This invention relates to an actuator device for use in the control of gates or similar barriers.

Reference is made to Applicants co-pending Australian Application Nos. PI7203/88 and PI9645/88 and to PCT Applications based thereon and the whole subject matter of the Specifications thereof is to be considered to be imported hereinto.

An object of the present invention is to provide an improved actuator device which is relatively simple in construction and easy to install. The many advantages of the actuator device of the present invention over prior art devices will become readily apparent to those persons skilled in the art from a reading of the following description.

n

Basically in accordance with the present invention there is provided an actuator device which is suitable for the control and operation of a gate or barrier, the actuator device comprising an hydraulic ram assembly which includes a cylinder having a piston therein, the piston separating the cylinder into two chambers. One part (i.e. either the piston or the cylinder) of the hydraulic ram assembly is operatively connected to the gate or barrier, and the other part is operatively connected to a fixture or like support such as a gate post. The arrangement is such that relative movement between the piston and the cylinder causes movement of the gate or barrier between for example", open and closed positions .

The actuator device further includes" means for delivering and discharging operating fluid to and from each container to cause the relative movement between the piston and cylinder, and thereby in turn move the gate or barrier. The operating fluid may be any suitable hydraulic fluid, however, in a preferred embodiment of the invention the operating fluid used is water.

The actuator device may further include valve means operable so as to selectively control the delivery and discharge of operating fluid to and from the chambers within the cylinder . In a preferred form of the invention, two valves are provided each valve controlling the delivery and discharge of the operating fluid to and from a respective one of the chambers within the cylinder . Each valve is capable of adopting a first position in which the operating fluid under pressure can be delivered to its associated chamber , and a second position in which f luid can be discharged from the associated chamber . In a further preferred form of the invention the valves may be capable of adopting a third position in which fluid is prevented from discharge from the chamber . In this particular arrangement, an hydraulic lock is formed thereby inhibiting

1 movement of the gate or barrier with the valve in this third

2 position. The two valves are preferably arranged such that

3 when one adopts its first position, the other adopts its

4 second position and vice versa. 5

6 Preferably a feed line is provided for delivering and

7 discharging hydraulic operating fluid to each chamber.

8 Preferably the valves are disposed within the respective

9 feed lines there being an input branch for delivering the

10 operating fluid from a source or reservoir and a discharge

11 branch for discharging the operating fluid to a drain for 12. example.

13

14 Preferably the valves are in the form of solenoid

15 valves and control means is provided to cause selective _.

16 operation of those valves. The solenoid valves are adapted

17 to open and close on request per an electric pulse or with a

18 time delay close cycle. 19

20 The actuator may be controlled by a radi transmitter

21 and receiver or similar switch means capable of operating

22 for example a bi-stable relay which in turn operates the two

23 solenoid valves. Thus, by pulsing the circuit, the 4 selective operation of the valves can effected. A tuner may 5 be provided to automatically shut down the circuit after a 6 preselected period. 7 8 In one particular embodiment means is provided for 9 collection of discharged operating fluid and means is 0 provided for pressurizing the discharged operating fluid for 1 use as delivery operating fluid. As indicated, a pump may 2 be provided to effect such pressurizing. 3 4 Preferably, storage means is provided for storage of 5 pressurized delivery operating fluid and that means 6 preferably has a volumetric capacity at least equal to that 7 required for one, preferably two and more preferably three, 8 openings or closings of the gate or barrier so as to enable

an opening or closing notwithstanding failure of the pump or other means for pressurizing and/or to enable a low capacity pump to be used.

In this last respect, in many situations the time period between a user wishing to open or close the gate or barrier for a first and then a second time will be substantial and thus it becomes practical to use a low cost pump of low capacity which, of itself, would not effect opening or closing in a satisfactory time but when coupled with such storage means it should be possible to effect opening or closing in an acceptable time. Thus, the pump may have a pumping capacity in litres pumped in one minute which may be half or less than the number of litres of operating fluid which is required to be delivered to the ram assembly to effect an opening or closing.

Pumps of such low capacity are available commercially and are inexpensive.

Further, such low capacity pumps have low current draw requirements and are often operable by storage batteries and thus mains electric power and the hazards associated with it may be avoided except for battery charging.

Further, it is also practicable to use solar cells for charging purposes and thus the need for mains electric power can be totally avoided if desired.

