US 2914324 A
Description (OCR text may contain errors)
Nov. 24,1959 w. D. BRAINARD 2,914,324
MAGNETIC SHEET FEEDER Filed June 6, 1956 4 Sheets-Sheet 1 l/VVENTOR. WILSON D. BRm/vmm arm ELM Arrokusx Nov. 24, 1959 I w. D; BRAINARD h I ,9
MAGNETIC SHEET FEEDER I Filed June e. 1956 I sheets-sheet 2 f 3 I E I mwsA/rop W11. 60M 0. ERMA/4P0 Nov. 24, 1959 w. D. BRAINARD MAGNETIC SHEET FEEDER r m y E t T N e m 0 54 r w WM m m 0 w 4 M a ls M Y 8 g QM.
Filed June 6, 1956 Nov. 24, 19 59 ,W. D. BRAINARD 2,914,324
MAGNETIC SHEETYFEEDIER 4 Sheets Sheet 4 Filed June 6, 1956 mm Mm a I/Y VE/YTOR. WILSON D. Rpm/V400 ATTOR/YEK' Unitd States MAGNETIC SHEET FEEDER Wilson D. Brainard, Franklin Square, N.Y., assignor of fifty percent to Owen Brainard, Des Moines, Iowa Application .iune 6, 1956, Serial No. 589,803
8 Claims. (Cl. 27184) My invention relates to improvements in silk screen machines.
The instant invention contemplates a silk screen ma chine that will materially increase the speed and efficiency of operation as compared to present machines of a like nature. As will later appear I have preferably shown it as working semi-automatically but it will be understood that full automatic operation can be obtained without departing from the principle thereof.
Another object of this invention is to provide in a silk screen machine a novel means for transferring paper or other material to be printed, from one position to another.
Still another object inhering herein is the provision in a silk screen machine of simultaneously effecting the movement of three separate sheets of paper, namely, the sheet on the drying plate, the sheet on the printing surface and a sheet from the supply stack.
Another important object of this invention is to provide a magnetic paper gripping means for use with a machine of the above class.
Other objects and advantages of this invention reside in the details of construction and correlation of the various parts and will be apparent as the description proceeds.
This invention consists of novel parts and combination of parts to be hereinafter described whereby the objects set forth are attained, as pointed out in the claims, and illustrated in the accompanying drawings, in which:
Fig. 1 is a perspective view showing a preferred form of my invention,
Fig. 2 is an enlarged top view of this machine showing theframed screen in printing position,
Fig. 3 is an enlarged side view of the magnetic paper gripper taken from the line 33 of Fig. 2 and showing it in closed contact with a sheet of paper,
Fig. 4 is a top view similar to Fig. 2 but showing the framed screen moved away from its printing position,
Fig. 5 isa side view similar to Fig. 3 but showing the open position of the gripper when moved correspondingly to the position of the framed screen in Fig. 4.
Fig. 6 is an enlarged perspective view of a flap valve used with the air hose in this machine.
Fig. 7 is a fragmentary side view of one of the tracks taken on the line 7-7 of Fig. 2 and showing the lower position of the drying plate,
Fig. 8 is a view similar to Fig. 7 but showing the raised or elevated position of the drying plate, and,
Fig. 9 is an enlargedfragmentary elevational view partly in section taken on the line 99 of Fig. 4 and showing the paper supply table and elevating means therefor.
Referring to the drawings a box-like supporting base 10 houses a suitable motor and pump (not shown) for use in providing suction as will later appear. A pair of parallel side boards 12 and 14 forming a part of base 1d are mounted to respective opposite sides thereof (Fig. 1) andproject from opposite ends thereof as shown. End
Patented Nov. 24, 1959 braces 16 connect the side boards 12 and 14 at each end and carry the respective tracks 18 and 20 that are substantially co-extensive in length with each side board and adjacent the same. A cross member 22 rests on top of rails 18 and 20 between the right ends of boards 12 and 14 as viewed in Fig. 1, which end for purposes of clarity will be referred to as the rear 24 to distinguish it from the left side of Fig. 1 which I shall call the front or forward end 26.
