Hydraulic actuator for swing gates or overhead doors with pressure switch

Abstract

 Hydraulic actuator for swing gates or overhead doors that comprises an electric motor (2), a hydraulic pump (3) and a hydraulic distributor (4) that distributes a fluid originated from the hydraulic pump (3) to a hydraulic cylinder (5). Said hydraulic cylinder (5) comprises two chambers (27,28) separated by a piston (8) which is displaced in its interior by the action of said fluid, causing the movement of the door. The hydraulic actuator comprises a detection means (30) that detects variations in the pressure of the fluid comprised in one of the chambers (27,28) over a rating pressure or below a normal operating pressure, including said detection means (30), an electric switch (9) and an actuating means (31) that switches said electric switch (9) on or off.

Description

TECHNICAL FIELD

[0001] The present invention relates to a hydraulic actuator for swing gates or overhead doors.

PRIOR ART

[0002] At present, hydraulic units are frequently used for the operating of overhead doors such as that described, for example, in ES 8100441 A1, which comprises an electric motor, a hydraulic pump powered by said electric motor and a hydraulic distributor that distributes a fluid driven by the pump towards a hydraulic cylinder, said hydraulic cylinder comprising a piston that is displaced by the pressure exerted by the fluid, causing the movement of a rod that acts directly on the door.

[0003] ES 2024105 A6 describes a hydraulic unit for the operating of swing gates that comprises a pump, a distributor, a hydraulic cylinder with a piston that is displaced by the pressure exerted by the fluid, and a drive mechanism of the rack and pinion type that turns the linear movement of the piston into a rotational movement of an shaft connected to an arm which acts directly on the door.

[0004] Said hydraulic units or actuators, in the event that the door traps an obstacle during its opening or closing stroke, continue to push the door against said obstacle exerting a pressure that depends on the predetermined rating pressure until the operating time of the hydraulic actuator ends.

DISCLOSURE OF THE INVENTION

[0005] The objective of this invention is to provide a hydraulic actuator for overhead doors or swing gates as defined in the claims.

[0006] It is an object of this invention to provide a hydraulic actuator for overhead doors or swing gates that, in the event of encountering an obstacle during the opening or closing stroke of the door, detects the presence of said obstacle so that it is possible to remove the trapped obstacle quickly. To achieve this, the hydraulic actuator incorporates a means for detecting either an increase in the pressure of the fluid above a predetermined rating pressure or, rather, a reduction in the pressure of the fluid below a normal operating pressure, as both situations occur when the door traps an obstacle.

[0007] The inventive hydraulic actuator is made up of a motor that powers a hydraulic pump and a hydraulic distributor that distributes a fluid driven by the hydraulic pump towards a hydraulic cylinder, in whose interior a piston is displaced by the action of the fluid originating from the hydraulic distributor. The means for detecting said variations of pressure is generally included in the hydraulic distributor, although it may be connected to another integral element of the hydraulic actuator. Said detection means comprises an electric switch and an actuating means which switches said switch on or off when it receives or stops receiving pressure. The change in the switch condition is interpreted by a control as an obstacle encountered by the door during its stroke, as a result of which it sends to the hydraulic actuator an instruction to modify its operation.

DESCRIPTION OF THE DRAWINGS

[0008] 

Fig.1 is a joint view of a first embodiment of the invention.

Fig.2 is a front view of the hydraulic distributor shown in Fig.1.

Fig.3 is a sectional view of the hydraulic distributor shown in Fig.1 with the doors in a closed position.

Fig.4 is a sectional view of the hydraulic distributor shown in Fig.3 in the event of the door encountering an obstacle during its closing stroke.

Fig.5 is a sectional view of the hydraulic distributor shown in Fig.1 with the doors in an open position.

Fig.6 is a sectional view of the hydraulic distributor shown in Fig.5 in the event of the door encountering an obstacle during its opening stroke.

Fig.7 is a sectional view of the hydraulic distributor in accordance with the second embodiment of the invention, in the event of the door encountering an obstacle during its opening stroke.

Fig.8 is a sectional view of the hydraulic distributor shown in Fig.7 in the event of the door encountering an obstacle during its closing stroke.

DETAILED DISCLOSURE OF THE INVENTION

[0009] Fig.1 shows a hydraulic actuator 1 for overhead doors that comprises a hydraulic pump 3 powered by an electric motor 2, a hydraulic distributor 4 that distributes the fluid driven by the hydraulic pump 3, a hydraulic cylinder 5 in whose interior is displaced a double effect piston 8 driven by the fluid originating from the distributor 4 and a cap 7 of the hydraulic cylinder 5, said hydraulic actuator 1 acting on the overhead door, through a drive mechanism, that may be of the linear type such as a rod 8b, built into the piston 8, that passes through the cap 7 being fixed to the door by a fastening means, or for example, of the rack and pinion type, not included in the figures, which is powered by the piston 8 converting the axial displacement of the piston 8 into a rotational movement of the door shaft.

