US1953262A - Fluid motor for windshield wipers - Google Patents

Description

V April 3, 1934. PQLICE 1,953,262

FLUID MOTOR FOR WINDSHIELD WIPERS Filed Dec. 7, 1931 v ZJwafcZZ0/zte, 5 :8 22 fl MQAM l atented Apr. 3 193 4 TAES PATENT oFFicE 6 Claims.

My invention relates to improvements in a fluid motor adapted, for example, to operate mechanism for actuating the wiper of a wind shield cleaner.

The objects of the invention are to provide an improved motor or" compact, simple construction capable of manufacture at a minimum of cost; to provide in combination with the motor an improved linkage for operating the actuator for the wiper; to provide in such linkage means for reversing the action to enable the motor to use either air or vacuum as the motor fluid; and, lastly to provide an improved valve control mechanism in association with the motor.

01 course, other important objects will become apparent to those skilled in this art as the disclosure is more fully made.

Such objects are briefly achieved by the form of the invention herein shown for purposes of illustration, in which form the motor comprises a cylinder, or tube, in which a single piston is mounted for reciprocation. The piston rod of the piston projects slidably through a cylinder head into a supplementary chamber to operate an improved linkage. Such linkage operates the actuator for the wiper element. An improved valve mechanism arranged outside the cylinder tube controls porting to air or vacuum in an ingenious manner to regulate the reciprocation of the piston, said valve mechanism being moved by the action of a spring connected to the linkage, said spring adapted to be reversed, depending upon whether the motor fluid to be employed is air or vacuum. A hand control and cut-off lock are also provided. For the present this will sufiice in presenting a general View of the structure.

In the accompanying sheet of drawing the preferred, illustrative example for a practicable construction has been shown. In the drawing:

Figure 1 is a general plan View of the motor with a portion of the body broken away to show the actuating mechanism;

Figures 2 and 3 are vertical sectional views as seen along the line 3-3 in Figure 4, looking in the direction of the arrows, and respectively showing the opposite extreme positions assumed by the linkage under the influence of the single piston;

Figure 4 is a view, on an enlarged scale, looking into the right hand end of the structure as seen in Figure 2;

Figure 5 is a detail view as seen along the line :5-5 in Figure 4 to show the cut-off means, as seen when looking in the indicated direction; and

Figure 6 is an end view similar to Figure 4 on a reduced scale, but showing a modified form of the invention.

The motor comprises a body in theform of a tube or cylinder 10 closed at one end by a cap 11 which may be screw threaded or otherwise removably fixed in place. The opposite end of the cylinder is closed by an integrally formed head or wall 12 and beyond this head or wall the body or cylinder may be appropriately elongated to provide a supplementary chamber 13, as shown. Slidably mounted in the cylinder is a single piston 14 secured to the end of a piston rod 15, said rod mounted in a seal packing 16 carried centrally in the head 12.

The piston rod has its free end projected into the supplementary chamber 13 as best shown in Figures 2 and 3, said free end having pivotally connected thereto the bifurcated end (see Figure 1) of a pitman or link 17, which link is formed with an upwardly extended arm 18, and an oppositely, or downwardly extended arm 19. See Figure 4. The other end of said link 17 is also bifurcated for pivotal connection at 20 to a second link or crank 21. The link 21 has it other end fixedly connected to a rock shaft 22 appropriately passed through and journaled in the lower part of the chamber 13, said shaft having a handle 23 at one end for manually rocking the same-while the other exposed end of this shaft 22 is formed at 24 to mount a squeegee or windshield wiper element of any standard construction, and therefore the same has not been shown. In other words, shaft 22 is the actuator for the wiper and the links 17 and 21 form a linkage comprising a pitman and crank for rocking the actuator to oscillate the wiper, as the piston 14 moves to and fro.

A side wall of the supplementary chamber 13, as best shown in Figure 4, is provided with a pin 25 to mount pivotally, intermediately of its ends, a lever 26 which is disposed in a vertical direction with its upper end curved inwardly at 27 near the top of the chamber 13, and with its lower end also curved inwardly at 28 near the bottom of the chamber 13. A trigger spring 29 to snap the lever 26 is shown best in Figure 4, said spring adapted to be connected either between the end of arm 18 and the lower end 28 of lever'26, or between the end of arm 19 and the upper end 27 of the lever 26.

The purpose of this reversible spring arrangement is to enable use of either compressed air from a suitable source of supply, or vacuum from an engine, to serve as the motor fluid for the windshield wiper motor. In Figure 4 the connection is for air, and in Figure 6 is shown the hook-up for the spring 29 when vacuum or suction is tobe employed.

Adjacent its lower end the lever 26 is provided with a hole 30 (see Figure 5) into which is hooked the bent end 31 of a piston type valve stem 32. This stem 32 extends into a bore 33 formed outside the cylinder 10 said bore or passage being open into the open ended chamber 13 and also open to atmosphere at its opposite end as shown in Figure 3. At opposite ends of the bore are provided ports 34 and respectively leading from said bore to opposite ends of the piston chamber 10. t The stem 32 carries piston type valves 36 and 37 respectively to control porting and venting as will later be described. About midway between the ports 34 and 35 the bore 33 is provided with a lead 38 through which air or vacuum enters the motor to operate the same.

