US2786671A - Timing devices for laundry folding machines - Google Patents

Description

March 26, 1957 E. J. HOWLETT 2,736,671

TIMING DEVICES FOR LAUNDRY FOLDING MACHINES Filed Jan. 13, 1954 2 Sheets-Sheet l ay Mam A ttomeys March 26, 1957 E. J. HOWLETT 2,786,671

TIMING DEVICES FOR LAUNDRY FOLDING MACHINES Filed Jan. l5, 1954 2 Sheets-Sheet 2 Inventor wgw W Attorneys TIMING DEVICES FOR LAUNDRY FOLDING MACHINES Edward John Hewlett, London, England, assignor to Isaac Braithwaite & Sons Engineers Limited, Kendal, England, a body corporate of Great Britain Application January 13, 1954, Serial No. 403,878

3 Claims. (Cl. 270-68) This invention relates to machines for use in laundries for folding sheets, table cloths and other similar articles, and more particularly for such machines of the kind in which the articles to be folded are carried on a ribbon type conveyor over a series of fingers projecting between the ribbons or tapes, these fingers being operated by the leading edge of the article which subsequently comes into contact with the gripping devices actuated through time delay means by the operation of the fingers causing these devices to grip the leading edge of the article and then raise it above the conveyor holding it in that position until the trailing edge is moved away from the fingers, then releasing it so that the latter will fall back into a position more or less coincident with the trailing edge.

In the specification of the prior U. S. Patent No. 2,650,- 821 there is described and claimed a mechanical timing means for effecting the operation of the gripping device on operation of the fingers passing between the tapes and the present invention comprises an improved or modified construction of the mechanical timing device.

In the following description and claims the gripping device will be referred to as the lifting fingers.

According to the present invention the raising of the timing fingers due to the passage of an article through the machine causes the clockwise rotation of a shaft carrying an arm or link on which is mounted, preferably resiliently, a fiat blade which normally holds a pawl carried by a rotatable lever controlling the lifting fingers, out of engagement with ratchet teeth on a disc or wheel continuously rotating in a clockwise direction but which on the raising of the fingers moves the blade away from the pawl and allows the latter to engage the ratchet teeth of the continuously rotating disc or wheel, thereby allowing the pawl and its fulcrum pin or shaft to be carried round with the disc or wheel and this movement of the pawl causes the lifting fingers to grip the leading edge of the article.

The invention is illustrated in and will be described with reference to the accompanying drawings, in which:

Fig. 1 is a diagrammatic side elevation showing the position of the timing device on the folding machine,

Fig. 2 is a side view of the timing device, and

Fig. 3 is a detail sectional view showing the mounting of the pawl on the rotatable lever,

In the drawings the tapes carrying the work through the machine are designated 4, the timing fingers operated by the articles carried by the tapes are designated 5 and the gripping fingers are designated 6 and 6a.

A transverse shaft A which on lifting of the timing fingers 5 by the passage of an article through the machine is caused to rotate in a clockwise direction as indicated by the arrow a Fig. 2 by a member Z linked thereto by an arm Y secured thereto and by an arm 2. secured to a shaft 1 to which the timing fingers are secured. An arm A is secured on the shaft A and this arm carries a blade B which as shown in Fig. 2 is resiliently mounted thereon.

A continuously rotating ratchet wheel D which rotates fitates Patent 0 F 2,786,671 "Patented Mar. 26, 1957' 2 V in the same direction as the shaft A as indicated by th arrow d Fig. 2 is driven from the main shaft of the machine A lever P is secured to a shaft X which is freely mounted concentrically with the ratchet wheel D.

A pawl C is fulcrummed on the lever P and the pawl being provided with a tooth or projection c adapted to be engaged by the teeth of the ratchet wheel D and with an extension 0 which when the timing fingers 5 are in their inoperative position is supported by the blade B to hold the tooth 0 out of engagement with the teeth of the ratchet wheel D. When however the timing fingers 5 are lifted and the shaft A moves in a clockwise direction the consequent movement of the arm A causes the blade B to move away from the extension c of the pawl C so that the latter will move about its fulcrum on the lever P and the tooth c comes into engagement with the teeth of the ratchet wheel D. Consequently the pawl C together with the lever P and the shaft X will be carried round with the ratchet wheel D. A- crank W secured to the shaft X controls the movement of the lifting fingers 6 and 6a through a rod V slidable in a tube V and a crank U secured to a shaft 2 on which the lifting fingers 6 are secured. The tube V is engaged by a collar v adjustable on the rod V.

The pawl C carries a pin E which engages a stationary cam F when the pawl C has travelled through approximately i. e. into the position shown in dotted lines in Fig. 2 and the engagement of the pin E with the cam F causes the pawl to move about its fulcrum thereby disengaging the tooth c from the teeth of the ratchet wheel D and the clockwise movement of the pawl C about the axis of the ratchet wheel to cease. Y

A spring (not shown) and the weight of the lifting fingers then tends to return the pawl C and lever P to their original positions but the movement of the pawl C about its fulcrum has brought the extension 0 into engagement with a hook g on a lever G so that the return movement of the pawl is prevented. The means which tends to return the pawl C to its original position causes the pawl to apply a lifting force to the lever G which is pivotally mounted 'on a pin M whiclris arranged in a slot g in the lever so that the upward thrust applied by the pawl C to the lever G causes the latter to rise to the extent of the slot g as shown in Fig. 2 and while the 'lever G is held in this position the lifting fingers 6' are held in their upper position by the lever P which carries the pawl.