A printing surface or board or paper supporting platform 28 (Fig. 1) is mounted between boards 12 and '14 and approximately midway between the front 26 and rear 24 thereof and is provided with a beveled notch 36 toward the front end 26. Between the rear portions 'of side boards 12 and 14 (Fig. 9) a horizontal base 32 is placed for supporting a supply of paper 34 and is pro-' vided with depending Wedge shaped sides 36 which are progressively narrower in depth toward end 24 as shown. Sides 36 are slidably rested on respective wedge sides 38 of a U-shaped frame 4i having its closed end extending between boards 12 and 14 at end 24. Frame 40 is mounted so as to be slidable towards end 26 for raising base 32 as will be later explained in detail. A shaft 42 is mounted transversely of boards 12 and 14 just forwardly of base 32 and carries a cable 44 wound thereon and extending to a point of attachment 46 on frame 40 at end 24. Shaft 42 carries a ratchet wheel 48 on one end near side board 14 and a resilient pawl 50 engages wheel 48 as shown.
At the forward end 26 of this machine I have mounted a drying unit indicated generally at 52. This comprises .an electric heating element 54 carried on a downwardly inclined support 56 firmly aiiixed to the front side of base 10. At the lower end of support 56 is an upnstanding baffie or stop 58 and in endwise alignment with and as an extension of the support 56 there is placed an open top receiving tray member 60. A drying board or plate 62 having good thermal conducting ability and thus preferably made of aluminum lies over the heating element 54 in substantially a parallel plane with support 56 and is hingedly secured as at 64 to the respective boards 12 and 14. Rigidly connected to plate 62 at its hinge point near board 14 is a bar or lever 66 that is disposed adjacent and substantially parallel to track 18. Lever 66 extends towards end 24 of this machine and is provided on its free end with the vertical shoulder 68 followed by the inclined surface 749. This arrangement as will later be described more in detail is to provide a tilting of lever 66 and plate 62 about hinge 64 as a pivot point whereby plate 62 is raised and lowered relative to the top of baffie 53. Suspended over the plate 62 and supported from the brace 16 is an infra red heat lamp 71 which together with element 54 supplies heat simultaneously to both sides of plate 62.
A carriage or frame indicated generally at 72 (Figs. 2 and 4) is movably mounted on tracks 18 and 26. It is generally U-shaped having the sides 74 and 76 which carry wheels '78 at each end; a cross member 80 at one end positioned relative to the forward end 26 of this machine and a second cross member 32 substantially midway between the ends of sides 74 and 76 to provide carriage openings 34 and 86. A frame 88 containing a silk screen 96 is hinged to carriage frame side 74 so that it can be raised and lowered into opening 84 (Fig. 1). A spring means 92 connects screen frame 88 to the carriage side 74 so as to normally urge it to open or raised position. To the opposite side of screen frame 88 a cord or cable 94 extends over a pulley 96 mounted on sideboard 12 and carries a weight 98 on its free end which hangs suspended along side base 10.
A suction pickup foot 100 is mounted on crossbar 82 of the carriage so as to communicate with opening 84 'the bar member 110 which extends therefrom across the crossbar 82 and over opening 86 where it carries a roller 112 on its free end. Bar 110 also contains a counterbalance 114 and is hingedly connected as at 116 to an underlying bar 118 projecting into opening 86 from crossbar 82. Thus it will be seen that foot 100 has a certain range of vertical movement by rocking on point 116. On brace 22 at the rear end 24 of this machine, an arm 120 is mounted to extend toward roller 112 and in line therewith. The free end of arm 120 is inclined downwardly to form a ramp 122 so that as the carriage is moved toward end 24, roller 112 will ride up ramp 122 and lower .the suction foot 100.
