US 2146945 A
Description (OCR text may contain errors)
Feb. 14, 1939. I H. EHRIG ETAL 2,146,945
SHEET FEEDER Filed April 26, 19:57 3 Sheets-Sheet 1 Feb. 14, 1939. H EHRI L 2,146,945
SHEET FEEDER F iled April 26, 1957 6 Sheets-Sheet 2 1939- H. EHRIG El AL 2,146,945
SHEET FEEDER Filed April 26, 1957 5 Sheets-Sheet 3 dffomey Patented Feb. 14, 1939 PATENT OFFICE SHEET FEEDER Hans Ehrig and Ulrich Keilhauer, Leipzig,
rmany Application April 26, 193%, Serial No. 138,996
In Germany July 31, 1936 4 Claims.
Our invention relates to improvements in multiple purpose sheet feeders for printing presses, ruling, folding and like machines as disclosed in our United States Patent 2,060,800, which are provided with two sets of grippers, a primary and a secondary one, cooperatively arranged at the front end of the pile of sheets, the grippers of the primary set being adapted to engage the sheets from above and beingprovided with means for being'tilted and moved in a closed cycle of movements designated c c2 (Fig. '3), so as toseparate, lift and advance the sheets in the feeding direction, while the grippers of the secondary set are adapted to subsequentlyengage the sheets from underneath and being provided with means for laterally stretching the sheets and for being moved in a closed cycle of movements designated e-e2 (Fig. 3), so as to further advance and deliverthe sheets toa conveying mechanism.
In the embodiment ofthe inventiondisclosed in our United States Patent 2,060,800 intentionally only two grippers l0, lrepresenting the primary setare provided, which are arranged at a small distance from the central plane of symmetry vertically intersecting the feeder structure, so as to seize the sheets S exclusively in their middle section (Fig. 4) while the secondary set of grippers comprises two groups 20, 2|, 22 and 20', 2|, 22', which are arranged at both sides of the feeder and outside the primary set,
the object being to enable both sets of grippers to be moved by their actuating means (I I, 21) independently of each other, namely to freely pass each other, while moving in said closed ,cycles of movement 0-02 and e-e2 virtually intersecting each other at point i and three other points, as seen in Figs. 1 and 3.
Extensive practical experiments have shown, that with our patented feeders--because of havin"; only two primary grippers l0, l0 in the middle section of the feeder structure-highly adhesive sheets, having a sticky or rather rough surface, or being of a coarse, felty texture can not be separated from the pile in a positive and reliable manner, at least not at the desired high rate of speed exceeding 5000 sheets per hour.
Another drawback connected with the former consists therein, that it is impossible to separate and feed two sheets simultaneously, namely the upper sheets of two piles in juxtaposed position to each other, because each of said sheets'is grasped by the respective gripper l0, l0 only at one corner, and because-by reason of their inertia and adhesion to their mates underneaththe sheets in transit areangularly' displaced on being separated and advanced.
This invention of ours aims at overcoming the said drawbacks, namely to so re-design our patented feeder, that even sheets of a highly adhesive and obstinate nature, including card board and tissue paper, and of the largest sizes used in trade, can be safely separated in a trouble free manner and at-a high rate of speed.
In connection therewith the invention aims at providing structurally improved feeders of the type concerned for sheets of medium and smaller sizes, which can be quickly resetfor sheets of different width, this being an important factor in job printing, where often sheets of different medium and small-sizes are to be printed in small issues but in speedy succession.
A special feature of the smaller feeders re-designed according to this invention consists in the 1 provision of an auxiliary sheet lifting mechanism cooperatively associated with the secondary set of grippers, which insures the proper transfer even of sheets of the very smallest sizes used in practice to the sheet conveying mechanism of the feeder in correctly overlapped condition, namely in cases where the feeder is set for staggered feed.
