US2606761A - Hydraulic door actuator - Google Patents

Description

g- 12, 1952 c. G. G. GROUP 2,606,761

HYDRAULIC DOOR ACTUATOR Filed June 29, 1949 4 Sheets-Sheet l INVENTOR. CHARLES 6'. 6. GROUP A g- 1952 c. G. G. GR OUP HYDRAULIC DOOR ACTUATOR 4 Sheets-Sheet 2 Filed June 29, 1949 FIG. 3

FIG/4 INVENTOR. CHARLES G. 6. GROUP g- 12, 1952 c. G. G. GROUP 2,606,761

HYDRAULIC DOOR ACTUATOR Filed June 29, 1949 4 Sheets-Sheet 3 INVENTOR.

CHARLES 6. 6. GROUP Qaz 12, 1952 c. G. G. GROUP HYDRAULIC. DOOR ACTUATOR Filed June 29, 1949 4 Sheets-Sheet 4 FIG. 7

' INVENTOR. CHARLES G 6'. GROUP FIG. 8

Patented Aug. 12, 1952 UNITED; STATES PATENT -.o FF.IcEif-f .Charles G. G. Group, Cleveland, Ohio Application June 29, 1949, Serial Nc.102, 70; I

This invention relates "to door openers and more particularly to a door opener hydraulically operated by a weight on a platform.

The desirability for an'automatic door opener has long been present. Among the first attempts to fill this need is .thegate which opens upon pulling a rope on the end of a long lever.

Since that time, many more attempts have been made with more or less success.

These attempts include those openers which require electronic circuits for their action. These may be set off either by sound, as from a tuned horn or by the interruption of a light beam focused on a photoelectric cell. These, however, require an electronic relay and a motor and are, therefore, somewhat expensive and are subject to tube failures andthe like in the relay.

Other attempts have been based on hydraulic mechanism. In order to obtain pressure for these systems, it was common to use the pressure of city water or that supplied by a separate pump. This gave an adequate supply of fluid to operate the actuator piston through its relatively 1 Claim. (Cl. 26837) long required stroke. In general, however, these required the manual turning of a valve which was mounted on a post beside the driveway, requiring that the automobile be run sufliciently close to that valve to reach it, or that the driver disembark which is the maneuver sought to be avoided.

Theprincipal reason for the lack of a simple door opener operated by the weight of the vehicle approaching the door has been the fact that a long stroke is required .of the operating piston, and this piston must be of suificient area to supply force enough to startthe opening of the door even when it sticks somewhat. This requires a fairly large quantity of oil or other hydraulic fluid, and in order to obtain this volume, the pressure generating cylinder must be sufiiciently large to deliver the full quantity. However, this leads to a severe problem. The volume must'be obtained either by lengthening the stroke or increasing the diameter. Lengthening the stroke, in general, leads to a situation where the car must be tilted uncomfortably to operate the device; Increasing the piston diameter on the other hand decreases the available pressure for a given weight to the point where the force of the actuator piston may be insufficient to over- 4 the a highstarting pressure and after the door is 4 2 started opening, sufiicient volume ofifluid issueplied at a lower pressure'to continue theopening of the door. 1 1 A more complete" understanding of my invention, and the invention its'elf, may be had from reference to the accompanying figures'in'which: Fig.1 is a view partlyrin section-showing-the actuator of my invention; r A V Fig. 2 is a front view of'the pressure supply mechanism of my invention'showing theipre's surecylinders in section;

Fig. 3 is a side View of the pressure sup'ply s'y's tem;

Fig. 4 is a side view of an alternative einbo'di ment of my pressure supply system;

Fig. 5 is a sectional view'showi'ng anotheralternative form of the pressure supply system of my invention; v

Fig. 6 is a view similar'to" Fig."5' Sh'0Win'g'ls'ti11 another alternative form of the-pressure supply system of my invention;

Fig. 7 is a view showing my "inventionasfa'p plied to one type of gate;

Fig. 8 is a sectional viewr'sho'wing my inven, tion as applied to a tilting door; and

Fig. 9 is a section view from above "the door showingthe mounting means.

