US2207818A - Silk screen printing machine - Google Patents

Description

July 16, 1940. E. E. PERRY Er AL 2,207,818

SILK SCREEN PRINTING MACHINE July 16, 1940. E. E. PERRY Er AL SILK SCREEN PRINTING MACHINE 3 Sheets-Sheet 2 Filed June 9, 1939 miv N\ a., M @/M wA///// mi@ f4 Nw WMM hmm July 16, 1940. E. E. PERRY Er AL l 2,207,818

SILK SCREEN PRINTING MACHINE Filed June 9, 1939 3 Sheets-Sheet 5 ffzz. a. f1.9. y

Patented July 16, 1940 I PATENT OF F ICE'.r

SILK SCREEN PRINTING MACHINE Ernest E. Perry and FrankA. Cameron, Worcester, Mass.; said Cameron assigner to :saidv -lipplimmm June 9, 1939, serial No. 278,370

Claims.

This invention relates to a silk screen printing machine, and more particularly to devices for the spreading of paint, lacquer, rubber, or any material capable of -being spread.

'I'he principal objects of the invention include: providing a machine` for spreading asubstance over a certain area, the device beingeasily ,adjustable to spread the substance over any predetermined area up to the capacity of the ma- 1|)y chine; providing a pivoted springheld`.recipro cable spreader or squeegee, the length of its path being variable according to the size of work` to be spread; means for restricting the tilt of the squeegee to the desired angle; means for 15 lifting the squeegeefrom the screen at the ends of its path, up over the residue of the substance being spread and then down to the screen again behind the substance,l to return the latter while spreading on the return stroke; a hinged squeegee and stencil carrier mounting all the operative parts of the machine, including a power source, the hinge being entirely at one side of the work area and automatically adjustable to easily accommodate various sizes of stencil frames without manual attention, and a power operated, automatically reversible means to travel the ysqueegee a desired distance within the limits of the machine.

Further objects are the provision of an improved stencil machine which is superior in point of simplicity and inexpensiveness, with a wider range of usefulness and variation of the working area. l

Other objects and advantages of the invention $5 will appear hereinafter.

Reference is lto be had'to the accompanying drawings, in which f Fig. 1 is a plan view of the entire machine:

Fig. 2 is a detail view of the transmission reversing rackand pinion, looking in the direction of the arrow 2 in Fig. 1;-

Fig. 3 is a side elevation of a part of the device, looklng in the direction of the arrow 3 in u Fig. 1:

Fig. 4 is an end view, partly in section, on the line 4-4 of Fig. 3, some parts being broken away;

Fig. 5 is a perspective view oi' the adjustable 50 cam used to lift the squeegee carrier;

Fig. 6 is a perspective view of the cam v to limit the tilt of the squeegee;

Fig. 7 is an end elevation showing the adjustv able hinge. looking in the direction of the arrow u Hung. Lpartsbeingbrokenforciaritn Fig. 8- is a fragmentary view of the stencil frame' and the material to be printed; and

Figs. 9, 10, 11 and 12 are diagrammatic illustrations of the tilting and lifting operation of the squeegee. 5

The frame I of the machine is rectangular and may be of wood or metal or any desired material and supported on legs 2 at appropriate locations.- At each end of one long side of the frame there is attached by any appropriate'means a 10 U-shaped angle iron 3, having the legs thereofv extending away from the frame, as shown in Fig. 7. The legs of each angle iron are provided with vertically aligned holes to slidingly accommodate the pins 4, and each pin 4 is provided 15 with a series of holes 5 for the reception of a stop pin 6, the latter being insertable in any hole to vertically position the pin 4 downwardly with respect to the frame I. Adjacent the top of each pin 4 there is journaled a transverse rock m shaft 1, supporting the frame 8 for swinging movement. The swinging frame 8 is rectangular and comprises U-shaped bars 9, III, bolted or riveted together, as shown in Fig. 1, spaced side `bars I-I attached at their ends within the U-shaped bar 9, one bar II lclosing the U and the other bar II being spaced therefrom and located on the side of the shaft 1 away from the bar II). Attached to the legs of the U-shaped vbar 9V are odset members I2 which locate the frame 8 with respect to the pins 4 and restrain the frame from endwise movement. `The stencil frame I3 depends from, and isdetachably secured to, the bars II, by the connection I3', as shown in Fig. 4. u

A spring I4 is attached at one end to the frame 8 on the opposite side of the rock shaft I from the stencil frame and the spring is attached at its other end to some convenient xed point, as the licor or leg 2. This spring normally holds the stencil frame and associated parts in elevated position. the frame being swung down to operative position by the foot of the operator stepping o'n a treadle I5, whichis connected to the frame 8 on the side of the rock shaft 'I opposite to the spring I4, by a link I6.

