US3149538A - Hydraulic servo-mechanism - Google Patents

Description

P 1964 G. BROLLO 3,149,538

HYDRAULC SERVO-MECHANISM Filed June 1, 1962 INVENTOR ATTORNEY United States Patent Ofiice Patented Sept. 22, 1964 3,149,538 HYDRAULKC SERVQ-MECHANISM Giuseppe Brollo, Viale Fulvio Testi 49, Milan, Italy Filed June 1, 1962, Ser. No. 199,459 Claims priority, application Italy Apr. 20, 1962 1 Claim. ill. 91-337) The present invention relates to a hydraulically operated device for actuating a mechanism including a piston controlling a valve, particularly for valves used in washing machines.

It is one object of the present invention to provide a hydraulically operated device, as set forth above, which can be actuated by water supplied under normal pressure from the available mains. The use of the device is particularly advantageous as a replacement for a motor producing a rotary or an oscillating motion.

It is another object of the present invention to provide a hydraulically operated device for actuating a mechanism including a piston controlling a valve, comprising a hydraulic cylinder communicating with tubes leading to a valve which, on receiving pressurized fluid, for example, water supplied from a water main, brings about alternate feeding of fluid to the opposite sides of a piston, reciprocating in the cylinder, the piston being connected with the device as well as with the movable part of the valve, in order to obtain the desired feeding of the fluid in conjunction with an elastic positioning element effecting a rapid change from one working position to another of the above stated movable part of the valve.

With these and other objects in view, which will become apparent in the following detailed description, the present invention will be clearly understood in connection with the accompanying drawing, in which:

FIGURE 1 is a cross-section of the device designed in accordance with the present invention, in one operative position;

FIG. 2 is a cross-section of the device similar to that of FIG. 1, yet indicating another operative position; and

FIG. 3 is an elevation of the valve body.

Referring now to the drawing, the present device comprises a cylinder 1 having a piston 2 reciprocating therein, a piston rod 3 being pivotally secured to a bar 4, extending from a double-armed lever 5, which is pivoted on a shaft 5 in such manner, that the forward stroke in the direction of the arrow A and the return stroke in the direction of the arrow B of the piston 2 causes the oscillation of the double-armed lever 5 in the direction of the arrow C and in the direction of the arrow B, respectively, the oscillation being performed for a predetermined angular stroke.

The present mechanism may be applied to a spraying element equipped with ejector nozzles for spraying washing Water on the dishes and/or utensils. Instead of arranging an oscillating lever, a wheel may be suitably attached to the piston rod 3 with a connecting rod and a crank (not shown), to obtain a rotary instead of an alternating movement for different applications.

In the example shown in the drawing, the lower part of the lever 5 is pivotally connected by means of an arm 8 to a guide 9 which slides along a track 10 and is provided at its upper portion with a spring 11 between two projections 12 of the guide 9 and the spring 11 is secured near its center 7 to an arm 13 of a movable member 14 of a valve 15 adapted for alternate feeding of fluid.

A pressure spring 16 is disposed axially in the arm 13, urging a small ball 17 outwardly which finds its seat in either one of two recesses 13 and 19, respectively, which recesses are spaced apart for a distance equal to the angular rotation of the valve 15, corresponding with the oscillating movement of the lever 5 and also corresponding with the movement of the mechanical element to which the device is to be applied.

A curved surface 20 is formed between the recesses 18 and 19, which surface 20 acts as a guide for the ball 17 from one to the other position, whereby a movement of the lever 5 in the direction of the arrow D, caused by the pressurized fluid, moves the arm 8 and the latter slides the guide 9 in the direction of the arrow E (FIG. 1) and hence tensions the spring 11 on its right portion, as shown in FIG. 1, until it causes angular displacement of the arm 13 in the direction of the arrow F when the tension of the right portion of the spring 11 is such, to release the ball 17 from the recess 18 carrying it to the other recess 19 and from there back to the recess 18 upon a release movement, as soon as the left portion of the spring 11 is sufficiently expanded at the end of the stroke of the double-armed lever 5 in the direction of the arrow C and thus also by each piston stroke.

The reciprocating movement of the piston 2 is obtained by means of pressurized fluid fed into the cylinder 1, preferably, by water supplied by available water mains, which is fed alternately into the chambers 24) and 21 of the cylinder 1 by means of the water pipes 22 and 23 which operate alternately as feeding pipes and discharge pipes of the fluid into and out of the cylinder 1.

In order to achieve this end, a fluid diverter or distributor valve 15 is provided, which comprises an immovable hollow member 24 having four radially disposed channels 25 spaced apart for an angle of for pas-sage of water therethrough, the immovable hollow member 24 having a, preferably, conical recess, and a rotatable member 14, having the configuration of a truncated cone complementary to the conical recess in the member 24, is turned, for instance, for an angle of 90 in the direction of the arrow P or in the opposite direction of the arrow G, driven by the arm 13, which projects radially from and integrally with the rotatable member 14 of the valve 15.

