Pneumatic telescopic mast

Abstract

A pneumatic telescopic mast (1), which is used, for example, to support and move military communication equipment, lighting equipment and / or surveillance equipment. The pneumatic telescopic mast includes a plurality of telescopically coupled sealed tubes. The driving of the tubes is achieved by introducing pressurized air into the pneumatic telescopic mast. Tube locking means are provided which lock the tubes in the extended configuration by interference or friction even when there is no pressurized air in the mast. The tube locking means include at least one safety means which is configured to keep the tube locking means in the locked position and which can only be deactivated to allow the tube locking means to switch to the released position when the air in the mast reaches a preset pressure value.

Description

Technical Field

[0001] The present invention relates to a pneumatic telescopic mast, which is used, for example, to support and move military communication equipment, lighting equipment, and / or surveillance equipment. Background Art

[0002] As is well known, a pneumatic telescopic mast consists of a plurality of telescopically joined sealed tubes (also referred to as "components"). These tubes are operable to switch from a retracted configuration to an extended configuration and vice versa. The driving of these tubes is achieved by introducing pressurized air into the pneumatic telescopic mast.

[0003] Certain types of telescopic masts related to the present disclosure are provided with a locking system for the extended tubes, such that the mast can remain extended even without pressurized air in the mast. These locking systems typically operate by interference or friction to hold these components together.

[0004] The disadvantage of this type of pneumatic telescopic mast is that when the mast is extended, an inexperienced or inattentive operator may risk unlocking the locking system without using the precautions described in the instruction manual and maintenance manual. Most frequently, the locking device, which is typically integral with the fixed lower tube, is deactivated without first pressurizing the mast itself. Obviously, this situation can be very dangerous and should be avoided. Other examples of pneumatic telescopic masts are disclosed in WO2011 / 163585A1 and DE2454271A1. Summary of the Invention

[0005] The object of the present invention is to provide a pneumatic telescopic mast that can avoid this disadvantage.

[0006] The basic idea of the present invention is to prevent one or more locking devices of the tubes from being deactivated until the air in the mast reaches a preset pressure level.

[0007] The pneumatic telescopic mast includes a plurality of telescopically joined sealed tubes. These tubes are operable to switch from a retracted configuration to an extended configuration and vice versa. The driving of these tubes is achieved by introducing pressurized air into the pneumatic telescopic mast. The mast is provided with tube locking devices that are adapted to lock the tubes in the extended configuration by interference or friction even without pressurized air in the mast. The locking device includes at least one safety device that can be deactivated only when the air in the mast reaches a preset pressure value to allow at least two tubes to move from the extended configuration to the retracted configuration.

[0008] In an embodiment, the safety device can be operated by the pressurized air in the telescopic mast.

[0009] In an embodiment, the locking device associated with the outer tube includes a latch supported by the outer tube and radially movable between an inactive retracted position and an active advanced position, in which the latch engages a latch seat obtained in at least one inner tube received in the outer tube.

[0010] In an embodiment, the movement of the latch is achieved by driving a manual control member operatively connected to the latch. The locking device includes a single-acting driver normally biased by an elastic element to prevent the drive control member and operable by pressurized air in the mast to disengage from the control member.

[0011] For example, the manual control member includes an eccentric pin integral with a control rod and engaging a slot of the latch, in which a locking hole is obtained that can engage a rod of the single-acting driver to lock the rotation of the eccentric pin.

[0012] In a variant, the movement of the latch is achieved by an actuating actuator operable using pressurized fluid to bring the latch from the active advanced position to the inactive retracted position.

[0013] In an embodiment, the actuating actuator is a pneumatic actuator operable by pressurized air in the mast.

[0014] In a variant, the mast includes a pressure switch adapted to detect the pressure value of the air in the mast, and the actuating actuator is operable through a drive circuit that supplies power to the actuating actuator when the pressure switch detects that a preset pressure value has been reached.