Briefly, my invention comprisesaniactuating cylinder which may be adapted to operate any'of several well knowntypes'of doors. Inthe main; these doors are cable operated, and therefore I have shown the device as adapted to wind :9.

cable on a drum. It will be apparent, however, that my invention need not'be so limited; The fluid under pressure for this cylinder is supplied from a plurality of pressure cylinders. the simplest form, there are two cylinders engaged by a" platform over which the vehicle is driven. These would be arranged so'tha't "the platform would engage one some time before engaging the other. Since the full weight on the wheel then on the platform is first'applied to a single piston, the pressure will be quite great at first; the platform engages the second'piston, since the eight. will then be. divided between the two. i. e., over twice the piston area if the pistons "are of equal size, the pressure then is halved. How'- ever, since the door has already been started by the high pressure, less pressure is required to continue the opening processand the required volume is obtained by the use of the two cylinders. Several variations of this device areshown in the figures and more fully described below. The actuator cylinder of my device is best shown in Fig. 1 with its mounting and'the-driim for connection to cable operated gates or doors. The cylinder II is mounted on a plate l2 which is adapted to be fastened to the wall of the building 'or gate post. A cable l3 extends from the rod ll of the piston 15 around a pulley it also pivotally mounted on the plate [2. This pulley carries a drum l1 preferably of larger diameter than the pulley, on which the operating cables l8of the door may be wound. From the pulley [6 the cable 13 passes to a point where it is fastened to a spring I9 adapted to keep tension in the cable and to return the piston IE to its top position in the cylinder II when the fluid pressure is released.

A simple valve system may be used in this cylinder to provide for relatively quick opening and slow closing action. The main fluid supply line 2| leads into the cylinder through a check valve 22. This valve may be of any usual type, it being shown diagrammatically for the purpose of this description. .This valve 22 allows the fluid to enter the cylinderfreely, but when the pressure is released, the valve closes causing the fluid to passthrough a bypass line 23. A valve 24 in this line regulates the speed at which the fluid'returns to the pressure source and therefore regulates the closing speed of the doors. It is apparent this valve 24 could be of other types than the needle valve shown and might be a spring loaded, normally closed valve which would hold the door open until released manually from wit in the garage.

The pressure supply system may be made in several different em odiments, several of which are shown in Figs. 2 through 6. In each it will benotedthat there is a plurality of cylinder and pistonlassemblies, at least one piston of which is en aged before the others. More specifically, in the. embodiment of Figs. 2 and 3, the pressure system comprises a base 2! on which are mounted the cylinders 28 and 29. The high pressure cylinder 28 is shown with a smaller diameter than the low pressure cylinder 29 although as previously described, they might well be of equal diameter. With the different diameters as shown, the ratio of the high pressure to low pressure will be greater than 2:1 which would be the ratio were the diameters equal. A high pressure piston 3lland a low pressure piston 3| are disposed in'their respective cylinders 28 and 29; the

operating rods 32 and 33 extending through the upper heads 34 and '35 of the cylinders. cylinders 28 and 29 are connected to a common pressure line 36 which feeds into the supply line2l. V

' A lever 31 is hinged to the base 21 at 39 in position to engage the rods 32 and 33. This lever is formed such that in its downward travel it will engage the high pressure piston rod 32 sometime before the low pressure rod 33. Thus the high pressure piston 39 is forced down by the full weight on the lever 31 causing a high pressure in the line 36 and therefore in the actuating cylinder H. The piston 31 is merely forced up against the upper head 35 during this part of the stroke. Asthe lever'comes down because of the travel of the piston in the actuating cylinder II, it engages the rod 33 and then the force on the lever is balanced between two pistons of much'larger area than the first one alone. As a result, the pressure is decreased, as described above, but

the door will continue to open.

The force on the lever 31 is preferably the result of the weight of an automobile or other vehicle being driven onto the lever 31. To ac- The complish this, I provide ramps 40 adapted to be placed in one lane of a driveway. These ramps are pivoted to a platform portion 41 of the lever 31. Since the lever will necessarily tilt laterally about its hinge 38, it is desirable that the joint of the ramps 49 to the platform 4! be a universal swivelling joint. This may be any of several types of joints, but for this purpose, it is illustrated as a ball and socket joint. 43., Rollers 44 may be provided pivoted to the lower end of the ramp 49 to allow the ramps to move longitudinally when the lever 31 moves downward.

The ramps preferably are of such length that the front wheels of an automobile will still be on one ramp when the rear wheels start onto the other. This will insure pressure on the lever 31 at all times during the passage of the vehicle and thus the length of time of continuous pressure to open the door will be greater.