With reference now more particularly to Figs. 3 and I will describe my magnetic paper gripping jaw assembly which is one of the important novel elements on this machine. As shown this gripper member or jaw assembly indicated generally at 124 is used for removing a sheet of paper 126 from the printing surface 28 for transfer to the drying plate 62 but it will be understood that a gripper of this type can also be used for transferring paper from stack 34 to the printing surface 28 instead of the suction foot 100 as will later appear. Gripper 124 is mounted to the central underside of cross member 80 of the carriage frame and comprises an elongated block 128 secured transversely of the longitudinal axis thereof. A steel plate 130 is secured to the bottom of block 128 so as to project into opening 84 and carries a claw point 132 on its free end. A second block 134 is hinged at 136 intermediate its ends to the lower forward end of block 128 relative to the forward end 26 of this machine. In this position it will be noted that block 134 projects beyond block 138 toward end 26 and a ramp like edge 138 is formed on the projecting edge thereof. The top of block 134 carries an aluminum plate 140 which projects rearwardly correspondingly with plate 130 and also has a claw point 142 positioned to register with point 132 on plate 130 at times in a gripping action. A permanent magnet 144 on block 134 is positioned to engage plate 130 by magnetic attraction in which position (Fig. 3) points 132 and 142 will be clamped together. Below plate 140 on block 134 is an inclined baffie 146 positioned to register with the beveled edge or notch 30 on the printing surface 28 as seen in Fig. 1. On cross brace 16 (Fig. 1) a trip roller 148 is placed which is engageable by the ramp 138 on block 134 so as to move block 134 on its hinge point 136 and break the magnetic connection between magnet 144 and plate 130 whereby points 132 and 142 are separated (Fig. 5).
In describing the operation of this machine reference is first made to Fig. 4 where the carriage is at its farthest point to the left or front 26. A sheet of paper 126 to be printed is positioned on the printing surface 28 and a supply of paper 34 is in position towards the rear 24 as described. The carriage is manually moved to the right or its rear position by grasping knob 150 on cross member 80 of the carriage during which several operations occur simultaneously. The silk screen 90 and frame 88 are moved to a position over paper 126 and the drag on cable 94 with weight 98 lowers the screen where the application of paint is manually performed in a well known manner. As the carriage is thus moved, baffle 146 on the gripper 124 rides up the beveled surface 30 of the printing board 28 (Fig. 3) which serves as a trip means for block 134 so that the magnet 144 attaches itself to plate 130 and jaws 132 and 142 clamp themselves on the edge of paper 126. At the same time roller 112 associated with the suction foot 100 will ride up the ramp 122 on arm 120 so as to bring the foot close enough to paper stack 34 to pick up the top sheet. A depending wedge member 152 from carriage side 74 (Figs. 7 and 8) will ride over shoulder 68 of lever 66 and drop down at the rear of the inclined surface 70. Wedge 152 is hinged so it can swing upwardly toward the front but as shown will remain vertical and rigid against any rearward movement. A pawl 154 on the rear of carriage member 74 will move to engage one of the teeth in ratchet wheel 48 (Fig. 9).
With the carriage now in position shown in Fig. 2 and with sheet 126 printed, the carriage is returned to its forward position as shown in Fig. 4. This also results in several simultaneous operations as follows. Gripper 124 withdraws sheet 126 from the printing board 28 until jaws 132 and 142 are separated by block 134 engaging the trip roller 148 (Fig. 5). Before jaws 132 and 142 release paper 126, however, wedge 152 (Fig. 8) engages surface 70 of lever 66 to rock said lever on pivot 64 and elevate drying plate 62 above the baffle 58. Thus any sheet on plate 62 for drying will slide ofl by gravity into tray 60. Consequently, plate 62 is free and as jaws 132 and 142 release paper 126, such paper drops onto the drying plate 62 which is now below the top of battle 58 so that such baflie serves as a stop to hold the paper on the drying plate. Side guides 156 may also be placed on plate 62 to retain the paper against lateral displacement. During this time, the suction foot has carried another sheet of paper from stack 34 to a position over the printing board 28 at which point the suction is released by the penetration of flap valve 104 with a pronged member 158 carried by the rear of carriage member 74. The effect of member 158 (Fig. 6) is to open valve to the atmosphere where foot 100 releases the paper. Pa per guides 160 and 162 and 164 (Figs. 2 and 4) are provided to assure accurate positioning of the sheet to be printed. These are adjustable in a well known manner. It is also pointed out that as the carriage is moved from its rearmost to forward position, pawl 154 (Fig. 9) will rotate ratchet wheel 48 one notch to correspondingly wind cable 44. This pulls the wedge 38 forwardly under wedge sides 36 to cam the paper supporting base 32 upwardly so as to keep the top of stack 34 within reach of the suction foot 100. However, due to the fact that foot 100 has approximately one half inch of vertical travel a substantial number of sheets, depending upon their thickness, can be picked up without anyelevation of the base 32. When wedge 38 has been drawn forward as far as possible, it can be manually returned to its starting position. It will also be noted that the screen frame 88 is elevated by spring 92 as the carriage is moved to its front position.