[0015] In an embodiment, the plurality of tubes of the mast includes a fixed base tube, and at least one locking device is supported by a locking ring fastened near the upper end of the fixed base tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In any case, with reference to the drawings, further features and advantages of the pneumatic telescopic mast according to the present invention will become apparent from the following description of its preferred embodiments, which are given only by way of non-limiting, illustrative examples, in the drawings:

[0017] Figure 1 and Figure 1a are two front views of a pneumatic telescopic mast in a retracted position according to an embodiment of the present invention;

[0018] Figure 2 is Figure 1 an enlarged view of detail A circled in

[0019] Figure 3 is Figure 1 an enlarged view of detail B circled in

[0020] Figure 4 is Figure 1a an enlarged view of detail C circled in

[0021] Figure 5 a front view of a partially extended mast;

[0022] Figure 6 an exploded perspective view of the locking ring of the mast in the previous figure;

[0023] Figure 7 is a perspective view of the assembled locking ring, where, in order to show the components of the locking ring, the ring structure is shown in a transparent manner;

[0024] Figure 8 is a top view of the locking ring;

[0025] Figures 9 to 12 and Figures 9a to 12a respectively show a plan view and a front view of the same number of locking rings in the same number of operating configurations;

[0026] Figure 13 is a pneumatic schematic diagram of a pneumatic telescopic mast;

[0027] Figure 14 is an exploded perspective view of the locking ring of a variant of the pneumatic telescopic mast;

[0028] Figure 15 is Figure 14 a top view of the locking ring in

[0029] Figure 16 and Figure 16a are two front views of the locking ring;

[0030] Figure 17 is an axial sectional view of the locking ring; and

[0031] Figure 18 and Figure 18a is Figures 14 to 17 a plan view and a sectional view of the electro-pneumatic control box of the pneumatic telescopic mast in

[0032] In the drawings, elements common to the various embodiments are denoted by the same reference numerals. Detailed Description

[0033] The numeral 1 generally denotes a pneumatic telescopic mast according to the invention, which is used, for example, for supporting and moving military communication equipment, lighting equipment and / or surveillance equipment. The mast 1 extends along a mast axis V-V and comprises a plurality of telescopically joined sealed tubes 2 and 2'. The tubes 2 and 2' are operable to switch from a retracted or compact mast configuration to an extended mast configuration and vice versa. The actuation of the tubes 2 and 2' is effected in a known manner by introducing pressurized air into the pneumatic telescopic mast 1.

[0034] The mast 1 is provided with tube locking means 3 which are adapted to lock the tube 2 in the extended configuration by interference or friction even when there is no pressurized air in the mast 1.

[0035] In an embodiment, each tube 2 and 2' is provided with tube locking means 3 which are operable to restrict and release a tube of slightly smaller diameter (hereinafter also defined as "inner tube", which, when the mast is in the compact state, is received in an outer tube which supports the locking means for restricting / releasing the inner tube). Thus, when the pneumatic telescopic mast is in the extended position, all the tube locking means 3 can be actuated so that each tube becomes integral with a tube of slightly smaller diameter. Thus, the pressurized air can be discharged from the mast without the need to bring the tubes back to the retracted position by gravity.

[0036] In certain embodiments, as shown in the depicted example, the tube locking means 3 consists of a radial latch 14 which is radially operable by translation between an advanced locking position and a retracted release position of a tube of slightly smaller diameter.

[0037] According to an aspect of the invention, the tube locking means 3 is operatively connected to at least one safety device 50 which is configured to keep the tube locking means 3 in the locked position and which can be deactivated only when the air in the mast 1 reaches a preset pressure value to allow the tube locking means 3 to switch to the release position.

[0038] Now referring Figures 1 to 13 , a pneumatic telescopic mast 1 according to the invention is described in a first embodiment.

[0039] The pneumatic telescopic mast 1 comprises a fixed lower tube 2' and a plurality of movable tubes 2. The fixed lower tube is provided, for example, with a plate 4 for anchoring to a support surface. The plurality of movable tubes 2 have a gradually decreasing diameter. The movable tube 2 having a diameter slightly smaller than that of the fixed lower tube 2' is also defined as the inner tube 2 or the first movable tube 2.