Another likewise important feature of the improved feeder consists therein, that two sheets even of different nature, for instance of differentthickness-can be jointly separated from two piles of different height, arranged side by side, a peculiar printing job, which for instance occurs in printing simultaneously and consecutively numberingin one and the same machine two forms, which both bear the same number, on stout paper, and the other one, intended to serve later on as carbon copy, on tissue paper.
. The nature and scope of the invention are briefly outlined in the appended claims and will be more fully understood from the following specification taken together with the accompanying drawings, in which pairs of forms for custom oflice use, one of the Figs. 1 and 2 diagrammatically show in side and front elevation a sheet-feeder re-designed according to this invention for feeding sheets of the largest sizes used in the trade;
.Fig. 3 shows amodified arrangement of the innermost grippers of the secondary set;
Figs. 4-5 diagrammatically show in side and front elevation a structurally modified feeder re-designed for feeding sheets of medium size;
Figs. 6-7. diagrammatically show another structurally modified feeder re-designed for feeding sheets of small sizes;
Figs. 7a, 7b, 7c are side elevations showing auxiliary sheet lifting mechanism associated with the secondary grippers for feeding sheets of .the very smallest sizes in correctly overlapped relation to each other;
- Figs. 8-9 are a front and side elevation-showing by way of an example a feeder re-designed according to this invention, the tilting mechanism of which is mechanically operated instead of being suction operated as in our master patent;
Figs. 10-11 are a front and side elevation showing by way of an example an improved feeder, the tilting mechanism of which is suction operated;
Fig, 12-is a front elevation showing an improved feeder for feeding sheets of the largest sizes, which is adapted to feed also two sheets of different thickness simultaneously.
In contradistinction to the specific arrangement of the grippers shown in our United States Patent 2,060,800, and referred to more in detail in the preamble of this specification, the grippers of both sets including the primary set are-acprimary and secondary set has an actuating mechanism of its own, to the levers II I and I2! of which the grippers are attached; as seen in Fig. 2 the grippers and their actuating mechanism are arranged in staggered position, namely alternating between each other, except in the middle, where a pair of grippers H4, H5 of the secondary set is arranged between the innermost grippers T3,- T4 of the primary set with the object to enable two sheets being separated simultaneously from two piles arranged side by side.
The mechanism for actuating the various levers -I II and I2! carrying the individual grippers concerned resembles in all essential details that described in our earlier United States Patent 2,060,800 and comprises:
(1) A rotary shaft 10;
(2) A plurality of disks l4 keyed to said shaft 10 and being spaced in registration with the respective grippers;
(3). Slotted pitmans l2 linked to the levers Ill and slidingly guided by shaft 10 for being reciprocated; the, means for reciprocating said pitmans I2 include cams I! provided on said disks l4 and rollers l2 engaging said cams and being attached to the pitmans l2;
(4) Swing arms linked to the levers Ill and fulcrumed at 3a; pins l3 laterally projecting from said arms l3 are provided which engage covered cams (not shown) formed in said disks I4 for swinging said arms l3 up and down (5) Swing arms 28 fulcrumed at 3a and linked to the levers I21; the latter are provided with pins 21 laterally projecting therefrom and engaging covered cams (not shown), which are formed in said disks l4.
Each of\ the grippers concerned is provided with a valve or cock, indicated in the drawings at A, A2, and with a rubber hose for being indi vidually connected with or disconnected from a common source of suction air, which operates the grippers in the usual way through an air control mechanisminot shown but known perse in the trade.
'As seenin l 'lg. 3 the innermost gripp rs H4, H0
of the secondary set may be both attached to advantage to one single lever I21 provided with a forked upper end 45 with the object of actuating both grippers in a more economical and simple manner-viz. by one single actuating mechanism instead of two.