Both ends of the spreader carrier are the same and one end has been shown in detail, as in Fig. 4.

'I'he side bars `I I are grcoved on their inside 50 surfaces so that the grooves face each other and the bars Il are provided with laterally extending feet I'I yon which are slidingly supported blocks I8. The blocks I8 are attached to the ends oi' the right angled'legs I'II of a bar 20, spaces I9' 55 being provided between the ends of the legs |8 and the feet I1. The blocks I8 are guided by the grooves in the bars II on their sliding movement, but, if desired, these blocks may be replaced by rollers or other bearings.

Adjacent the ends of the bar 20 there are provided borings for the reception of bolts 2|. On the lower ends of these bolts there are provided bored blocks 22 for the reception of pivot pins 23 attached to the ends of the squeegee carrier 24. The upper ends of the bolts 2| extend through appropriate holes in a bridge member 25, and wing nuts 26 are screwed onto these bolt ends to support the bolts on the bridge member and thereby support the squeegee carrier. A compression spring 21 is located between the blocks 22 and the bar 20 to normally hold the squeegee 28 against the stencil 29, bearing in mind that the bar 20 is restrained against vertical movement by the attached blocks I8 in the grooves in the bars II, while the bolts 2| are slidable in the bores in the bar 20.

The squeegee 28 may be made of soft rubber or any other material desired, and is compressed between two slide plates 28 that are screwed into the carrier 24. By this means a larger or smaller squeegee may be secured to the carrier.

The ends of the bridge member 25 are bent over, as shown in Fig. 4, and are provided with pins 30 supporting wheels 3| for rotary motion.

'I'he wheels 3| run along on the top of the rails enable easy sliding of the carrier 24 in a vertical direction, while in contact with said interior sides.

On the tops of the rails there are located vseveral cam elements 34, longitudinally adjustable on the rails I I and detachably secured thereto by means of connections 35. lThe wheels 3| on the bridge member 25 ride on the rails and up cam surfaces 36 on the adjustable elements 34, at each end of the stroke of the squeegee carrier. In order to allow the bridge 25 to rise under influence of the cams, while the bar 20 remains at a constant level, slots 31 are provided in' the outer faces of the leg members I9, and the wheel journals 30 ride up and down in these slots, while maintaining a constant lateral relation of the wheels 3 I, bridge 25 and bar 20. i

From the foregoing description it will be clea that as the squeegee carrier is reciprocated on rails the springs 21 maintain thesqueegee pressed against the stencil and the dragof the latter on the squeegee carrier pivots it to the position shown in Fig. 9 when the carrier is traveled to the left, and to the position of Fig. 12 when returning to the right. One leg of the octagon cam 33 limits the degree of tilt of the squeegee, as clearly shown in these figures. As the carrier 24 approaches the end of its stroke in either direction, the wheels 3| ride up on the cam sur` faces 36, thus forcing the bridge 25, and with it, the bolts 2|, upwardly. Asthe bolts are connected to the carrier 24, the latter is also forced up against the action of springs 21, and due to the inclination of the octagon surfaces, the carrier 24 is slid upwardly into vertical-position, the

squeegee leaving the stencil. and thus thevdrag of the latter on theformer disappears. A slight further travel of the bar 20 and associated parts in the same direction carries the squeegee somewhat beyond the hea'ped up paint or other spreading material indicated at 38, the wheels 8| now riding on the horizontal part 36' of the cam 34.

Upon reversal of the travel of the carrier, the wheels 3| ride down the cam surfaces 36, the squeegee contacting the stencil which sets up a drag, and the squeegee is tilted in the Vopposite direction,-being limited in such tilt by the other leg of the octagon shaped cam 33. Thus, it is seen that the squeegee is traveled to spread the paint, or the like; automatically lifted over the heaped up paint,vand also automatically brought down,'tilted in the oppositedirection again contacting and spreading the paint, etc. in the reverse direction, without attention from the operator, so far as the squeegee is concerned.

