US2063479A - Sheet feeding mechanism - Google Patents

Description

Dec. 8, 1936. F. R. BELLUCHE SHEET FEEDING MECHANISM Filed NOV. 18, 1935 2 Sheets-Sheet 1 50: T/ON PuMP ai'wmm Fran/ .75 BMW/7F Patented a, 8, 1936 UNITED STATES PATENT OFFICE This invention relates to improvements in sheet feeding mechanism and refers particularly to feeders for printing machinery.

As is well known to those conversant with the printing art, an essential element of all sheet feeding equipment is some means for detecting and preventing the passage of imperfect sheets to the machine being fed. The imperfection to be particularly guarded against is the passage of more than one sheet at a time or a folded or doubled sheet. The detection of such objectionable sheets heretofore has been effected by means of a calipering mechanism, such as illustrated in the copending application of Elmer W. Belluche and Frank R. Belluche, Serial No. 703,370,

filed December 21st, 1933.

Briefly, this calipering mechanism consisted of a driven under roll and a pivoted segment mounted above it and adjusted so as to pass only a single sheet. When more than one sheet at a time was fed or when a sheet was doubled over, the added thickness swung the segment on its pivotal support and the movement so generated actuated a trip mechanism to stop the machine. As is evident this mechanism entailed a large number of parts, required lubrication of its many moving elements, necessitated careful adjustment for difierent paper thicknesses, and in addition required considerable space.

Another very serious disadvantage of this calipering mechanism, was the fact that any small imperfection in the paper which increasedits thickness would trip the machine, and on color printing where the printed surface is 35 sprayed withwax to prevent ofiset, the wax would build up on the caliper parts and thus destroy the adjustment.

With the above and other objections to existing forms of sheet detecting mechanisms in 40 mind, the present invention has as one of its objects to provide an improved and simplified detecting means and simple instrumentalities controlled thereby for stopping the machine upon the passage of a sheet of multiple thick- 45 ness.

With a view toward simplicity, it is another object of this invention to provide detecting meansin which the entire mechanism is pneumatically actuated and in which the heretofore With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claims,- it beingv understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawings illustrate two complete examples of the physical embodiment of the. invention constructed according to the best modes so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a longitudinal section view through a portion of a sheet feeder for printing machinery illustrating the application of this invention thereto; I

Figure 2 is a section view through Figure 1 on the plane of the line 22;

Figure 3 is an enlarged detail view to illustrate how the passage of more than one sheet at a time initiates the functioning of the trip mechanism; and

Figure 4 is a view similarto Figure 2 of a slightly modified embodiment of the invention.

Referring now more particularly to the accompanying drawings in which like numerals indicate like parts throughout the several views, the numeral 5 designates a source of sheet material, which in the present instance, is shown as a pile of sheetsloaded on the platform of a pile type of feeder. It is to be understood, however, that the invention is not in anywise dependent upon the nature of the source of sheet material.

Individual sheets are lifted from the top of the pile 5 by any suitable feed off mechanism, shown in the present instance as a suction cup 6 carried by a tubular swinging arm I; For a detailed disclosure of the feed ofi? mechanism shown, reference is made to the copending application hereinbefore referred to.

The feed. off mechanism lifts the individual sheets off the pile 5 and deposits them onto an endless conveyer 8 comprising a plurality of tapes trained about pulleys or rolls, only one of which, 9, is shown. As the leading edge portion of the sheet is deposited onto the conveyer 8 and released by the suction'cups 6, a drop roll 10 descends and coacts with the roll 9 to complete the disposition of the sheet onto the conveyer 8. The conveyer 8 advances the sheets deposited thereon to the press or other machine being fed.

As will be readily appreciated, in the actual installation, the feed oif mechanism incorporates two or more suction cups 6, and a plurality of drop rolls ill at spaced intervals alongthe length of the roll 9 are provided. The mechanism for raising and lowering the drop roll and for driving the conveyer 8 forms no part of this invention. Hence, it has not been shown.

As long as the sheets being advanced by the conveyer 8 are perfect, that is, are not of multiple thickness or folded over, the feeder mechanism operates uninterruptediy. However, upon the disposition of a doubled or multiple thickness sheet onto the conveyer 8, it is essential that the entire machine be instantly stopped to preclude the passage of such imperfect sheet to the press. To this end, two vertically spaced and opposed suction shoes II and [2 are arranged respectively above and beneath the path of the sheets defined by the upper stretch of the conveyor 8 at each side edge of the path of sheets. By duplicating the suction shoes at both sides of the machine, imperfections existing only at one side edge of the sheets will initiate the interruption of the machine, which is desirable.