The rotatable member 1 is equipped with a first pair of diametrically oppositely disposed peripheral grooves 25 and 27 arranged in a plane indicated by the section lines 1-1 of HG. 3, and a second pair of diametricafly oppositely disposed grooves 28 and 29 indicated by the section lines 22 of FIG. 3, in such manner that in relation to the position assumed by the rotatable member 14 in respect to the immovable member 24, the grooves 26 and 27 connect the fluid feeding pipe 30 and the fluid discharge pipe 31 with the pipe 23 as water feeding pipe and with the pipe 22 as water discharge pipe, as shown in FIG. 1 or in reverse direction with the pipe 22 as water feeding pipe and the pipe 23 as water discharge pipe after the arm 13 has performed a turn of about 90, as shown in FIG. 2, so that the fluid is alternately fed to the chambers 20 and 21 of the cylinder 1, causing the piston 2 to move in the direction of the arrow B or in the direction of the arrow A.

As clearly indicated in PEG. 1, the fluid entering from the feeding pipe 31) passes the peripheral groove 26 and is fed into the pipe 23, and then into the chamber 21, thereby moving the piston 2 in the direction of the arrow B, while the fluid in the opposite chamber 20 of the cylinder 1 is discharged through the pipe 22 leading into the groove 27 and then to the discharge pipe 31. When the double-armed lever ,5 reaches the end of the angular stroke in the direction of the arrow D, the guide 9 has caused a rotary movement of the arm 13 in the direction of the arrow F, bringing about a rapid reverse of the supply with the result that the fluid, as shown in FIG. 2, enters from the feeding pipe 31 into the groove 28 and then into the pipe 22, leading to the chamber 20 and thereby urging the piston 2 in the direction of the arrow A, which is opposite to the previous movement of the piston in the direction of the arrow B, While the fluid in the chamber 21 will be discharged through the pipe 23, the groove 29 and the discharge pipe 31. This operation is automatically repeated.

While I have disclosed one embodiment of the present invention, it is to be understood that this embodiment is given by example only and not in a limiting sense, the scope of the present invention being determined by the objects and the claim:

I claim:

In a hydraulically operated device for actuating a mechanism the combination of a hydraulic cylinder,

a piston having a piston rod reciprocating in said hydraulic cylinder and defining chambers on opposite sides of said piston in said hydraulic cylinder,

a feeding conduit coordinated to and terminating in each of said chambers of said hydraulic cylinder,

with a distributing valve feeding fluid alternately to said chambers of said hydraulic cylinder in order to bring about a reciprocating movement of said piston in said hydraulic cylinder,

a double-armed lever having a bar laterally extending therefrom and pivotally mounted intermediate its ends,

the free end of said bar being pivotally connected to the free end of said piston rod,

a guide spaced apart at a predetermined distance from said distributing valve and disposed in a plane perpendicular to the longitudinal axis of said distributing valve,

an arm pivotally connected with one end of said doublearmed lever and With one end of said guide, so that the latter performs a reciprocating movement relative to said distributing valve,

the latter comprising an immovable member having a conical recess and a rotatable member of frusto conical configuration and received in said conical recess of said immovable member,

a shaft extending axially from and secured to said rotatable member and a radially disposed arm projecting from the free end of said shaft,

said guide having a cylindrical face opposite said distributing valve and having a radius identical with the length of said radially disposed arm,

a spring biased ball embedded in the free end of said arm, and said cylindrical face of said guide having two recesses spaced apart at an angle of 90 and receiving said ball in respective operative positions of said rotatable member,

said guide having projections disposed at its opposite 4 ends and receiving the ends of a helical spring at said projection and said arm being secured to about the center of said helical spring, thereby tending to retain said arm in an intermediate position,

said immovable member having four radial bores spaced apart from each other at an angle of a feeding pipe secured to and communicating with a first one of said radial bores,

a discharge pipe secured to and communicating with a second one of said radial bores, the latter being placed diametrically opposite said first one of said bores,

one of said feeding conduits to said hydraulic cylinder being secured to and communicating with a third one of said radial bores,

the other of said feeding conduits being secured to and communicating with a fourth one of said radial bores, and

said rotatable member of said distributing valve having two peripheral grooves disposed diametrically opposite each other for a length of 90 in a plane perpendicular to the longitudinal axis of said rotatable member and connecting alternately said feeding pipe and said discharge pipe, respectively, with said respective chambers of said hydraulic cylinder, and

each stroke of said piston reciprocating said rotatable member of said distributing valve for an angle of 90, by means of said double-armed lever, said guide and said arm of said rotatable member, thereby communicating said feeding pipe and said discharge pipe alternately with said peripheral grooves.

References (Iited in the file of this patent UNITED STATES PATENTS 75,153 Gray Mar. 3, 1868 587,361 Dorau Aug. 3, 1897 967,565 Rohan Aug. 16, 1910 1,458,922 Rivera June 12, 1923 1,511,656 Congdon Oct. 14, 1924 1,661,466 Cook Mar. 6, 1928 1,811,579 Gerling June 23, 1931 1,857,719 Gerling May 10, 1932 2,014,997 Auger Sept. 17, 1935 2,131,910 Vernon et a1. Oct. 4, 1938 2,668,549 Lebus Feb. 9, 1954 2,679,237 Euverard May 25, 1954 2,804,055 Hill et a1. Aug. 27, 1957 FOREIGN PATENTS 215,537 Germany Nov. 1, 1908 480,280 Italy Apr. 24, 1953

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