A lever l is arranged below the ratchet wheel D one end of this lever being pivotally connected to the bottom of the lever G and the other end to the bottom of a link H. The upper end of the link H is pivoted on the lever A carrying the blade B. The lever J carries a tripping block K provided with a tooth or projection k adapted to be brought into engagement with the teeth of the ratchet wheel D.

The raising movement of the lever G by the pawl C lifts the right hand end of the lever l and brings the tooth k on the block K nearly into engagement with the teeth on the lower part of the ratchet wheel D. The levers G and J remain in these positions described with the lifting fingers 6 held in their upper positions so long as the timing fingers 5 are raised by the article passing below the latter but when the trailing end of the article passes away from the timing fingers, the falling of the latter causes the shaft A to move in an anti-clockwise direction, thereby lifting the lever A and with it the blade B and also the link H which raises the left hand end of the lever J and brings the tooth k of the block K into engagement with the teeth of the ratchet wheel D. The rotation of the wheel D then causes the lever I to move towards the left which in turn causes the lever G to pivot on the pin M and the hook g to become disengaged from the extension of the pawl C. This disengagement of the pawl C allows the latter to be returned by its spring into its original position shown in full lines in Fig. 2 with the extension c in contact with the blade B which as previously stated has been lifted into its original position. The mechanism is now ready to receive the next article passing through the machine when on the raising of the timing fingers the same cycle of operations is again cornmenced.

It will be appreciated that the pawl C must be free to move on its pivot on the lever P so as to be able to fall into engagement with the teeth of the ratchet wheel D when the blade B falls at the beginning of the cycle of operations but that when the pawl C is being returned from the locked position shown in dotted lines in Fig. 2 it .must not move into engagement with the teeth of the ratchet wheel D until the end of pawl C is again in contact with blade B.

This desired restriction of movement of the pawl C on the lever P is obtained by mounting it on the lever as shown in Fig. 3. In this figure the pivot 0 carried by the lever Pon which the pawl C is mounted is hollow and through it passes the spindle Q, having an enlarged head which is pressed against the face of the pawl C by means of a spring S, the pressure being sufficient to prevent gravitational movement of the pawl. When the pawl C is in the neutral position with its extension 0 in engagement with the blade B the end of the spindle Q is engaged by a stationary cam T which causes end movement of the spindle Q and releases the axial pressure of the spring thereby allowing the pawl C to move under gravity when the blade B moves away from the pawl.

As shown in Fig. l the timing device is arranged in casing 7 mounted on the top of the framework 8 by which the timing fingers and lifting fingers 6 are supported.

Upon raising the lifting fingers 6 the fingers 6a are thereby raised, together with links 12 and 13, causing rotation of a pawl 14 into engagement with a detent in an arm 11. When the lifting fingers are lowered, the fingers 6a are held until a crank R secured to the shaft 2 has raised a slotted link 10 which links it to the arm 11, and lifts the arm 11 through a peg 9, releasing the pawl 14 and allowing the fingers 6a to fall to a position spaced above the lifting fingers 6, at which position, as shown in Fig. 1, they are arrested by the action of a stop 15, secured to the frame 8, on the link 13.

What I claim is:

1[ A timing device for a laundry folding machine of the type referred comprising the combination with the tapes which carry the articles to be folded through the 5 machine of fingers projecting downwards between the tapes and which are raised when the leading edge of an article comes into engagement with them, a transverse shaft on which the said fingers are secured whereby the raising of the fingers causes a rotary movement of the shaft, a second shaft connected to said transverse shaft for transmitting rotary movement from the latter shaft to the second shaft, an arm secured on the second shaft, a blade carried by the arm, a continuously rotating ratchet wheel, a lever capable of moving in a limited are about the axis of the ratchet wheel, a pawl fulcrummed on said lever, the pawl being held out of engagement with the ratchet wheel by the blade on the arm secured to the second shaft when the fingers are not raised but when the fingers are raised the rotation of the second shaft moves the blade away from the pawl and allows the latter to engage the ratchet wheel whereby the lever carrying the pawl is carried round with the ratchet wheel, lifting fingers for gripping and raising the leading edge of the article after the latter has travelled a predetermined distance and means positively connected to and controlled by the movement of the lever carrying the pawl for operating the lifting fingers.

2. A timing device for a laundry folding machine as in claim 1 having a stationary cam surface which is positioned to be engaged by the pawl after the latter has moved a predetermined angular distance about the axis of the ratchet wheel, thereby disengaging the pawl from the ratchet wheel, a hooked lever which is positioned to be engaged by the pawl on the disengagement of the latter from the ratchet to prevent the pawl from returning to its initial position, means operative by the fingers to hold the hooked lever in position to restrain the pawl from return movement and to be released by the fingers to cause rotation of the transverse shaft by falling of said fingers due to the trailing end of the article having passed beyond these fingers whereby the lifting fingers will be held in their gripping and raised position until the trailing edge of the article has moved beyond the first fingers.

3. A timing device for a laundry folding machine as in claim 1 having the pawl so mounted on the lever controlling the lifting fingers that it can freely rotate about its fulcrum when the pawl and lever are in their original positions, and means positioned for operation when the pawl is returning from its operative to its original position to hold the pawl out of engagement with the ratchet wheel.

References Cited in the file of this patent UNITED STATES PATENTS

Images