The two suction shoes, which together comprise one detecting unit, at each side of the machine are connected with a common source of suction, but inasmuch as each detecting unit must function independently of the other, it is essential that two separate sources of suction be provided, or, as will be hereinafter more fully pointed out, a single source so arranged as to provide individual functioning of the two detecting units.

Any desired manner of connecting the suction ports with a source of suction may be employed, but for purposes of illustration, the shoes II and i2 may be mounted on tubes i3 and, I4 extending transversely across the machine, and respectively above and beneath the defined path of the sheets. At their centers, these tubes have plugs l5. Consequently, while the ports. I 6 and II of the suction shoes II and I2, respectively, are communi cated with the interiors of their respective tubes l3 and it, those of one unit are not connected with those of the other unit.

The opposite ends of the tubes l8 and it are fixed in suction heads l8 and I! in communication with the hollow interiors thereof. The suction head I8 is connected by means of a duct 28 with any suitable source of suction, such as a pump 2|, and the suction head I9 is connected through a duct 22 with a similar suction source 28. Both suction heads l8 and I! are also communicated with the interior of diaphragm chambers 24 and 25, respectively, (see Figure 3) so that the effect of suction created by the pumps at all times acts upon the diaphragms 26 in these chambers.

As long as the ports l6 and I! of the suction shoes II and I2, respectively, are open, the negative pressure in the suction heads and acting'on the diaphragms is insufficient to move the same from their normal positions at which they are held by springs 21 encircling stems 28 fixed to the v diaphragms. However, upon sealing of the ports l8 and H, the negative pressure within the suction heads builds up and acts upon the diaphragms causing the same to 'move their stems 28 against the force of their springs 21. This motion in response to an increase in suction within the suction heads may be utilized to actuate any suitable mechanism.

when the invention is applied to the feeder of a printing press, as here shown, the response of the diaphragms to increased suction is utilized to stop the entire machine. This is done through instrmnentalities including levers 29 flxed to a shaft 30. There are two such levers 29 and their free ends are engaged by heads 3! on the diaphragm stems 28 so that when either diaphragm responds, the shaft 30 is oscillated a sufllcient number of degrees to effect the functioning of the instrumentalities for stopping the machine.

For a complete disclosure of the manner in which the rocking of the shaft 30 stops the machine, reference may be had to the aforesaid copending application.

From the foregoing description, it will be readily apparent that upon the passage of a double sheet or a'sheet folded over only at one side edge, between the suction shoes ll and 12, the force of suction will seize the two sheets as shown in Figure 3 thus sealing the suction ports and permitting 'the negative pressure within the associated suction head to build up and cause the response of its associated diaphragm 28. Inasmuch as the suction is equal at both ports, when a single sheet passes therebetween, it is acted upon equally by the suction from both ports so that it floats" and is not drawn to one or the other port. It is, of course, to be appreciated that the normal path of the sheets is equidistant between the two ports.

In the embodiment of the invention so far described, an individual suction source is utilized for each pair of ports. It is possible, however, to

.employ a single source, and in Figure 4 one manner of using a single source of suction is illustrated.

Ashere shown, both suction heads I8 and I! are connected with a single suction pump 33 through separate'pipe lines 34 and 35, respectively, in which normally closed valves 36 and 31 are interposed. The valves 36 and 31 are adapted to be opened by cams 38 and 39, respectively, oppositely arranged on a driven shaft 48. This arrangement of the cams insures that only one of the valves is open at a time allowing but one suction head to be connected with the suction source at a time, and the speed of the shaft 40 is so related to the speed of travel of the sheets, that the two pairs of suction shoes are intermittently connected with the source of suction several times during the passage of a single sheet.

In other words, as the sheet advances between the suction shoes, the pair at one side edge acts upon the sheet for a few inches of travel, and then for the next few inches of travel, the otherdetecting unit acts on the sheet. In'this manner, a single source of suction is effectively used.

From the foregoing description taken in connection with the accompanying drawings, it will be readily apparent tothose skilled in the art to which this invention appertains, that this invention provides an exceedingly simple and practical mechanism for detecting and arresting the passage of doubled-over or multiple thickness sheets by a sheet feeder.

What I claim as my invention is:

ing sheet material along a defined path, instrumentalities for rendering the advancing mechanism inoperative, suction responsive means for actuating said instrumentalities, and control means for said suction responsive means including spaced suction ports arranged so as to have sheets-traveling along said defined path move flatwise therebetween whereby upon the passage of a multiple thickness sheet the effect of suction thereon seals the ports.

