US2506697A - Hydraulic loom check - Google Patents

Description

May 9, 1950 R. o. BALoGH 2,506,697

HYDRAULIC LOOM CHECK Filed Oct. 12, 1946 2 Sheets-Sheet l INVENTOR. PUY O. BALOH R. O. BALOGH HYDRAULIC LOOM CHECK May 9, 195o 2 Sheets-Sheet 2 Filed Oct. 12, 1946 ATTORNEYS Patented May 9, 1950 2,506,691 HYDRAULIC LooM oimox Roy O. Balogh, Cleveland, Ohio, asslgnor to The Weatherhead Company, Cleveland, Ohio, a corporation of Ohio Application October 12, 1946, Serial No.4 702,953

2 claims. l

This invention relates to a loom mechanism, more particularly to the provision of a novel hydraulic checking apparatus for the picker staff of the loom. This invention is a modification of the device described in my co-pending application, Serial No. 670,252, iiled May 16, 1946, now Patent No. 2,483,517, issued October 4, 1949.

Modern practice in the Weaving art tends towards a steady increase in loom operating speed. One of the problems encountered when attempting to increase the speedof the loom involves trouble with the operation of the shuttle and picker stati. It has been found that if the picker stall? is not checked and brought smoothly to a stop at the end of its return stroke, without oscillation or rebound, that the shuttle is not always received in a predetermined position and erratic casting of the shuttle to the oppositeside of the loom results. Early picker checks have included leather straps which have proven unsatisfactory particularly where the humidity of the atmosphere is subject to variation. Also, such straps are unsatisfactory in that they do not permit accurate adjustment and do not eliminate rebound. The prior art also discloses various pneumatic checks which have proven inferior in that the tendency of the compressed air to reexpand as the picker staii' comes to rest results in serious rebound and poor operation.

I am aware that the broad concept of a hydraulic check for the picker staff is disclosed in the prior art but prior hydraulic devices are subject to numerous objections and have been found unsatisfactory for high-speed operation. Hydraulic checks of the prior art have not been connected to the picker staff but have been merely placed in its path like the old strap or pneumatic check, so that the staff strikes the check operating mechanism towards the end of the return cycle. This arrangement has proven undesirable in that the staff suddenly strikes the check arrangement while moving rapidly, resulting in rebound and erratic operation. This invention, like that described in my aforesaid application, has for an object the elimination of the undesirable characteristics of an abruptly engaged check mechanism by attaching the check mechanism to the picker staff at all times and so designing the check mechanism that it permits unchecked travel of the staii over certain portions of the stroke and provides a smooth checking operation for the end of the return stroke.

It is another object of this invention to provide a hydraulic means so that the stad is brought to a rest in an exceedingly smooth and positive 2 manner without any jarring or rebound. This is accomplished by providing a graduated or metered checking arrangement. Brieiiy, the principle of operation resides in the fact that at the beginning of the checking action where the velocity of the picker staff is high even though a relatively large amount of iiuid is by-passed an effective checking action is produced. As the velocity of the picker is decreased, the uid by-passing passageway is correspondingly decreased which maintains an effective checking action. In this manner the checking action can be held substantially constant regardless of the picker stati velocity so that the picker stai is brought to a smooth stop without rebound.

It is customary in loom construction to move the picker stati on its power or shuttle casting stroke with positively acting mechanism and to return the picker stai to its retracted position with a spring or weight mechanism, there being lost motion in the casting mechanism so that final return may be eiected by means of the spring or weight. In many looms the spring serves the dual function of returning the staff and holding the lower end of the staff in position on a supporting plate. The spring arrangement just described will tend to bring the staff to its completely retractedA position before the sta receives the shuttle. If a hydraulic dampening mechanism is present under these conditions this means that the position of the stai Iin its return stroke when the shuttle strikes it depends upon the delicate construction of the damping orices. The shuttle might strike the sta towards the beginning of the damping stroke or, if the return spring is strong, the staff might be in a completely retracted position when the shuttle strikes it. This results in non-uniform casting of the shuttle or possible reboundingvof the shuttle in case the staff has come to rest when it receives the shuttle. It is an object of the present invention to insure that the shuttle cannot rebound by canceling the return spring pressure a short time before the stair reaches its retracted position whereby the inertia of the shuttle as it strikes the stati returns the stall to its retracted position.