[0010] The hydraulic cylinder 5 comprises a pair of chambers separated by the piston 8, where a first chamber 27 is limited by the piston 8 and the hydraulic distributor 4, and a second chamber 28 is limited by the piston 8 and the cap 7, said second chamber 28 being connected to the hydraulic distributor 4 by an external return conduit 15.

[0011] Figs. 2-8 show the hydraulic distributor 4, which includes a slide 6 fitted into a housing 12 throughout which it is displaced, driven by the fluid originated from the hydraulic pump 3 through a first impulsion conduit 20 and a second impulsion conduit 21. The slide 6 delimits in the housing 12, a first cavity 50 connected to the first impulsion conduit 20, a second cavity 51 connected to the second impulsion conduit 21 and an intermediate cavity 52 positioned between both cavities 50,51.

[0012] The hydraulic distributor 4 comprises a primary regulation valve 25 and a secondary regulation valve 26, both set at a specific rating pressure, and which are housed respectively in a first cavity 10 and a second cavity 11 of the hydraulic distributor 4, both cavities 10,11 being connected to the housing 12, respectively, by a primary connection conduit 13 and a secondary connection conduit 14.

[0013] The hydraulic distributor 4 is connected to the first chamber 27 by a primary distribution conduit 24, and to the return conduit 15, connected to the second chamber 28 by a secondary distribution conduit 29, which at the same time, is connected to the housing 12 by the secondary connection conduit 14 of the secondary regulation valve 26.

[0014] The primary regulation valve 25 is connected to the secondary regulation valve 26 by an intermediate conduit 18 and each regulation valve 25,26 comprises respectively a top 40,41, a spring 42,43 and a screw 44,45 with which the predetermined rating pressure is regulated.

[0015] In a first embodiment of the invention, shown in Figs. 3-6, the hydraulic distributor 4 incorporates a means 30 for detecting pressures over the rating pressures of the regulating valves 25,26, which comprises an electric switch 9 fixed to one of the side walls 34 of said hydraulic distributor 4 and with a contact member 9b oriented towards the interior of said hydraulic distributor 4, a derivation conduit 33 connected directly to the cavity 10 and an actuating means 31, such as a ball, that operates said contact member 9b, said ball being housed and guided in a cylindrical cavity 32 positioned between the derivation conduit 33 and the electric switch 9.

[0016] Fig. 3 shows the hydraulic distributor 4 comprised in the hydraulic actuator 1 in the door closing condition, during which time the motor 2 powers the hydraulic pump 3 driving the fluid through a first impulsion conduit 20 of the hydraulic distributor 4, so that the slide 6 is displaced in the housing 12 to the left, according to Fig. 3, enabling the passage of fluid to the first chamber 27 through the primary distribution conduit 24 and closing the passage of said fluid towards the secondary distribution conduit 29. The piston 8 is displaced due to the pressure exerted by the fluid in the first chamber 27, towards its end of stroke where the door is completely closed. During this displacement, the fluid comprised in the second chamber 28 is evacuated towards the hydraulic distributor 4 through the return conduit 15 towards the intermediate chamber 52 of the housing 12, being sucked by the hydraulic pump 3.

[0017] Fig.4 shows the hydraulic distributor 4 in a situation in which the door encounters an obstacle during its closing stroke. When the door traps the object, the motor 2 continues to operate, driving fluid through the first impulsion conduit 20 without the piston 8 being displaced, as a result of which the pressure of the fluid in the hydraulic distributor 4 and the first chamber 27 increases until the rating pressure of the primary regulation valve 25 is exceeded. At this point, the primary top 40 of said regulation valve 25 is displaced against the primary spring 42, enabling the passage of fluid towards the derivation conduit 33. The pressure of said fluid displaces the ball 31 towards the contact member of the switch 9b activating it, so that it sends a signal to a control panel, not shown, so that the motor 2 give the command to reverse the operation.

[0018] Fig.5 shows the hydraulic distributor 4 in the door opening condition, in which condition the motor 2 powers the hydraulic pump 3 in an anti-clockwise direction, driving the fluid through the second impulsion conduit 21, which displaces the slide 6 in the housing 12 towards the right side, according to Fig. 5, so that it enables the passage of fluid to the second chamber 28 through the secondary distribution chamber 29 and the return conduit 15 and closes the passage of said fluid towards the primary distribution conduit 24. The piston 8 is displaced, by the effect of the pressure exerted in the second chamber 28, towards the hydraulic distributor 4 until its end of stroke, where the door is completely open. During this displacement of the piston 8, the fluid comprised in the first chamber 27 flows, through the primary distribution conduit 24 towards the intermediate chamber 52 of the housing 12, it being sucked by the hydraulic pump 3.