[0040] The fixed lower tube 2' is provided near its upper end with a locking ring 6 which is adapted to engage with the first movable tube 2 when the mast is in the state as Figure 1 and Figure 1aWhen in the compact position shown, the first movable tube is received within the fixed tube 2'.

[0041] This locking ring 6 includes an annular body 7 which is fastened, for example, by means of a plurality of fastening flat head screws 8 to the outer surface of the fixed lower tube 2'. The locking ring 6 is provided internally with an annular sealing element 10 and one or more guiding bands 12 which are suitable for facilitating the translation of the first movable tube 2 relative to the fixed lower tube 2'.

[0042] The locking ring 6 is provided with two radial locking latches 14 which are diametrically opposite to each other. Each latch 14 is slidably inserted into a latch seat 16 which is obtained in the annular body 7 of the locking ring 6. Each latch 14 is radially movable between an advanced locking position and a retracted or inactive release position of the first movable tube 2. When in the advanced locking position, the latch 14 projects radially from the inner wall of the locking ring 6 so as to engage with a corresponding latch recess obtained in the inner tube.

[0043] Each latch 14 is operatively translatable by means of a manual control lever 20 which is integral with an eccentric locking pin 22 which engages with a pin slot 24 obtained in the latch 14. Thus, the radial translation of the latch 14 corresponds to the rotation of the locking pin 22 about its pin axis (for example, parallel to the mast axis V-V).

[0044] In an embodiment, the locking pin 22 is received within a pin seat 26 which is obtained in the annular body 7 of the locking ring.

[0045] The latches 14, the locking pin 22 and the control lever 20 form a tube locking device 3.

[0046] The rotation of the locking pin 22 is controlled by a safety device 50 which includes a single-acting cylinder 52 which is at least partially received within a corresponding cylinder seat 54 which is obtained in the annular body 7 of the locking ring 6 and which is, for example, in communication with the pin seat 26. The single-acting cylinder 52 is provided with a rod 56 which is movable between an advanced locking position and a retracted release position. The cylinder 52 is normally urged by an elastic element (for example, a spring) which keeps the rod 56 in the advanced locking position. In this advanced locking position, the rod 56 engages with a radial hole 58 of the locking pin 22 preventing rotation from this locking position to the release position of the latch 14. The cylinder 52 can be supplied with pressurized air in order to bring the rod 56 to the retracted position, thus releasing the locking pin 22 and allowing the locking pin to rotate towards the release position and thus retract the latch 14.

[0047] In an embodiment, the single-acting cylinder 52 is supplied with pressurized air from a pneumatic telescopic mast 1. Thus, the rod 56 can be brought to the retracted position only when the air pressure in the mast 1 reaches a preset threshold value.

[0048] In the embodiment shown in the drawings, it is noted that the two cylinders 52 are supplied through a pneumatic circuit 60 which is in fluid communication with the interior of the telescopic mast 1.

[0049] For example, the pneumatic circuit 60 has an air inlet connection 62 which is connected to the mast 1 and a supply pipe 64 extends from this air inlet connection 62, the supply pipe rising from the base of the mast towards the locking ring 6 and bringing pressurized air to the two single-acting cylinders 52, for example through a distributor 66 which distributes the inlet air towards the two end pipes 68. The pneumatic circuit 60 may be provided with control means such as a pressure limiting device 70 and a pressure gauge 72.

[0050] Figure 9 and Figure 9a shows the locking ring 6 in the locking position of the inner tube 2, with the pressure of the air in the mast 1 being less than a preset value (for example, 1.3 bar). In this case, the rod 56 of the cylinder 52 is in the advanced locking position of the locking pin 22 and the control rod 20 cannot rotate to bring the latch 14 into the inactive retracted position. Thus, the inner tube 2 cannot move.