The same wall or side of the chamber 13 which carries the lever 26 may also rockably carry a pin 38 having an end bent upwardly as appears in Figure 4 to provide a small handle 39. Inside the chamber 13 the pin 38 carries a cam (see Figure 5) having a flat or low side 41 which when swung to the dotted line showing in Figure 5 permits the lever 26 to oscillate. The cam 40 also has a high or rounded side to project into the path of movement of the lever 26 to serve as a lock whereby to prevent operation or oscillation of said lever '26 as shown in the full lines in Figure 5. The cam thus provides through the hahdle 39 a manual but off for the motor. A stop 42 is provided on the wall 12 to limit the movement of the lever 26. The high part of the cam 40 holds the lower end of the lever 26 against the shaft 22. The operation of the mechanism above described will now be summarized.

For purposes of illustration, in the main fig ares, the spring29 is connected in the drawing for eo'mpres'sed air as the motor fluid to be employed. Thus, in Figure 2 the piston 14L is at its. extreme left hand position. Air comes through the lead 88 and passes to the left in the bore 33, thence through port 34 into the cylinder l0 between the end cap 11 and the single piston 14. In this position the valve 36 has uncovered the port 34 and valve 37 has closed 011? the port 35 from the source of air supply. In-- stantly then, the piston 14 travels to the right with the compression side of the cylinder 10 venting through the port 35 and out the open end the bore 33. The p'iston rod 15, of course, also moves to the right to move the pitman 1'7, and crank '21, thereby rocking the actuator or shaft 22 to cause the wiper mounted thereon to swing. This jack knifes these parts and causes thesp'ring -29 to pull the lower end of the lever 26"froin. the left as seen in Figure 2 to the right as seen infFigure 3 and as this lever so moves, it, pulls on the stem 32 to reverse the position oi' the piston'val ve's 36, 3'7, relative to their respective ports '34, 35. In practice friction losses and lost motion between loose pivot connections of the end of the piston rod '15 to the link and crank parts17, 2i, and in the linkage itself, and because'the spring 29 is relatively weak enables the piston 14 to have as much travel as shown in Figures 2 and 3. Thus the arm 18 can in fact travel as far beyond the center line of the lever 26 assho wh in Figure 3, although if such lost {motion and friction losses in the pivots were not present the arm 18 would not move so far to the right as appears from Figure 3 and would result Conseduently, the air now passes into the cylinder 10 through the port 35 which has been uncovered, thereby causing the piston to move to the left w h the port 34 and open end of the bore 33 adjacent said portfserv-ing to vent the compression side of the cylinder at this time. This now ioauses'the actuator shaft 22 to rock with the wiper, not shown, in the opposite direction. Thus, the motor continues in operation to oscillate the wiper. By means of the handle 23 the shaft 22 may be rocked manually to set the wiper when the fluid power is not being applied as will be readily understood. By means of the handle 39 the eccentric 40 may be used to lock the lever 26 against operation and in this fashion the motor will be out 01f to hold the wiper out of operation when the same is not needed.

If vacuum or suction is employed as the motor fluid, the spring 29 is then simply disconnected from the arm 18 and end 28 of the lever 26 and instead is connected between the end 2'. of said lever 26 and the arm 19 'of the pitman 17. See Figure 6. The operation of the motor will then be such as to produce the same result, except that the piston will be sucked instead of pushed as will be readily understood.

For example, the parts such as the piston 14, link and crank 17, '21 will be in exactly the starting position shown in Figure 3, except that the spring 29 will now be connected between the extension 19 of pitman link arm 1'? and the upper extension 2'? of the lever 26. Such hook up of the spring 29 exerts a force to reverse the position of the valves 36, '3"? bywhich is meant that the valves are forced by thespring acting on lever :26 to the extreme left hand position to open the port3fl to the vacuum and close port 35 by the valve 3'? to the vacuum, but to admit atmospheric air through port35 behind the piston 1 Siuch position of valves 36, 3'? is shown in Figure 2, but the piston 14 would be in the position shown in Figure 3. Thus, the piston 1% must move to the left and its rod 15 pulls the link and crank parts up and to the left and the spring 29 is effective to snap the lower end of lever 26 to the right to shiftthe valves 36, 3'7 to the right to open port 35 to vacuum and open port to the atmosphere. Thereupon the piston 14 is drawn by vacuum from its backside and pushed by atmosphere from its head end to the right, and so on back and forth as will be understood. Thus when operating on vacuum the parts function as when compresed air is used except that the spring is hooked up differently to cause the valves 36, 3'7 to work reversely with respect to the piston movement.

The throw of lever 26 at its lower end is controlled by the stop 42 in one direction and by the shaft 22 in the other direction, said shaft serving as a stop. Thus, the linkage can never throw over dead center and lock.

From this disclosure it will now be appreciated that an improved motor has been provided which achieves all of the desirable objects heretofore recited.