In another aspect, the present invention provides apparatus for providing a source of operating fluid for such an actuator device comprising a vessel adapted to contain a fluid, means adapted to apply pressure to that fluid in consequence of a vehicle passing over an area, and means for connecting resultant fluid pressure to said device.

The vessel may be provided with a flexible wall which can be flexed by being driven over by a vehicle.

Alternatively, a mechanism may be provided for transmitting load of a vehicle into fluid to pressurize the fluid.

In this instance a reservoir for fluid under pressure may be provided and which can also be provided with a valve to enable manual operation.

In order to enable a clearer understanding of the invention drawings illustrating exemplary embodiments are attached, and in those drawings:

Figure 1 is a schematic plan view of an actuator device according to the present invention with a gate in a first position;

Figure 2 is a similar view to that of figure 1 with the gate in a second position;

Figure 3 is a schematic view of a self-contained source of pressurized hydraulic fluid; and

Figure 4 is a schematic view of another source of pressurized hydraulic fluid.

Referring to the drawings, the actuator device generally indicated at 1 is operatively connected to a gate 20 which is swingable on gate post 21. The actuator device comprises an hydraulic double acting hydraulic ram 3 comprising a piston 4 and cylinder 5 the piston separating the cylinder into two chambers 13 and 14. One end of the cylinder 5 is connected to the gate post and the piston rod is connected to the gate.

A delivery discharge line 12 enables hydraulic fluid to be delivered and discharged to the respective chambers. An input line 11 having an inlet 21 feeds hydraulic fluid from a pressurized source via solenoid valves 8 to the

1 delivery/discharge lines 12. An output line 10 enables the

2 hydraulic fluid to be discharged through the valve 8 to an

3 outlet 22 or the like. 4

5 The self-contained source of pressurized hydraulic

6 fluid shown in Figure 3 comprises a fluid inlet 31 which is

7 intended to be connected to the outlet 22 in Figure 1, a

8 sump 32 for collection of hydraulic fluid passed via the

9 outlet 22 and the inlet 31, a pump 33 for drawing fluid from

10 the sump 32 and for pressurizing the fluid, a line 34 having

11 a one way valve 36, a storage vessel 37 and a line 38 having

12 an outlet 39 for connection to the inlet 21 shown in Figure

13 1.

I ⁴

15 The pump 33 is supplied by a storage battery 41 which

16 is chargeable by a solar cell array 42. 17

18 The storage vessel 37 (which is shown schematically in

19 cross-section) has an air pocket 43, above hydraulic fluid

20 44. The air in the pocket 43 will _. be compressed. The

21 storage vessel 37 has a capacity for hydraulic fluid at

22 least equal to the amount of hydraulic fluid required to

23 once operate the ram 3 in the gate opening or closing

24 direction. " 25

26 The pump 33 has a pumping capacity of less than half

27 in litres/minute the number of litres required to once

28 operate the ram 3 in the opening or closing direction.

29 However, this last is economical both as to the size and the

30 cost of the pump and is unlikely to be a problem because of

31 the capacity of the storage vessel 37 and because the

32 compressed air in the air pocket 43 will be able to effect

33 opening or closing of the gate. 34

35 In Figure 4 is shown a flexible walled vessel 51, a

36 fluid inlet 31 which is intended to be connected to the

37 outlet 22 in Figure 1 and which is connected via an inlet

38 line 52 and a one-way valve 53 to the vessel 51.

An outlet line 54 to the vessel is provided and passes via a one-way, valve 56 to an outlet 39 for connection to the inlet 21 in Figure 1.

A line 57 provided with a one-way valve 58 but which is manually releasable leads to a reservoir 59.

In use, a vehicle wheel 59 passing over the vessel 51 will cause fluid in the vessel to pass via line 54 and valve 56 to the outlet 39 for operation of the device shown in Figure 1.

_. Return fluid from outlet 22 will return to the vessel 51 .

Excess fluid can pass to the reservoir 59 from whence it may be manually released to operate the device shown in Figure 1 by manual operation of valve 58.

^" Finally , it is to be understood that the inventive concept in any of its aspects can be incorporated in many di f ferent constructions so that the general ity of the preceding description i s not to be superseded by the parti cul arity o f the attached drawings . Various alterat ions , modi f ications and or additions may be incorporated into the various constructions and arrangements of parts without departing from the spirit and ambit of the invention .