Various other changes and modifications may be conveniently made in the structural details of feeders of the improved design shown and described, without substantially departing from the spirit and the salient ideas of this invention:
With the embodiment of the invention, shown in Figs. 4 and 5 and designed for printing presses of medium size, the grippers of the primary set are arranged in two groups T20 and T20, symmetrically distributed over two carrier rods D,
,D2, which are coaxially arranged to each other and are fixed in cantilever fashion at their outer ends to the levers 2H and 2 I2 of actuating mechanism of the type described with reference to Figs. 1 and 2; the carrier rods D, D2 are spaced from each other at their inner ends so as to allow the lever 221 of another actuating mechanism to freely pass therethrough, which is arranged in the central plane of symmetry VV of the feeder, and to the carrier rod D3 of which the grippers H20, H20 of the, secondary set are attached in two groups and in symmetric disposition.
With the embodiment of the invention shown in Figs. 6 and 7 and designed for printing presses of the smallest sizes used in the trade for job printing, the grippers T30 of the primary set are secured to a carrier rod D5, which is attached in cantilever fashion at one end to the lever 3| I of an actuating mechanism of the type described with reference to Figs. 1 and 2, while the grippers H30 of the secondary set are mounted in a disposition reciprocal to that of the primary set on a carrier rod D1 attached at its outer end to the lever 321 of another actuating mechanism of the type described with reference to Figs. 1 and 2.
All the feeders described with reference to Figs. 1-7 can be quickly reset for sheets of different width by opening or closing the respective suction air cocks A, A2 of those grippers, which according to their position are to be used or not to be used for the respective job, and (or) by slightly displacing the outermost grippers on their carrier rods in lateral direction.
It will be noted from Figs. 6 and 7, that for feeders of the smallest sizes only two actuating mechanism namely one on each side of the feeder are required as against three in Figs. 4 and 5 namely 'one in the middle and one on each side, and still more with the feedersof the larger sizes, shown in Figs. 1, 2, 12 wherein each of the respective grippers has anindividual actuating mechanism of its own.
In Fig. 12 a feeder designed for printing pr es of the larger sizes is shown, which is provided a manner known from sheet feeders of 0th types with two separate platforms S, S2 arranged side by side, and having individual elevating mechanism W, W2 .of their own, which are ca pable of adjustment as to their rate of elevating by adjusting means known and not shown.
All the feeders re-designed according to this invention may be conveniently provided with a sheet conveyor of the double geared type described in our earlier United States Patent 2,060,800 and adapted to workat the operator's option at two'difierentrates oi -speed,- namely soas to feed the sheets either singly and in spaced relation to one another or Jointly in the form of a row of sheets in staggered relation to and overlapping one another.
Of said conveying mechanism which forms no part of this invention in Figs. 1, 4 and 8 only the conveying rollers 34-, 35, pulleys 33 and tapes 3| are shown.
All the feeders re-deslgned according tothis invention may be conveniently fitted with double platforms S, S2 having individual elevating 10 mechanism so as to afford the separation and feeding of two sheets 'of unequal thickness simultaneously for oddprinting jobs of the type indicated hereinbefore by way of an example.
Y It has been found, that-undercertain working conditions, where a. feeder of the design shown in Figs. 4-7 is set for staggered feed, namely with the sheets approaching the press overlapping each other, so that the rear edge of the first sheet lies on top of, the front edge of sheet number two, as seen in Figs."7a7c,- and where small size and thin sheets of highly flexible nature are under treatment,fthe rear portion of the sheet number three in transit to the conveying rollers 34, 35 is apt to drop and bend down, as indicated at 31' in dot and dash lines in Fig. 7a,
and with the result, that the front edge of sheet v number four would be misplaced-namely over the rear edge of sheet number three, instead of underneath: This wouldbe fatal, since every first sheet arriving at the front lay marks must not be frictionally engaged by the secondary sheet, but must be free to be pulled laterally into contact with the side lay marks. .In order to ensure under all working conditions and with all kinds of sheets, including smalland thin sheets, their properpositioning with regard to the overlapping edges referred to above,
an auxiliary sheet lifting mechanism has been provided according to this invention for coopera 40 -tion with the feed rollers 34, 35, namely for positively up-lifting the rear portion of the sheets as indicated by an arrow in Fig. 7a:
In the embodiment of the invention shownin Fig. 7a said sheet lifting mechanism comprises a,
perforated tube I01, connected with a-source of compressed air, (not shown) through which blast air is periodically blown so as to hit the rear portion of the sheets in transit and lift the latter. In the embodiment of the invention shown in Big-7b the auxiliary sheet lifting mechanism concerned comprises a plurality of guide rods downwardly bent at their rear ends I00, and attached preferably tothe rocking frame, which carries the rollers 34.