In my design I eliminate all chance of rebound of point where the hydraulic checking action begins.

In this manner the shuttle inertia moves the staf! through the last part of its retract stroke against the uniform checking action of the checking de- 3 vice, and since my novel checking device is made adjustable, it is very simple to start the machine and adjust the mechanism for a given speed so that the shuttle and stai are brought to a smooth stop without rebound.

, Vice is in operation which I accomplish generally by providing for adjustment of a metering pin by remote control means.

A further object of the present invention lies in 5 providing means whereby the final portion of the power stroke of the picker staff may be damped and in the provision of adjustable means to con- 1 trol the amount of damping action.

Another object of the present invention is to reduce the amount of machine work which must be done on the check body and to confine most i of the machine work to the piston which design makes for economical manufacture.

These and othervadvantage's of my invention will be apparent as the following description proceeds.

In the drawings:

Fig. 1 is a simplified view of the picker stai! in the loom showing how my hydraulic check mechanism is connected thereto; l

Fig. 2 is a longitudinal sectional view through my hydraulic check mechanism; and

Fig. 3 is a cross-sectional view taken at 3-3 of 1 Fig. 2.

Referring to Fig. 1, a portion of the loom frame 1 is indicated at L. The picker stafl is shown at S and arm A operated by `conventional loom I mechanism moves the staff on a power stroke to cast the shuttle. 'I'he improvedl check mechanism i is shown at C. In accordance with conventional practice a track I is provided for the shuttle 2 and a head 3 on the picker staff throws the shuttle across the loom when the staff is advanced on the power stroke. The picker staff itself is mounted in a shoe 4 which has a curved surface 5 for rolling on the supporting'` plate 6, the purpose of this arrangement being to approximate a straight line motion of the head 3. Plate 6 has an integral socket 6a for reception of the rock shaft I1 serving as a loom check supporting bar. One end of the assembly is supported by the loom frame as at I8. A flexible strap 1 is passed over an extension 8 of the picker staff and fastened at 9. A spring drum I0 is mounted as at II on the plate 6 and the drum is spring urged to move the picker stai in its retracted position as indicated by the arrow. This description of the picker staff mounting is merely given as a background for explaining the present invention,. the details thereof are immaterial so far as the present invention `is concerned. Any convenient fastening means I4 may be provided to link a rod I5 to a lever I6 in the hydraulic mechanism C. The spring 30 `(Fig. 2) is the balancing spring previously referred to in the general description, one end thereof connects to a movable part of the check `whereas the other end is supported by housing `of the hydraulic mechanism as will hereinafter `be more fully described. The retracting force of `the spring in drum I0 is balanced at some posi- 75 60 to a fixed part of the housing, the inner end tion before the picker stai reaches its fullest retract position by spring 30. For example, assume that the shuttle 2 is approaching the head 3. The picker staff has come to rest a certain distance before it engages the positive stop I9 so that the remainder of the staff travel absorbs shuttle inertia. The check C is mounted so that link I6 moves in the same plane as that of the picker staff.

The check C has a body or house portion indicated generally as at 20 which has a cylinder bore 2| formed at one end thereof, the bore being closed by a closure cap'22. A piston member P, which forms the movable part of the checking elements, has a cylindrical end portion 23 for engaging the walls of cylinder 2 I. The other end of the housing has a cylinder 25 in which ts piston portion 26. The cylinder 25 is closed by an apertured end cap 21 and suitable sealing members are provided in conjunction with both caps 22 and 21 to prevent-escape of fluid under pressure. Thus, the piston is mounted for reciprocation within the housing 20 and supported at each end there being an intermediate chamber or reservoir 24 to receive a supply of fiuid such as oil or any other suitable material. The balance spring 3l) which overcomes the effect of the loom spring mounted in drum- I0 referred to previously, may be mounted inside the cylinder, the fixed end being looped over a bar 3| which bar is urged against a shoulder 3Ia on the housing by the spring. The other end of the spring is mounted in the piston by means of a special member 32 which has portions removed to permit the loop of the spring to hook over a bar 32a on the washer. Washer 32 may be retained in the piston by snap ring 33 or any other convenient structure.