[0051] Figure 10 and Figure 10a shows the locking ring 6 in the locking position of the inner tube 2, given that the pressure of the air in the mast 1 is greater than a preset threshold value, while the rod 56 belonging to the cylinder 52 is in the inactive retracted position. Each control rod 20 remains in the locking position, but it can rotate in the Figure 10 direction of the arrow shown in

[0052] Figure 11 and Figure 11a shows the locking ring 6 in the release position of the inner tube 2. Here, the control rod 20 has rotated to the release position. Then, the latch 14 is brought to the retracted position. Since the rods 56 of the plurality of cylinders 52 are in the retracted position disengaged from the corresponding locking pins 22, each control rod 20 can rotate in both directions. Clearly, the control rod can only be brought back to the locking position when the latch 14 is located in the relevant recess of the inner tube 2. Thus, in this case, the inner tube can be raised or lowered.

[0053] Figure 12 and Figure 12a shows the locking ring 6 in an intermediate configuration, generally following Figure 11 and Figure 11aThe structure is such that the pressure inside the mast is lower than a preset threshold, but the control lever 20 is in the release position. In this case, the rod 56 advances partially under the action of the force of the elastic element that is not offset by the air pressure; the rod engages with the locking pin 22 but does not prevent the locking pin from rotating. When the latch recess of the inner tube 2 aligns with the corresponding latch 14, the latch can be translated to the advanced locking position, and each rod 56 of the cylinder 52 advances fully, thus locking the locking pin 22 in the locked position.

[0054] It is worth noting that in the case of an accidental disconnection of the pneumatic circuit of the airless or single-acting cylinder, this cylinder is brought into the locked position of the control lever, thus ensuring the safety of the mast.

[0055] As Figures 1 to 5 As can be noted, each movable tube 2 is provided with a locking ring 6, which is similar to the above-mentioned locking ring. In the example shown, only the locking ring 6 of the fixed lower tube 2' is provided with a safety device 50 that controls the rotation of the control lever. However, such a safety device can also be applied to one or more additional locking rings associated with the movable tubes.

[0056] Figure 13 Fig. shows a pneumatic schematic diagram of the telescopic mast 1, where it can be noted how the compressed air source 80 (e.g., a compressor) supplies the tubes of the mast 1 and the single-acting cylinders 52 in parallel.

[0057] Therefore, the operation of the mast is as follows.

[0058] Air is introduced into the mast itself to extend the mast. The operator releases the locking device of the mast, starting from the locking ring of the upper tube until reaching the lower tube associated with the locking ring of the fixed lower tube. Once a preset pressure (e.g., 1.3 + / - 0.15 bar) is reached, the single-acting cylinder releases the locking pin, allowing the control lever to bring the latch into the retracted position to extend the inner tube.

[0059] In the closing step of the mast, air will be introduced into the mast until the opening pressure of the single-acting cylinder (e.g., 1.3 bar) is reached. Once such a pressure value is reached, the rod of each cylinder is brought into the retracted position, thus allowing the corresponding control lever to release the latch. Then, the mast can be closed by gradually discharging air from the mast.

[0060] Figures 14 to 18 Fig. shows a variant locking ring 600.

[0061] The overall structure of this locking ring 600 is similar to the overall structure of the above-mentioned ring 6, but the mode of implementing the safety device 650 is different from it.

[0062] As in the previous case, the locking ring 600 is provided with two diametrically opposed radial latches 14 which are movable between a forward locking position and a retracted release position, where, in the forward locking position, the latches engage corresponding latch recesses obtained in the first movable tube and, in the retracted release position, the latches disengage from these recesses, thus allowing the first movable tube 2 to translate.

[0063] In this embodiment, each latch 14 is directly moved by a single-acting cylinder 652 which can be supplied with pressurized fluid.

[0064] In the preferred embodiment shown in the drawings, the single-acting cylinder 652 has a rod 656 which is, for example, connected to the corresponding latch 14 by means of a thread.

[0065] Thus, the pressurized fluid can be the same air supplied to the telescopic mast or, in an alternative embodiment, the pressurized fluid can be a fluid from another supply circuit of the cylinder.

[0066] In any case, when the pressure of the control fluid exceeds a preset threshold, the single-acting cylinder 652 overcomes the force of the elastic element 657 and controls the retraction of the latch 14.

[0067] In the embodiment, the latch 14 and the cylinder 652 are supported by a support plate 660 which is anchored to the annular body 607 of the locking ring 600.