' In the embodiment of the invention shown in Fig. 7c said auxiliary sheet lifting mechanism comprises suction operated grippers I09 attached to an'actuating mechanism, which esentially consists of a double armed lever III, cooperative- 1:7 associated by means of a springwith a stavention' mayalso be provided with suction operated tilting mechanism of the same design, 'more especially in cases, where the feeder is expected to work often and for long working periods at high rates ef-speed,
An advantageous disposition of whereintwo air cylinders 2", iii having-pistons, piston rods 2", 2" and-levers ila, 21a are arranged at both sides'of the feeder structure for tilting the primary grippers T23, T23 is shown inl 'lgaloandllbywayofanexample. 5
.In cases, where high speed is not the predominant consideration positively acting tilting mechanismoftheusualdesismas shown by wayofan example in Figs. 8 and 9, may be convenientlyprovided, comprising cam and lever'motions K, 10 223, which are cooperatively interconnected by means ofrrocking arms 2l2, Iii, pin and slot gears 2Il, 2l3' and connecting rods 2", 2l3f with double armed levers 2|, II for tilting the primary rippers T2, T2". 15
Whatweclaimis: I 1. Sheetfeederofthetypehavingtwosetsof grippers, a primary and a secondary one, cooperatively arranged at the front end of the pile of sheets the grippers of the primary set being 20 adapted to engage the 'sheets from above, so as to separate, lift and advance the sheets in the feeding ,direction, while. the grippers of the secondary'set are adapted to subsequently engage the sheets from underneath, so as to further; 25 advance and deliver the sheets to conveying means,wherein the grippers of both sets are symmetrically distributed over the whole width if the feeder,the' grippers of the primary set being attached to carrier rods coaxially arranged and spaced from each'other at their inner ends, said carrier rodsbeing fixed in cantilever fashion at their outerends to the levers of actuating mechanisms arranged at both sides of the feeder structure, while the grippers of the secondary set are 35 tively arranged at the front end of the pile of sheets, the grippers of the primary set being adapted to engage the sheets from above, so as to separate, lift and advance the sheets in the 45 feeding direction, while the grippers of'the second- 'ary set are adaptedto subsequently engage the fashion to the lever of an actuating mechanism 55 provided at one side of the feeder, while the grippers of the secondary set are attached to a carrier rod fixed in cantilever fashion and in aposition opposite to that of the primary grippers to the lever of an actuating mechanism provided at the opposite side of the feeder structure.
3. Sheet feeder-for printing presses and like machinw having means for separating the sheets from the pile and means for conveying the sepa+ rated sheets to the printin press or like machine-said separating means comprising a plurality of primary grippers distributed over the v whole width of the feeder for engaging the sheets along their front edge from above, separating 70 .and advancing them in the feeding direction,
and a plurality of secondary grippers distributed over the whole width of the feeder'for subsequentk engagipg the sheets from underneath and deliveringthem to-the conveying'means,the 5 along their front edge from above separating and advancing them in the feeding direction, and a plurality of secondary grippers distributed over the whole width of the feeder for subsequently engaging the sheets from underneath and delivering them to the conveying means.
HANS EHRIG. v ULRICH KEILHAUER.