A back paper gauge 166 for stack 34 is placed on the paper base 32 (Figs. 2 and 4) and comprises a bar 168 positioned transversely of side boards 12 and 14. Knobs 170 and 172 on respective ends thereof have lower projections (not shown) which ride in the respective grooves 174 and 176. Bar 166 has a notch 178 to allow clearance of arm 120.
As the process of moving the carriage as described is repeated, it will be apparent on the return movement towards the front of this machine that three sheets of paper are being simultaneously processed. As such carriage movement is started, one sheet is on the drying plate 62, one is on the printing board'28 and one is on the stack 34. Due to the double heat exposure onthe drying unit 52, each sheet is quickly dried so as not to require separable stacking. Thus the carriage moves to the left as viewed in Fig. l, the sheet on the drying plate 62 is dropped into the tray 60, the sheet on the printing board is dropped onto the drying plate and a new sheet from stack 34 is dropped onto the printing board. Such an arrangement materially increases the amount of work that can be completed in a given time and saves a multitude of individual handling operations formerly required.
It is submitted that the invention shown and described is aptly suited to achieve the purposes intended and is characterized by a combination of highly useful and mutually cooperating elements that combine their respec tive and proportionate functions in accomplishing the objects sought to be obtained.
It, will be understood that the phraseology employed herein is for the purpose of description and not for limitation and that modifications and changes in the constructionand arrangement 'of this invention can be made withinitlie scope of what is claimed, without departing from the-spirit and purpose thereof. It, is thus intended to cover by the claims, any modified forms of structure or mechanical f equivalents which may be reasonably ineluded within their scope.
1. In a silk screen machine having a base and a carriage slidable thereon, an improved means for transferring paper from one position to another, comprising, a jaw assembly including a pair of jaw members on said carriage for gripping a sheet of paper, one jaw member movable relative to the other, a permanent magnet on said jaw assembly for holding said jaw members in paper gripping contact, means for breaking and reestablishing the magnetic attraction between said jaw members, said means comprising a pair of spaced trip members on said base, and said carriage movable to selectively place said jaw assembly in and out of contact with said trip members, one of which opens the jaw members against the magnetic attraction and the other of which closes the jaw members to reestablish the magnetic attraction.
2. In a silk screen machine having a base and a carriage slidable thereon, an improved means for transferring paper from one position to another, comprising, a first block secured to said carriage, a metal jaw member extending from one end of said block, a second block hingedly secured intermediate its end to the other end of said first block, a jaw member on said second block to register with the jaw member on the first, a permanent magnet on said second block engageable by magnetic attraction with said metal jaw member to move said jaw members into paper gripping contact, a trip roller on said base, and said carriage movable toward said trip roller so that said second block engages the same and rocks upon its hinge point whereby the magnetic attraction between said magnet and said metal jaw member is broken.
3. In a silk screen machine having a base and a carriage slidable thereon, an improved means for transferring paper from one position to another, comprising, a first block secured to said carriage, a metal jaw member extending from one end of said block, a second block hingedly secured intermediate its end to the other end of said first block, a jaw member on said second block to register with the jaw member on the first, a permanent magnet on said second block engageable by magnetic attraction with said metal jaw member to move said jaw members into paper gripping contact, first and second trip means respectively on said base in spaced relationship, said carriage slidable in one direction to engage said second block with one of said trip means whereby said second block is rocked in one direction on its hinge point to separate said jaw members by breaking the magnetic attraction therebetween, and said carriage slidable in another direction to engage said second block with the other trip means to rock said second block in the opposite direction to bring said magnet into contact with said metal jaw member whereby said jaw members are in gripping contact.
