is obtained in order to reduce the speed of the middle member MC when it is going to reach the maximum elongated condition, by avoiding any mechanical damage.

The first end FE of the device P defines, with the hollow portion of the inner member, a coaxial opening CO suitable to be connected to a source of fire-retardant and/or fire-extinguishing medium.

Figure 2 shows a preferred embodiment of an implementation of the device P of the present invention.

The penetration device is mounted on the tip of a telescopic boom 15, adjustable around a horizontal axis 14 by a hydraulic pivot drive 12.

The pivot drive 12 is controlled by a proportional directional valve 13, preferably integrated into the main hydraulic bench of the boom and mounted at the base of the basic boom.

A switch valve 11, instead, is mounted at the tip of the telescopic boom 15. The switch valve 11 is suitable to commutate the connection between the hydraulic source S and the discharge tank T (not shown) with the hydraulic pivot drive 12 (first operator 11.1) or with the hydraulic chambers CI, C2 of the penetration device (second operator 11.2) .

The proportional directional valve 13, instead, is suitable to

interrupt the connection between the hydraulic actuators P, 14 and the source S/tank T - second operator 13.2 connect the hydraulic actuators P, 14 and the source S/tank T - third operator 13.3 - or to revert such connection - operator 13.1-.

A switch valve 16, instead, is mounted at the tip of the telescopic boom 15, and has

- a first port lp connected with the line LI,

- a second port 2p connected with the line L2,

- a third port 3p connected with the opening C2C and

- a fourth port 4p connected with the opening CIC.

In particular, while the first operator 16.1 connects the port lp with the port 4p and the port 2p with the port 3p, the second operator 16.2 connects the ports lp, 4, and 3p together, by closing the port 2p.

When, the third operator 13.3 of the valve 13, the second operator 11.2 of the valve 11 and the second operator 16.2 of the valve 16 are simultaneously activated, the hydraulic medium flows from the source S towards the chamber CI, that expands compressing the chamber C2, whose hydraulic medium herewith stored flows towards the third port of the second operator 16.2 to recirculate towards the first chamber CI. Thus the line L2 connected with the second port is bypassed, hence no hydraulic medium reaches the tank T.

This recirculation of the hydraulic medium is obtained also in view of the wider size of the chamber CI in comparison with C2.

In these conditions the hydraulic medium pressure is identical between the two chambers, but the force for elongating the middle member is bigger than the force for retracting. Thus, the oil expelled out from C2 is automatically recirculated in CI.

Even if the mass flow of hydraulic medium from the hydraulic source S is constant, this arrangement permits to increase the elongation speed of the device P.

When the operators 16.2, 11.2 and 13.1 are activated, the line L2, and thus the chamber C2 of the device P is pressurized, while the chamber CI is connected with the discharging tank T, thus the middle member is retracted.

When, the first operator 11.1 of the switch valve is activated, the third and fourth ports of the same operator 11.1 connect the opposite chambers (not shown) of the actuator 12 for pivoting the penetration device P around the pivoting axis 14, while the line connections LI and L2 towards the chambers CI and C2 are interrupted for locking the middle member MC .

In this case, one of the chambers of the hydraulic actuator 12 is connected with the source S when the operator 13.3 is activated and the other one is connected with the discharging tank T and vice versa when the first operator 13.1 is activated.

When the piercing cylinder, namely the middle member MC, is orientated correctly onto the fuselage of the airplane to be succored, the second operator 11.2 of the switch valve 11 is enabled to supply the piercing cylinder.

The stroke of the piercing cylinder is realized hydraulically through only one hydraulic source, i.e. a pump, without saving any hydraulic energy in any kind of pressure reservoir .

The device P could also provided with a further hydraulic drive to enabling its rotation around a vertical axis, so that it can be easily positioned orthogonally onto the wall to be penetrated.

In this case, the switch valve 11 can be provided with a further operator similar with the first operator 11.1.

Many changes, modifications, variations and other uses and applications of the subject invention will become apparent to those skilled in the art after considering the specification and the accompanying drawings which disclose preferred embodiments thereof. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by this invention.

Further implementation details will not be described, as the man skilled in the art is able to carry out the invention starting from the teaching of the above description.