The squeegee carrier is traveled by means of power, which is entirely located onl and supported by the swinging frame 8. A platform 48 is mounted in any desired manner on the bars 9, I0, as indicated in Fig. 1, and a motor 4| and a conventional reversing transmission 42 are supported on the platform. I'he motor and transmission are -connected by the usual pulleys and belt 43, and the output end of the transmission tively connected to spaced chains 48 through adjacent leg I8 of the bar 2|) by any desired connection 52, and the bottom runsof the chainsA travel below the legs I9 in the space I9'.

The transmission 42 is provided with a reversing operator consisting of the pinion 53, and

a rack 54. When the rack 54 is moved to either right or left from its central position, the transmission is thrown into neutral and the chains 48 stop, but when the rack is moved back to the central position by, for instance, la leftward motion of the rack 54, the power is again engaged and the carrier moves to the left. If the carrier is at the left end of the machine, as shown in Fig. 1, and the transmission is in neutral, a rightward pull on the rack will engage the power and the carrier will travel to the right. 'I'he rack may be operated in its sliding movement by the lever 55, pivoted to the frame 8 at 56, and connected at 51 through a lost motion connection to the rod 58 which is secured to the rack by a set screw. In order to automatically throw the y thought necessary to show them in the present' CaSe.

In the operation of the machine, the card ory other material to be printed is placed on the frame the screen 29 is secured by any con- 2,207,818 venient means to'the underside of the stencil frame Il, as shown in Fig. 8, and the latter is then secured to the rails II. The operator then steps'on the treadle I5, bringing the stencil and its frame down ,on the material to be'printed,

and the paint, etc. is placed in position on the top of the stencil. The operator then manipulates the lever as above explained to start the squeegee carrier along its path of travel which is horizontal, and due to the cam elements 3l, the squeegee will rise over or jump the paint, or the like, near the end of the travel, assume a vertical position, and be ready'to start back at any time desired, to reverse the spreading operation. In case a small size card is to be printed, the cams 34 and stop pins 59 are adjusted on their respective supports to the desired position corresponding to the size of the card and the squeegee will be traveled only over the desired length, thus saving time and paint, etc. It is therefore clear that this device will accommodate all sizes of material up to the capacity of the stencil frame easily and economically. 'Ihe springs 21 maintain the squeegee against the stencil in such a manner that the paint, etc. can only go in front of or under the squeegee.

The adjustable hinge at, l and 'I is provided so that any size of stencil frame or other device may be used. That is, ifa larger member than that shown at I3 in the drawings is to be used, the sliding pins l will automatically compensate for the consequent increased space between the frames 8 and I. Thus, practically any size of frame I3 can be used without manual adjustment of the frame 8. A further advantage ofi` the swinging frame is that all the work, and the stencil and its frame, may be placed in the machine from one side only, thus simplifying the operation.- i

Having thus described'our invention and the advantages thereof, we do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what we claim is:

l. In a device of the character described, means for spreading a printing substance on a surf/ace, means for traveling the spreading means over the surface, resilient means normally holding said spreading means in contact with-said surface, cam means for raising the spreading means from the surface at the end of its travel, and means to stop the traveling means at the point where the spreading means is in raised position, said rising means and said stopping means being adjustable along the path of travel of said spreading means, whereby the latter may be stopped and raised at any desirable point.

2. In a device of the class described, a printing substance spreader, a carrier therefor pivotally mounted in a traveling frame, means to limit the pivoting of the carrier, a surface over which the spreader carrier travels in contact therewith, the spreader carrier being tilted in the direction of travel by the friction created between the spreader and the surface, means to raise the spreader and the surface, means to raise and lower the carrier at a predetermined point, and

means yieldingly placing the carrier in vertical position when raised, whereby it is reversely tilted by contact with said surface upon being lowered and reversely traveled.

4. In a device of the class described, a spreader, means pivotally mounting said spreader, means to travel said mounting means with the spreader in contact with a surface, by which the spreader is tilted, means to yieldingly press the spreader against the surface, means to lift the spreader against the pressing means at a predetermined point, and means to place said spreader in a generallyv vertical position when lifted.