[0068] As in the previous embodiment, two diametrically opposed cylinders 652 are supplied in parallel by a pneumatic circuit 60 which includes a distributor 66 which receives pressurized air from a compressed air source and distributes an air flow to the two cylinders 652 through end tubes 68.

[0069] The elastic element 657 can be a spring which is housed in the cylinder or, as Figure 14 shown in the example, the elastic element can consist of a pair of compression springs which are inserted between the latch 14 and the support plate 660 and which tend to keep the latch in the forward locking position. When the cylinder 652 is supplied with a control fluid having a pressure equal to or greater than the preset threshold, the rod 656 is controlled to retract against the force of the elastic element, thus moving the latch 14 into the retracted release position.

[0070] In the embodiment, the telescopic mast 1 includes an electro-pneumatic control box 100 which includes all the elements required to control the opening and closing of the mast 1.

[0071] Specifically, in the control box 100, there are a first solenoid valve 112 and a second solenoid valve 114. The first solenoid valve is used to control the addition of compressed air to the mast 1 and the discharge of compressed air from the mast 1. The second solenoid valve is used to control the opening and closing of the single-acting cylinders 52 and 652, and the single-acting cylinders implement the safety device.

[0072] The control box 100 further includes a first pressure switch 118a and a second pressure switch 118b. The first pressure switch is suitable for checking the presence of network pressure, and the second pressure switch is suitable for detecting the pressure in the chamber of the mast.

[0073] However, this second pressure switch can also be alternatively directly mounted at the base of the mast.

[0074] The control box 100 can also include a pneumatic circuit 120. The pneumatic circuit includes, for example, a manually operable valve. If the electrical control cannot be used due to damage to the power supply or lack of power supply, the pneumatic circuit can allow the mast to retract safely.

[0075] The opening of the mast 1 is achieved by separately supplying pressurized air into the mast. The closing is achieved by driving the latch on the locking ring through a logic function. In the case of the mast being open, only when the latch retracts, if there is sufficient internal pressure to keep the mast balanced under the action of the earth's gravity, the logic function will provide permission to open the latch.

[0076] In an embodiment, the pneumatic telescopic mast 1 is further provided with a remote control device 200. The remote control device serves as a human-machine interface and is operably connected to the control box 100.

[0077] The remote control device 200 includes an electronic control board, which is the electronic control board for the solenoid valves 112 and 114 in the electro-pneumatic control box 100. The electronic board implements this logic, which is defined by the inputs provided by the pressure switches 118a and 118b, defined by the proximity sensor on the actuator of the locking ring, and defined by the limit switch on the ring itself.

[0078] As Figure 19 shown, the remote control device 200 is provided with buttons 202a and 202b, a light-signal device 204, a selector 206, a pressure gauge 208, a first electrical connector 210, and an optional second connector 212. Among them, the buttons are used to control the raising and lowering of the mast, the selector is used to select the operation mode of the mast (automatic, manual, control off), the pressure gauge indicates the air pressure in the mast 1, the first electrical connector is used to communicate with the control box 100, and the second connector implements a protocol communication port.

[0079] As described above, once extended, the pneumatic telescopic mast can remain open indefinitely. The mast can remain in such a configuration even without the entire control system.

[0080] In an embodiment, the operation of the telescopic mast during the lowering (i.e., closing) step provides the following actions.

[0081] The operator turns the electro-pneumatic remote controller 200 to the automatic mode or the manual mode and presses the lowering button 202b.

[0082] If the pressure switch 118b detects sufficient pressurized air in the mast, the mast lowers. In the automatic mode, the button can be released. In the manual mode, the button remains pressed.

[0083] Since the safety device is still actuated, the mast does not lower if the air in the mast is not sufficiently pressurized. In this case, one of the optical signal devices 204 near the pressure gauge 208 turns red.

[0084] The operator can press the raising button 202a to fill the mast with air until a minimum preset pressure is reached. For example, the signal device near the raising button can flash to advise the operator to perform this action.

[0085] When the mast has reached the preset pressure (which can be signaled by lighting the signal device), the safety device is deactivated and, by pressing the lowering button 202b again, the mast starts to discharge air, thus allowing the lowering step.