As will be described presently, as seen in Fig. 2 the right end of the piston acts to check the flnal portion of the power stroke whereas the left end of the piston acts to check a substantial portion of the return stroke. The left hand portion of the piston has an` aperture 4U which communicates with metering aperture 4I which, in turn, communicates with an open end 42 of the piston. The passageways 4|! and 4I provide for iiuid communication during the final checking action. In order to permit an initial part of the return stroke to be unchecked, one or more passageways 43 may be drilled inthe piston from the open end thereof which communicate with an annular reduced portion 44. With this arrangement there is free communication from the chamber 42 and the reservoir 24 when the piston is far enough to the right for annular chamber 44 to be opened to the reservoir. -The metering pin has a tapered portion 41 which merges with a cylindrical portion 41a and I prefer that the diameter of the cylindrical portion 41a be slightly smaller than the metering aperture 4I in order to prevent a hydraulic block in case of maladjustment. The metering pin is threaded as at 48 to engage mating threads in the end cap 21 and may have an end member 49 which is turned by member 50 operated by a remotely controlled flexible shaft and handle arrangement indicated generally at H. The details of the flexible shaft form no part of this invention and I contemplate that any suitable means may be employed to rotate the metering pin. I may mount this flexible-shaft assembly by means of'collar 5| attached to the cable guide and nut 52 threaded to the cap 21 on the check device.

'I'he operating lever I6 may be pivoted as at of the lever being pivotally connected to an operating block 6| by pivot means 82. A flexible cover 84 is provided. 'Ihe operating block may fit in a guide recess or aperture 63 in the piston, the arrangement being such that rotation of lever I reci-procates the piston P within the cylinders. A by-pass passageway 35 connects the reservoir to the cylinder 2| and the flow through this passageway may be regulated by a metering screw 36 threadedlyattached to the housing 20 in any convenient manner;

In describing the operation of the device, the relationship of parts shown in Fig. 2 is that which occurs when the picker staff is substantially at rest and ready for a power stroke as indicated in Fig. .1. As the arm A starts the staff on the power stroke the piston P is moved to the right and uid in chamber 2| displaced by the portion 23 of the piston, can pass through apertures 34 in the piston and into the reservoir. This action continues until towards the end of the power stroke when apertures 34 are closed off byy the wall 2| of the cylinder. Now, any additional fluid displaced to the reservoir must ow through the bleed passageway 35. Depending upon the adjustment of the metering pin 36, this provides a final checking or damping action to insure smooth operation during the end of the power stroke.