The lever in this embodiment may be extended as shown to provide a foot pedal 41. This extension must be long enough so that a weight of approximately pounds on it will open the door easily. It is then possible for the doors to be opened from the outside merely by steppin onto the foot pedal .1.

The parts are returned to their normal position by hydraulic action resulting from the T81.

turn of the actuating piston i5 to its original position by the spring 19.

An alternative embodiment which will eliminate the need for the ball and socket joint'43 is shown in Fig. 4. In this embodiment the cylinders 28 and 29 are spaced longitudinally of the device rather than laterally; the high pressure cylinder 28 being placed under the ramp 43 first engaged by the vehicles wheel. The platform 49 in this embodiment is supported by springs 58 at each of its corners. In'order to prevent any except a vertical motion, sliding guides 52yare provided. These may well take the form of a telescoping rectangular box mounted on the platform 49, although the guides may not be necessary on the sides since there will be little lateral force. The ramps 40 in this embodiment are hinged to the platform 49 by a simple straight hinge 53 since the platform does not necessarily tilt laterally.

In operation this device is somewhat different from that previously described, althoughthe principle is the same. In this embodiment, as the vehicle approaches and starts up the left hand (Fig. 4) ramp 40, the springs 59 on that side of the platform are compressed, and-the ramp engages and forces downward the operating rod 32 of the high pressure piston 33. As the vehicle rolls up the ramp onto the platform 49, the springs on the other side of the platform are compressed and the low pressure cylinder and piston assembly are operated to provide the same result as in the prior embodiment. The piston rods 32 and 33 are necessarily placed close to the hinge points 43 and, therefore, the weight of the overhanging part of the ramp 4B is sufiicient for keeping the ramp in contact with the ground instead of pivoting around the piston rod when the vehicle is on the platform 49 or the opposite ramp. A stop 54 is also provided to prevent too great force from being applied to the cylinders. This embodiment is returned to its original position primarily by corner springs 59 leaving only the pistons to be pushed up by the hydraulic'sys- A third embodiment using concentric piston and cylinder means is illustrated in Fig. 5. In

this embodiment a large cylinder 53 is mounted onthe base 54 to which the pressure line 2| is connected. A piston 55 is operably dispos'edin this cylinder and is held within the cylinder'by a ring" 56 fixed to the-top of the cylinder by screws 5Z1. While they are not shown, it will b'e meanest-wh those-skilled in the art that-piston rings and packing glands :oro'then types of sealing mechanism may be provided to prevent leakage of fluid from thiscylinder.

A smaller cylinder 58 is formed in the piston 55 to provide the high pressure necessary for startin'g: 'A piston '5-9 havinga-stem or rod 601s slidably disposed in'the'smaller cylinder with the rod extending through guide portion 62 formed in the large piston. A bar 63 extending laterally is fixed to theend of the rod 60 by some means such as welding. Ears 64 extending upwardly from this bar receive the pins 65 on which both ramps 40 may be pivoted in the well known manner of a hinge.

The operation of this embodiment is similar to that of those previously described. Since the ramps are hinged at a common line over the center line of the cylinders, there are no overhanging loads on the piston, and there will he, therefore, less tendency to binding of the piston in the cylinder. As the small piston reaches the end of its stroke, the bar 63 engages the top of the large piston 55 forcing it down with an effect exactly similar to the action of the two pistons in the prior described embodiments.

Still another embodiment is shown in Fig. 6. In the embodiment shown, the cylinder 61 is formed with a top 58 and guide portions 69, althoughthese portions could be formed from a separate piece and attached to a cylinder similar to that of the embodiment just previously described.

The operating piston iii in this cylinder has a stem H slidably journalled in the guide 69. Above this, I have shown a necked-down section 12 extending upward to a small piston I3. A small cylinder 14 is slidably journalled on this piston 13 and carries a stop 15 fixed to the cylinder i4 and slidably journalled on the neckeddown portion '12. It will be recognized that, if the small piston '23 were made somewhat larger than the stem H, there would be no need for a necked-down section 12 as shown. A compression spring 16 may be disposed in the small cylinder 14 between the head I! of the cylinder and the piston 13. This spring is held in a recess 18 in the cylinder so that before it is completely compressed, the cylinder presses on the piston to force the large piston 16 downward. A passageway ?9 is formed through the pistons and their stemsto connect the two cylinder chambers.