It is the intention to cover herein all such changes and modifications of the example herein shown as do not depart from the spirit and scope of my invention as indicated by the definitions thereof, constituting the apended claims.

What is claimed as new is:

1; A fluid motor or the class described, comprising a cylinder closed at both "ends, a piston reciprocable therein having a piston rod passed slidably through one'end,-a pitman link pivotally connected to the rod outside the cylinder, said pitman link provided with an outstanding arm, a crank pivotally connected to thepitman link, an actuator shaft rockably carried adjacent the 'end of the cylinder, the crank being fixed to the shaft, a leverpivo'tally mounted adjacent the pitman and crank mechanism, said lever having a bent end; a spring connected between the arm and bent end of the lever, a passageway adjacent the cylinder having a port adjacent each end thereof communicating with the cylinder at opposite sides of the piston, means to lead fluid to the passageway, a pair of valves slidably arranged in the passageway, a stem carrying the valves, and means connecting an end of the stem to the lever to slide the valves.

2. A fluid motor of the class described, comprising a cylinder closed at both ends, a piston reciprocable therein having a piston rod passed slidably through one end, a pitman link pivotally connected to the rod outside the cylinder, said pitman link provided with an outwardly projected arm, a crank pivotally connected to the pitman link, an actuator shaft rockably carried adjacent the end of the cylinder, the crank being fixed to the shaft, a lever pivotally mounted adjacent the pitman and crank mechanism, said lever being positioned upright and havin an end bent laterally, a spring adapted to be connected between the free end of the arm and the free end of the bent end of said lever, a passageway adjacent the cylinder having a port adjacent each end thereof communicating with the cylinder at opposite sides of the piston, means to lead a motor fluid to the passageway, a pair of valves slidably arranged in the pasageway, a stem carrying the valves, and means connecting the lower end of the lever with a free end of the stem to slide the valves.

3. A fluid motor comprising a cylinder closed at both ends, a piston reciprocable therein having a piston rod slidable through one end of the cylinder, a pitman pivotally connected to the end of the rod outside the cylinder, said pitman carrying an oifset arm between its ends, a crank pivotally connected to the other end of the pitman, an actuator shaft carried rockably and transversely across the end of the cylinder adjacent said crank, said crank having its other end fixed to the shaft, a lever pivoted on a transverse axis adjacent the pitman and crank mechanism, said lever having an offset end, a spring connected between said end and the pitman arm, a passageway provided adjacent the cylinder having a port adjacent each end thereof communicating with the cylinder at opposite sides of the piston, means to lead motor fluid to the passageway, valve mechanism slidable in the passageway, a stem. for said valve mechanism, and means connecting the lever to an end of said stem to operate the valve mechanism.

4. A fluid motor comprising a cylinder closed by a cap at one end and a head at the other, said cylinder having a supplementary chamber adjacent the head, a single piston slidable in the cylinder, said piston having a piston rod slidably carried to project through the head into said chamber, an actuator shaft journaled rockably and transversely across the head in said chamber, a pitman and crank in said chamber, the pitman being pivotally connected between the rod and crank and the crank having one end connected to the shaft to rock the latter, an oiiset arm located on the pitman between its ends, an upright lever pivoted on a transverse axis in said chamber, a spring connected between the arm and lever, a passageway adjacent the cylinder having ports communicating with the cylinder on opposite sides of the piston, valves in the passageway for controlling passage of fluid into the cylinder, means to lead motor fluid into the passageway, and means connecting the valves for operation from said lever.

5. A fluid motor comprising a cylinder closed at both ends, a piston reciprocable therein having a piston rod slidable through one end of the cylinder, a pitman pivotally connected to the end of the rod outside the cylinder, said pitman carrying an offset arm extending laterally and up-' wardly from between its ends, a crank pivotally connected to the other end of the pitman, an actuator shaft carried rockably and transversely across the end of the cylinder adjacent said crank, said crank having its other end connected to the shaft to rock the latter, an upright lever pivoted intermediate its ends adjacent the pitman and crank mechanism, said lever having its lower end extended transversely inwardly, a spring connected between said extended end and the upper end of the arm on the pitman, a valve mechanism for regulating porting and venting of motor fluid to opposite sides of the piston, and a stem connected to the lever for operating the valve mechanism.

6. A fluid motor comprising a cylinder closed at both ends, a piston reciprocable therein having a piston rod slidable through one end of the cylinder, a pitman pivotally connected to the end of the rod outside the cylinder, said pitman carrying an offset arm extending laterally and downwardly from between its ends, a crank pivotally connected to the other end of the pitman, an actuator shaft carried rockably and transversely across the end of the cylinder adjacent said crank, said crank having its other end connected to rock the shaft, an upright lever pivoted intermediate its ends adjacent the pitman and crank mechanism, said lever having its upper end extended transversely inwardly, a spring connected between said extended end and the lower end of the arm on the pitman, a valve mechanism for regulating porting and venting of motor fluid to opposite sides of the piston, and a stem connected to the lever for operating the valve mechanism.

EDWARD POLICE.

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