On the return stroke the piston is moved to the left whereupon fluid reverses its flow through the passageway 35 and passes from the reservoir into the chamber 2|. This arrangement provides a certain amount of resistance to the initial portion of the return stroke but ample power is available in the loom mechanism to overcome this resistance. After a small portion of the return stroke Ihas been completed apertures 34 again open to the reservoir and then begins an unchecked portion of the return stroke. However, the parts are arranged so that before the return stroke is completed tapered portion 41 in the metering pin begins to enter metering aperture 4I. Likewise, the by-pass annulus 44 is being closed oif by the edge 45 of the cylinder, and as the annulus 44 is closed off fluid is forced in the small space between the metering pin and its aperture. This begins the graduated or progressive checking action, and due to the taper of the metering pin the fluid restriction increases as the end of the return stroke is approached. When the tapered portion of the pin iirst enters the metering aperture the piston is traveling rapidly and the by-pass orifice is relatively large. Although a substantial amount of iluid can be displaced, since the piston is moving rapidly the fluid velocity and hence the checking action will be appreciable. As the return stroke continues, the effective by-pass aperture is steadily decreased but the piston velocity decreases with it, so that checking action may be. maintained substantially constant. 'I'his action continues until the piston isbrought to a smooth stop at the end of its return stroke. I have found that with the type of loom construction illustrated that no check valve is required for the initial part of the next power stroke. The operating member A is generally operated by means having suilcient power to rapidly initiate the next power stroke even though there will be a tendency for a vacuum to build up in chamber 42 requiring rapid reversed flow of fluid from the reservoir past the metering pin I1. However, with the balance spring construction illustrated, wherein the spring 30 balances the picker staff spring before the end of its return stroke, the amount of hydraulic checking required to bring the parts to a smooth stop is not excessive and it is possible to provide a large enough orifice between the metering pin and the metering orifice to permit action to take place without the use of a check valve. The ad- Justable metering pin 31 can be set so that the ilnal checking action of the cylinder absorbs the inertia of the rapidly moving shuttle as it strikes the picker stall, the yoke I3 of the driving arm A having enough clearance to permit the picker staff -to come to rest before the completion of its return stroke. If balancing spring 30 is omitted, the device can be made operative by adjusting the metering pin to produce a slightly greater checking action in order to prevent the picker staff from bouncing against the stop portion i9 ofthe loom. This slightly greater checking action would be necessary if spring 30 were omitted because now the hydraulic units must check the spring I0 in the loom as well as the entire inertia of the picker sta. It is also understood that I can contour the tapered portion 41 of the metering pin to produce any desirable characteristics of ratio between picker staff velocity and checking action. y

Although .I have illustrated a preferred embodiment, it is understood that various modifications can be made therein without departing from the spirit of the invention, and I contemplate that the appended claims rather than the aforedescribed embodiment be determinative of the scope of my invention.

Having thus described the present invention so that others skilled in the art may be able to understand and practice the same, I state that what I desire to secure by Letters Patent is defined in what is claimed.

What is claimed is:

1. A hydraulic check device for the picker stall of a loom comprising a fluid reservoir, a pair of cylinders each having one end closed and the other end opening to the reservoir, a piston in each cylinder, means to by-pass uid from each cylinder to the reservoir, means to close oil the associated by-pass means as a piston moves a substantial distance into a given cylinder, means for operatively connecting the pistons to the picker staff so that as one piston enters its cylinder the other is withdrawn from its cylinder, fluid metering means operative to check motion of said piston in one direction after the associated by-pass has closed, said uid 'metering means comprising a fluid passageway leading from one cylinder to the reservoir formed in one of associated piston and cylinder means, and means carried by the other of said associated piston and cylinder means for progressively closing off said passageway in proportion to the position of the piston in the cylinder as the piston continues to enter the cylinder and spring means associated with said check device urging the piston in the other direction, past the midpoint of 'the stroke.

2. A hydraulic check device for the picker staff of a loom comprising a housing having formed therein a fluid reservoir and a pair of cylinders, each cylinder having one end closed and the other end opening to the reservoir, a piston having an element tting in each cylinder, means to by-pass iluid from each cylinder to the reservoir, means to close oi the associated by-pass means as a piston moves a substantial distance into a given cylinder and before the piston completes its stroke, means for operatively connecting the pistons to a. loom picker staiI so that as one piston portion enters its cylinder-the other is withdrawn from its cylinder, and fi-uid metering means for one cylinder and its associated piston element operative to check further entry of the piston element into said one cylinder after the by-pass associated with said one cylinder has closed, said fluid metering means comprising a uid passageway formed in one of said associated piston and `cylinder elements and leading from said one cylinder to the reservoir and means carried by the other of said associated piston and cylinder `elements for progressively closing oi said pasmeans continuing to urge said piston in the aforesaid direction after the piston has reached a midposition wherein the by-pass means for both cylinders are equidistant from their associated closure means.

ROY O. BALOGH.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Y Number Name Date 1,592,373 Lovejoy July 13, 1926` 1,743,959 Dunstan Jan. 14, 1930 1,883,292 Jackson Oct. 18, 1932 1,992,569 Doty Feb. 26, 1935 FOREIGN PATENTS Number Country Date 10,354 Australia June 26, 1933 of 1932 y

Images