The head ll of the small cylinder M may be formed with extensions thereon similar to the bar 63 of the previously described embodiment. Ears 65 holding the pin 65 on which the ramps 48 are journalled are exactly similar to those previously described.

The operation of this embodiment of pressure apply system is the same as that described above. As the liquid is forced through the passageway 19 into the tube 2| to the actuator, the cylinder l4 reaches the end of its travel and engages the stem of piston 19, forcing that piston downward with the same effect as previously described.

The application of my device to a lifting type gate is illustrated by Fig. 7. A gate 82 formed of a series of parallelograms having pinned, pivotal joints is hung on a post 83. The actuator as- 6 sembly of my-zdeviceiis calso ffirmly mounted ion this post. The cable lli, 'whichiis adapted to opcrate the gate :82, :extends from. the drum .11 .over. a pulley 8'4 Tait thetop "of 'thepost 83 and is fastened at its other end to an eye 85 suitably fixed thegate.

As the vehicle approaches the gate, the actua-, tor is operated by thepressuresupply system as previously described, and the cable 18 is woundon the drum IT. This causes the gate tot-rise to the position shownby the dashedlinesin Fig. 7. As the vehicle passes, the gate will close slowly at a rate dependent on the adjustment of the bleed valve -24 (Fig. 1). It is apparent that a "p're's'sure system could be put at both sides of the 'gate merely by using a T connection in the pressure line 2|. This would make it possible to open the gate upon approaching from either direction.

A simple application of my device to an overhead garage door is illustrated in Figs. 8 and 9. The door 81 is hung from brackets 88 fixed to an axle 89. These brackets are preferably welded to the axle to prevent any relative motion therebetween. This axle is journalled at both ends in a bearing carried by a housing 99 mounted on a bracket 9| which, in turn, may be fastened to the studdings or corner posts 92 on the inside of the garage. A pulley 93 is fixed to the axle 89 in a position where it may be operated by the actuator of my device. Since the door, and therefore the pulley, moves through only a quarter of a turn, it is apparent that a larger pulley can be used for cable operated doors.

I prefer this type of door because there is little or no twisting strain on the door as it is being operated, all that strain being taken in the axle 89. However, this description is not to be interpreted as limiting the invention to applications of my device to this particular type of door. It will also be apparent that, if a single deviceis not effective to open the door, a pair could be used simply by mounting the other actuator on the opposite side of the door and another pressure supply unit in the other runway of the drive. However, for the ordinary usage, such double installation will not be required.

Other embodiments will be obvious to those skilled in the art. For example, the cylinders might be placed individually in a staggered arrangement in a single path of the driveway, or preferably one in each path so that both. would be operated at the same time, although the high pressure cylinder would be started first. It is also apparent that more cylinders could be used provided the effect were the same.

Thus, it is apparent that I have provided a door opener which is inexpensive and sturdy, requiring no auxiliary source of energy, and capable of opening a door or gate fully merely by the Weight of an automobile.

Having thus described my invention, I am aware that numerous departures may be made therefrom without departing from the spirit or scope of my invention.

I claim:

Operating means for a hydraulic door opener comprising a base, a platform pivotally attached along one end to said base and having a portion extending over the base, the parts of which are parallel to the base transversely of the platform, a plurality of cylinder means mounted on said base at different distances from the pivotal connection, the cylinder nearest the pivotal connection being of smaller diameter than the others, pistons slidably disposed in said cylinders, oper- 7 ating'means for said pistons adapted to be engaged successively by said platform in order of distance from said pivotal connection, and ramp means connected to said platform by a universal joint.

CHARLES G. G. GROUP.

REFERENCES CITED UNITED STATES PATENTS Number V Name Date 1,421,002 Hagen June 27, 1922 1,921,008 Shinn Aug. 8, 1933 Number Number 289,158

8 Name Date Engel Nov. 13, 1934 Cox Oct. 20, 1936 Miller July 18, 1939 -Staude Aug. 8, 1939 Dodge -1 July 2, 1940 Haynes Aug. 18, 1942 Edgemond Dec. 28, 1943 Forbes Feb. 8, 1944 FOREIGN PATENTS Country Date Great Britain Oct. 19, 1927 France Dec. 24, 1929

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