2. In combination with mechanism for advancing sheet material along a defined path, spaced 1. In combination with mechanism for advancsuction ports'arranged .on opposite sides of said such multiple thickness sheet including spaced suction ports arranged atopposite sides of said defined path so as to have sheets passed fiatwise therebetween and disposed sufilciently close to the path of sheets so as to have the outer layers of sheets of multiple thickness drawn thereto by the eifect of suction on said sheets.

4. In combination with mechanism for advancing sheet material along a defined path, mechanism to be actuated upon the passage of -a sheet of multiple thickness, suction means for actuating said mechanism, and means for controlling the functioning of the suction means so that the same acts only upon the passage of a sheet of multiple thickness comprising spaced suction ports arranged at opposite sides of said defined path so as to have sheets passed fiatwise therebetween with the space between the ports sufilciently close to the pathoi sheets as to enable suction thereat to act on a sheet of multiple thickness and seal the ports.

5. In combination with a conveyer ior advancing sheet material along a defined path with portions of said sheet material exposed on the bottom as well as the top, pneumatically operable motion generating means, means for creating a pressure differential at said motion generating means, and means controlled by the passage of sheets for altering the pressure difierential at said motion generating means comprising suction shoes having ports arranged above and beneath the defined path of the sheets and sumciently close to said defined path that suction at said ports acts upon the sheets passed therebetween.

6. In combination with a conveyer adapted to advance sheet material along a defined path, said conveyer permitting a portion of the sheets to be exposed on the bottom as well as the top, pneumatically operable motion generating means, means for creating a pressure difierential at said motion generating means, and means controlled by the passage of sheets for altering the pressure diiferential at said motion generating means com prising stationary spaced suction shoes having ports arranged above and beneath and equidistant from the defined path of the sheets so that an equal suction at the ports acts equally upon the sheets passed therebetween, and whereby upon the passage of a sheetflot multiple thickness, the efiect of suction on the sheets draws the outer layers thereof to the ports to seal the same.

7. In combination with mechanism for advancing sheet material along a defined path, a pair of suction shoes having ports arranged above and beneath and equidistant from said defined path so as to have sheet material passed fiatwise there between, pneumatically operable motion generating means, and common means for creating a bal anced suction at the ports of said suction shoes and for creating a pressure differential at said motion generating means, said ports and the motion generating means being so related that upon sealing of the ports as by the outer layers of a multiple thickness sheet passed therebetween the pressure difierential at the motion generating means is altered to effect its response.

8. In combination with a conveyer to carry sheets along a defined path, pneumatically operable motion generating means, means for creating a. pressure difierential at said motion generating means, and means controlled by the passage of sheets for altering the pressure difierential at the motion generating means, comprising spaced supports extending transversely across the path of the sheets, suction shoes carried by said supports and having ports opening above and beneath the path of sheets, and means for communicating the interiors of the suction shoes with the means for creating the pressure difierential so that upon sealing of the ports in the suction shoes the pressure diflerential at the motion generating means is altered to effect response thereof.

9. In combination with mechanism for advancing sheet material along a defined path, instrumentalities for rendering the advancing mechanism inoperative, pneumatically operable motion generating means at each side of the defined path of the sheet material for actuating said instrumentalities, means for creating an independent pressure differential at each of said motion generating means, and means controlled by the passage of sheets for altering v the pressure diiferentials at said motion generating means, comprising two transversely spaced pairs of suction shoes having ports arranged above and beneath the defined path of the sheets so that the passage of a sheet having a multiple thickness at only one side edge by having its outer layers drawn to and sealing the adjacent suction ports the pressure difierential at the motion generating means is altered to eifect response thereof.

10. In combination with mechanism for advancing sheet material along a defined path, pneumatically operable motion generating means, means for creating a pressure differential at said motion generating means, independent pneumatic detector units at opposite side edges of the path of sheets to coact with the sheets for controlling the pressure differential at the motion generating means, and means for rendering said detector units alternately operable so that they act on a sheet alternately.

11. In combination with. mechanism for advancing sheet material along a defined path, instrumentalities to be actuated upon the passage of a sheet having a multiple thickness either throughout its entire 'area or only at one side edge portion, pneumatically operable motion generating means for actuating said. instrumentalities, separate detector units at each side edge of the path of sheets each comprising a pair of suction shoes having ports disposed above and beneath the path of sheets so that the side edge portions of the sheets pass fiatwise therebetween, a single suction source for creating a pressure differentialmeans for alternately connecting the single suction source with the detector units so that said detector units are alternately operable.

FRANK R. BELLUCHE.

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