[0019] Fig.6 shows the hydraulic distributor 4 in a situation in which the door encounters an obstacle in its closing stroke. When the door traps the object during its opening stroke, it continues to drive fluid through the secondary distribution conduit 29 towards the second chamber 28, without the piston 8 being displaced, as a result of which the pressure of the fluid in the hydraulic distributor 4 and the second chamber 28 increases until the rating pressure of the secondary regulation valve 26 is exceeded. At this point, the secondary top 41 is displaced against the secondary spring 43, enabling the passage of fluid towards the derivation conduit 33, through the intermediate conduit 18. The pressure of said fluid displaces the ball 31 towards the contact member of the switch 9b activating it, so that it sends a signal to a control panel, not shown in the figures, to act as programmed.

[0020] In a second embodiment of the invention, shown in Figs.7-8, the detection means 30 detects pressures below a normal operating pressure of the fluid comprised in the derivation conduit 33, which is connected directly to the intermediate cavity 52 of the housing 12. The electric switch 9, at the same time, is fixed onto a base of the hydraulic distributor 4 opposite the base where the regulation valves 25,26 are housed and the actuating means 31 is positioned between the derivation conduit 33 and said electric switch 9. In the event that the door traps the object in its closing stroke (see Fig.7), the pressure of the fluid in the second chamber 28 falls below the normal operating pressure, and in contrast, when the door traps the object in its opening stroke (see Fig.8) it is the pressure of the fluid in the first chamber 27 that falls below the normal operating pressure. In both cases, the pressure of the fluid housed in the derivation conduit 33 falls, causing the ball 31 to be displaced, moving away from the contact member of the switch 9b and deactivating said switch 9, so that it sends a signal to the control panel, not shown in the figures, to act as programmed.

Claims

1. Hydraulic actuator for swing gates or overhead doors that comprises

• an electric motor (2),

• a hydraulic pump (3) powered by the electric motor (2),

• a hydraulic distributor (4) that distributes a fluid originating from the hydraulic pump (3) to a hydraulic cylinder (5), said hydraulic cylinder (5) comprising two chambers (27,28) separated by a piston (8) that is displaced in its interior by the action of said fluid, causing the movement of the swing or pivoted door,

characterised in that the hydraulic actuator comprises a detection means (30) that detects an increase in pressure over a rating pressure or a decrease in pressure below a normal operating pressure, of the pressure of the fluid comprised in one of the chambers (27,28), including said detection means (30), an electric switch (9) and an actuating means (31) that switches said electric switch (9) on or off when said respective increase or decrease in the pressure of the fluid occurs.

2. Hydraulic actuator for swing gates or overhead doors according to claim 1, comprising a derivation conduit (33) that enables the passage of fluid towards the actuating means (31), said derivation conduit (33) being connected to a housing (12) of the hydraulic distributor (4) along which a slide (6) is displaced driven by the fluid originating from the hydraulic conduit (3), said slide (6) delimiting in the housing (12) at least a pair of cavities (50,51).

3. Hydraulic actuator for swing gates or overhead doors according to claim 2, wherein the hydraulic distributor (4) comprises regulation valves (25,26) set so that they open at the rating pressure of the fluid, and which are housed in cavities (10,11) of the hydraulic distributor (4), being connected to each other through an intermediate conduit (18) and at the same time connected to the housing (12), and the derivation conduit (33) is connected directly to one of said cavities (10,11), said derivation conduit (33) enabling the passage of a fluid whose pressure is higher than the rating pressure of the regulation valves (25,26) towards the actuating means (31), which switches on the electric switch (9), said electric switch (9) being fixed to said hydraulic distributor (4).

4. Hydraulic actuator for swing gates or overhead doors according to claim 2, wherein the derivation conduit (33) is directly connected to an intermediate cavity (52) delimited by the slide (6) in the housing (12), so that when the pressure of fluid housed in said derivation conduit (33) falls below a predetermined normal operating pressure, the actuating means (31) switches off the switch (9).

5. Hydraulic actuator for swing gates or overhead doors according to any of the preceding claims, wherein the actuating means (31) comprises a ball, guided in a cavity (32), where it is displaced longitudinally by the effect of the pressure of the fluid switching the switch (9) on or off, said cavity (32) being positioned between the derivation conduit (33) and the switch (9).

6. Hydraulic actuator for swing gates or overhead doors according to claim 5, wherein the ball (31) has a greater diameter than the derivation conduit (33).

Drawing