5. In a deviceof the class described, a spreader, means pivotally mounting said spreader, means to travel said mounting means with the spreader in contact vwith a surface, whereby the spreader is tilted, means to limit the tilt, means pressing the spreader downwardly, means to lift the spreader against the pressing means at a predetermined point, means to position the spreader in vertical position upon the lifting thereof, said surface tilting the spreader reversely` upon a reverse travel of the latter.

6. In a device of the class described, a spreader, means pivotally mounting said spreader on a horizontal axis intermediate its side edges, means to travel the mounting means horizontally, with one longitudinal edge of the spreader in contact with a surface, means at either side of the other longitudinal edge of the spreader to retain the spreader in vertical position when stationary, andlin tilted position under influence of the friction of the surface when traveling.

7. In a device of the class described, a sup--l port, a horizontal rock shaft located at one side of the support, and journaled in a vertically slidable support, a frame mounted on the rock shaft to be pivoted thereon, whereby the vertical position of the frame may be varied, a stencil frame detachably secured to the underside of the pivoted frame to be clamped between the latter and the first named support, a traveling printing substance spreader, and means to travel the same mounted on the pivoted frame to spread a substance on the stencil, the spreader and the means to travel it being on opposite sides of the rock shaft.

8. In a device of the class described, a support, a horizontal rock shaft located at one side of the support, and journaled in a vertically slidable support, a frame mounted on the rock shaft to be pivoted thereon, whereby the vertical position of the frame may be varied, a stencil frame detachably secured to the underside of the pivoted frame to be clamped between the latter and the first named support, a traveling printing substance spreader, means to travel the same mounted on the pivoted frame to spread a substance on the stencil, the spreader and the means to travel it being on opposite sides of the rock shaft, means to retain the pivoted frame with the stencil frame and spreader normally in raised position, and means to depress the same.

9. In a device of the class described, a reciprocable frame supporting a paint spreader, power-operated means to reciprocate said frame, adjustable stop means in the path of the frame to be engaged thereby at any desired point in the path of travel of the frame, the stop means being operatively connected to a. power interdicting device, whereby the reciprocating means is stopped upon engagement of the frame withthe stop, manually operat'able' means associated with the connection between the stop and the power mterdicting device, to reverse the operation of the power means, and adjustable cam means in the path of said spreader set to raise the same upon said engagement of the frame and the stop.

10. In a device of -the class described, a traveling carriage having a bridge-like element restricted to rectilinear movement, a member overlying said bridge: and capable of motion at an angle to the path of said-rectilinear movement, a movable support associated with said member and said bridge and having means to prevent mo ement of the same in one direction with respect to said member, a resilient element tending to urge said support in said direction,` and a spreader attached to said support.

11. In a devce of the class described, a traveling carriage having a bridge-like element restricted to rectilinear movement, a member overlying said bridge and capable of motion at an kangle to the path of said rectilinear movement, a movable support associated with said member and said bridge and having means to prevent movement of the same in one direction with respect to said member, a resilient element tending to urge said support in said direction, a spreader attached to said support, and means in the path of said member to move the same againstthe action of the resilient element, with respect to said bridge, thus also moving said spreader.

12. In a device of the class described, vthe combination of a traveling carriage having a transverse, support, a member above said support and same upwardly against said resilient action,thus

raising the spreader.

13. In a device of the class described, the combination of a traveling carriage having a transverse support, a m\ mber above said support and mounted for vert cal movement with' respect thereto, an elementA depending from said member and resiliently"urged downwardly, and a 'spreader attached to said element; with a'. cam means in the path of said member, adapted to urge the same upwardly against said resilient action, thus raising the spreader, said cam means being adjustable to any desired point in the path of the member.

14. In a device of the class described, a carriage, means to reciprocate said carriage, a member connected to said carriage and mounted for movement with respect thereto, an element slidsaid carriage against the action of said resilient means, and cooperating guide means on said carriage and said member to restrict the latter to a movement at an angle to the path of reciprocation of the carriage.

15. In a device of the class described, a spreader, means pivotally mounting said spreader, means to travel said mounting frame, resilient means urging said spreader with respect to saidv mounting means, positive means to urge'said spreader in the opposite direction at a predetermined point in the travel of said mounting means, and cam means to place said spreader in desired relation to said mounting means upon action of said positive means, said cam means comprising a generally U-shaped element having slanting surfaces on the inner sides of its legs, between which a portion of saidspreader is located.

ERNEST E. PERRY. FRANK A; CAMERON.

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