[0086] In another embodiment, a pressure sensor can be used, which checks the pressure level of the air in the mast. For example, the pressure sensor can allow or deny the release of the locking device through suitable control logic.

[0087] The sensor, logic port, and locking device can be manufactured using pneumatic devices, electric devices, hydraulic devices, mechanical devices, or a combination of these technologies.

[0088] The described safety system can also include a human-machine interface that displays the pressure status in the mast to the operator to advise the operator of the operation to be performed.

[0089] In all embodiments, if the mast is not pre-pressurized to a preset level, the locking device (e.g., latch) of the mast cannot be deactivated when the mast extends.

[0090] Thus, it is obvious how the described pneumatic telescopic mast can achieve the purpose of preventing the accidental deactivation of the locking device when there is not enough pressure in the mast to keep the tube in the extended position.

[0091] Those skilled in the art can make various changes and adjustments to the above embodiments of the pneumatic telescopic mast according to the present invention without departing from the scope of protection of the following claims, and can replace these elements with other functionally equivalent elements to meet possible needs. Each feature described as belonging to a possible embodiment can be implemented without considering the other described embodiments.

Claims

1. A pneumatic telescopic mast, the pneumatic telescopic mast comprising a plurality of telescopically coupled sealed tubes operable to switch from a retracted configuration to an extended configuration and from the extended configuration to the retracted configuration, wherein, The drive of the tube is achieved by introducing pressurized air into the pneumatic telescopic mast. Even when there is no pressurized air in the mast, the tube locking device is adapted to lock the tube in the extended configuration by interference or friction. Wherein, the tube locking device includes at least one safety device, the at least one safety device is configured to keep the tube locking device in the locked position, and only when the air in the mast reaches a preset pressure value, the at least one safety device can be deactivated to allow the tube locking device to switch to the release position. The mast is characterized in that the safety device can be operated by the pressurized air in the telescopic mast.

2. The pneumatic telescopic mast according to claim 1, wherein, The pneumatic telescopic mast is used to support and move military communication equipment, lighting equipment and / or surveillance equipment.

3. The pneumatic telescopic mast according to claim 1 or 2, wherein, The tube locking device includes at least one latch, the at least one latch can move radially between an inactive retracted position and an active advanced position. Wherein, the latch engages with a latch recess obtained in one of the plurality of telescopically coupled sealed tubes, and the diameter of the tube in which the latch recess is obtained is smaller than the diameter of the tube supporting the latch.

4. The pneumatic telescopic mast according to claim 3, wherein, The movement of the latch is achieved by driving a manual control member, the manual control member is operatively connected to the latch, and wherein, the safety device includes a single-acting cylinder, the single-acting cylinder is biased by at least one elastic element to prevent driving the manual control member, and can be operated by the pressurized air in the mast to disengage from the manual control member.

5. The pneumatic telescopic mast according to claim 4, wherein The manual control member includes an eccentric locking pin, the eccentric locking pin is integral with a control rod and engages with a slot of the latch. A locking hole is obtained on the eccentric locking pin, and the locking hole can engage with the rod of the single-acting cylinder to lock the rotation of the eccentric locking pin.

6. The pneumatic telescopic mast according to claim 3, wherein, The movement of the latch is achieved by a single-acting cylinder, the single-acting cylinder can be operated using pressurized fluid to bring the latch from the active advanced position to the inactive retracted position.

7. The pneumatic telescopic mast according to claim 6, wherein The single-acting cylinder can be operated by the pressurized air in the mast.

8. The pneumatic telescopic mast according to claim 6, comprising a pressure switch, the pressure switch is adapted to detect the pressure value of the air in the mast, the single-acting cylinder can be operated through a drive circuit, and when the pressure switch detects that the preset pressure value is reached, the drive circuit provides power for the single-acting cylinder.

9. The pneumatic telescopic mast according to claim 1, wherein, The plurality of telescopically coupled sealed tubes includes a fixed base tube, and at least one safety device is supported by a locking ring, the locking ring is fastened near the upper end of the fixed base tube.

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