US3372924A

US3372924A - Vacuum sheet feeder

Info

Publication number: US3372924A
Application number: US513339A
Authority: US
Inventors: Ernest H Treff
Original assignee: FL Smithe Machine Co Inc
Current assignee: FL Smithe Machine Co Inc
Priority date: 1965-12-13
Filing date: 1965-12-13
Publication date: 1968-03-12
Anticipated expiration: 1985-03-12

Description

March 12, 1968 E. H.TREFF 3 372 2 VACUUM SHEET FEEDER Filed Dec. 15, 1965 2 Sheets-Sheet 1 T 72 INVENTOR fave-s7- A 72 5;;

ATTORNEYS v March 12, 1968 E. H. TREFF VACUUM SHEET FEEDER Filed Dec. 15, 1965 2 Sheets-$heet 2 ATTORNEYS United States Patent 3,372,924 VACUUM SHEET FEEDER Ernest H. Treif, Port Washington, N.Y., assignor to F. L.

Smiths Machine Co., Inc, New York, N.Y., a corporation of New York Filed Dec. 13, 1965, Ser. No. 513,339 6 Claims. (Cl. 271-25) ABSTRACT OF THE DISCLOSURE A hollow, rotary housing includes a movable wall por tion through which suction may be applied at timed intervals in order to grasp the leading blank in a stack and then deliver the blank to a conveyor.

The present invention relates to apparatus for transferring sheets from one location to another.

In particular, the invention relates to the transfer of fiexible strips or sheets which may be made of paper, for example, and which can be used for any desired purpose, such as envelope blanks. When dealing with sheets of the latter type, in many industrial applications, it is necessary to transfer the sheets from a given starting position to a given end position. The starting position may be, for example, at the end of a supply stack from which the sheets are to be transferred one by one to an end position where the sheets are delivered to a conveyor which continues the transportation of the sheets to locations where the sheets are further treated.

With apparatus of this general type it is necessary at the present time to use fairly complicated, expensive apparatus for removing the sheets one by one from their supply stack and delivering them one by one to the con veyor or the like. The conventional apparatus used for this purpose includes devices such as suction heads which initially must be moved into engagement with the end sheet of a stack, for example, while the suction is ap plied so as to hold the end sheet in engagement with the suction heads. Then through suitable cams, linkages, and the like, all of which are complex and expensive, it is necessary to displace the suction heads away from the stack so as to draw the end sheet away from the remaining sheets of the stack. Then the suction heads are moved to the location of a conveyor or the like, after which the suction heads are vented to atmosphere so as to release the sheets which can then be carried away by the conveyors. Not only is this conventional apparatus complicated and costly, in addition it requires a considerable amount of maintenance and occupies valuable space which could well be used for other purposes.

It is accordingly a primary object of the present inventionto provide a sheet-transfer apparatus capable of transferring a strip or a sheet from a given starting position to a given end position with a structure far simpler than anything which has heretofore been used for this purpose.

In particular, it is an object of the invention to provide a structure of this type which will not require the use of complex cams, linkages, and the like, in order to displace suction heads in the manner referred to above.

Yet another object of the present invention is to provide an exceedingly simple structure which will utilize the sheet which is being transferred as an automatic control element, so that the necessity of providing special. controls in the nature of cams and the like can be obviated;

In particular, it is an object of the invention to provide a structure which will respond automatically to pressure differentials for the purpose of bringing about the transfer of the sheet from a given starting position to a given end position.

The strips or sheets will be supplied by a supply means which will displace the sheets one after the other to a predetermined starting position from which the sheets are to be transferred to a predetermined end position, one after the other. At this end position is located at least part of a conveyor means which receives the sheets to convey them beyond the end position to locations where the sheets will be further treated.

The transferring device of the invention comprises a support means which has a hollow interior and carries a sheet-engaging member which is movable with respect to the support means between outer and inner positions relative thereto, this sheet-engaging member being formed with an opening passing therethrough and providing communication between the exterior and the hollow interior of the support means. The structure of the invention includes a moving means which moves the support means along a given path which will displace the sheet-engaging member into engagement with a sheet at the starting position. At this time a pressure-control means will tend to maintain the hollow interior of the support means at substantially less than atmospheric pressure, so that the covering of the opening of the sheet-engaging member by the sheet. itself will cut ofi communication between the hol- 10w interior of the support means and the outer atmosphere, thus providing in a fully automatic manner and by way of the sheet itself a pressure differential which will displace the sheet-engaging member from its outer position to its inner position. This displacement will pull the sheet away from the end of the stack provided by the supply means.

The moving means continues the movement of the support means along a predetermined path which will locate the sheet, still held against the sheet-engaging member by the suction applied. through the hollow interior of the supportmeans and the opening of the sheet-engaging member, at, the end position where the sheet will be delivered to the conveyor means. When this part of the operation has been reached, the hollow interior of the support means is placed by the pressure-control means in communication with the outer atmosphere, thus releasing the sheet to be carried along by the conveyor means while the moving means returns the parts to the position where the next sheet can be engaged by the sheet-engaging member so as to have the above operations repeated.