4. In a silk screen machine having a base and a carriage slidable thereon, an improved means for transferring paper from one position to another, comprising, a jaw assembly including a pair of jaws pivotally disposed on said carriage for movement toward and away from each other to respectively grip and release a sheet of paper,
one of said jaws being magnetically attractable, a magnet. means on the other jaw, means on said .base engageable with said jaw assembly to urge one jaw toward the other whereby said jaws are closed in paper gripping contact by said magnet means, a second means on said base engageable with said jaw assembly for urging one jaw away from the other to break the magnetic attraction, and the operation of the means for opening and closing said jaws being eifected by the movement of said carriage in respective opposite directions at times.
5. In a silk screen machine having a base, a printing board and a carriage slidable on said base over and away from said printing board, an improved means for removing a sheet of paper from said printing board, comprising, a pair of jaws pivotally disposed on said carriage for movement toward and away from each other to respectively grip and release a sheet of paper, one of said jaws being magnetically attractable, a magnet means on the other jaw, one edge of said printing board provided with a ramp-like notch, means on one jaw engageable with said notch when the carriage is moved toward the same for urging one jaw toward the other whereby said jaws will be clamped by said magnet about the edge of a sheet of paper on said printing board, the movement of the carriage away from said printing board causing said jaws to withdraw the paper therefrom, a trip means on said base, and one of the jaws engageable with said trip means when the paper is clear of said printing board to urge said jaw away from the other whereby the magnetic attraction is broken and the paper is released.
6. In a machine having a base, a carriage slidable thereon in two opposite directions respectively and a paper supporting platform, an improved means for transferring paper from said plat-form to a point of deposit, comprising a jaw assembly secured to and movable with said carriage, said jaw assembly including a first fixed jaw having a claw point and a second jaw having a claw point and pivotally attached to said first jaw so that said claws can be moved into and out of paper gripping contact with each other, a permanent magnet means associated with said jaws to hold said claws in gripping contact when said second jaw is within the field of magnetic attraction, said second jaw having spaced inclined surfaces, said platform having a ramp-like notch, said base having a roller, and said carriage movable between said notch and said roller to respectively engage said inclined surfaces therewith in order to rock said second jaw on its pivot point to selectively move said claw points toward and way from each other.
7. In a machine having a base and carriage slidable thereon, an improved means for transferring paper from one position to another, comprising a jaw assembly secured to and movable with said carriage, said jaw assembly including a pair of jaw members one of which is pivotable relative to the other so that they can be moved into and out of paper gripping contact, one of said jaw members having a metal portion and the other having a permanent magnet engageable with said metal portion within the field of magnetic attraction to hold said jaw members in gripping contact, said pivotable jaw member being freely movable relative to the other outside of the field of magnetic attraction, separate respective trip means at spaced points on said base engageable with said pivotable jaw member at respective opposite points thereon relative to its pivot point to move the same into and out of the field of magnetic attraction, and said engagement of said movable jaw member with said trip means effected by movement of said carriage.
8. In a machine having a base and a carriage slidable thereon, an improved means for transferring paper from one position to another, comprising a jaw assembly secured to and movable with said carriage, said jaw assembly including a pair of jaw members one of which is pivotable intermediate its ends so that it can be moved into and out of paper gripping contact with the other, a permanent magnetic means on said jaw assembly as the sOlc means for holding said jaw members in paper gripping contact, said pivotable jaw member being freely movable relative to the other outside of the field of magnetic attraction, and said carriage slidable between spaced fixed points on said base to abut said pivotable jaw member therewith whereby said jaw member is rocked upon its pivot point to selectively move said jaw member into and out of the field of magnetic attraction.
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