It is to be noted that need may arise to effectttr'ansfer of excessively wide sheets or in other cases, narrow strips of flexible material, such as paper. In the first instance, a plurality of the inventive sheet-engaging members may be arranged to operate concurrently on a single sheet, whereas in the. case of a narrow strip to be transferred, a single sheet-engaging member may be sufiicient. The sheet or strip supply means, in the above-noted various applications, is adapted to the particular requirements of the size of the flexible material to be handled.

The invention will become more readily apparent from the following description of the preferred embodiment thereof, illustrated, by way of example, in the accompanying drawings which form part of the application and in which:

FIG. 1 is a fragmentary top plan view of one possible embodiment of an apparatus embodying principles of the present invention;

FIG. 2 isa partly sectional side elevation of the struc" ture of FIG. 1, taken alongline 2"-2 of FIG. 1 in the direction of the arrows;

' tion of the arrows and showing the parts in FIG. 3 is an exploded perspective illustration of the hollow support means, sheet-engaging member carried thereby, and pressure-control means;

FIG. 4 is a sectional elevation of the sheet-transferring; structure taken along lines 4-4 of FIG. 8 in the directhe position 3 they take at the instant when a sheet is about to be transferred away from the supply means;

FIG. 5 shows the parts of FIG. 4 at a position immediately subsequent to that of FIG. 4 with a sheet transferred part of the way from the starting position to the end position;

FIG. 6 is an end view of the support means of the invention, partly in section, taken along line 6-6 of FIG. 8 in the direction of the arrows;

FIG. 7 is a sectional illustration of the pressure control means of the invention, taken along lines 7-7 of FIG. 8 in the direction of the arrows;

FIG. 8 is a transverse section of the structure of the invention taken along line 8-8 of FIG. 7 in the direction of the arrows; and

FIG. 9 is another transverse section of the structure of the invention taken along line 9-9 of FIG. 4 in the direction of the arrows.

Referring to FIGS. 1 and 2, it will be seen that the articles which are treated with the structure of the invention are in the form of flexible sheets Ill which can serve any desired purpose and have any desired configuration. In the illustrated example, the sheets 19 are in the form of polygonal blanks made of paper and capable of being used in the manufacture of envelopes, for example. The sheets 10 are supplied by a supply means 12 which includes lower inclined rails 14 supported by any suitable framework 16 and inclined so that the sheets will slide downwardly toward the left, as viewed in FIG. 2, to a location where the lowermost sheet is situated at a predetermined starting position.

The rails 14 fixedly carry a pair of leaf springs 18 which have free ends 2t? which slightly overlap the bottom edges of the end sheet, as indicated most clearly in FIG. 5. It is, therefore, necessary for this end sheet to be pulled over the tips of the leaf springs 18 which serve to maintain the stack of sheets 10 in the position illustrated in FIG. 2.

The framework 16 further includes an angle bar 22 (FIG. 2). This angle bar 22 is formed with openings through which a plurality of pins 24 respectively pass. These pins are fixed at their bottom ends to plates 26, and springs 28 are coiled about the pins 24 so as to urge the plates 26 against the top edges of the sheets 10 so as to maintain them properly aligned. The end sheet, which is at the starting position situated at the bottom of the stack, also engages a member 30 fixedly carried by the frame member 22.

The sheets 10 are to be transferred one after the other from the starting position which is formed by the lower end of the stack of sheets to a given end position which is situated at the right end of the conveyor means 32, also indicated most clearly in FIG. 2. This conveyor means 32 can be in the form of one or more endless belts which are continuously driven so that the upper runs move to the left, as indicated by the arrow 34 in FIG. 2. The conveyor means may be made up of a plurality of separate belts spaced from each other along the conveyor rollers, such as the conveyor roller 36 indicated in FIG. 2. Thus, from the end position situated just above and slightly to the left of the conveyor roller 36 of FIG. 2, the sheets will be transported by the conveyor means 32 in the direction of the arrow 34 to further locations where they will be further treated in any desired manner.

The structure of the inventive device includes a sup port means 38 in the form of a housing having a hollow interior. This housing has a closed end wall 40 which is circular and formed with a central opening. The housing 38 further includes an opposed end wall 42 which is formed with an opening 44. In its interior the housing includes a cylindrical hub 46 to which the end wall 42 is fixed, as by suitable screws received in tapped bores of the hub 46 shown most clearly in FIG. 3. The support means 38 is completed by a cylindrical peripheral wall 48 integral with the wall 4!} and fluid-tightly pressing against the end wall 42. This peripheral wall 43 is formed with an opening 54 shown most clearly in FIG. 3. The hub 46 is formed with an axially extending groove 52, and this grove in cross section forms part of a circle which substantially coincides with the circular opening 44, as is apparent from FIG. 6.

The support means 38 supports a sheet-engaging member 54 for movement between an outer position with respect to the support means 38, shown in FIG. 4, and an inner position with respect to the support means, shown in FIG. 5. For this purpose the closed end wall 40 of the housing 38 fixedly carries a pivot pin 56 which extends through an opening of the sheet-engaging member 54. In this way the member 54 is pivotally carried by the support means for movement between the outer and inner positions respectively shown in FIGS. 4 and 5.

The sheet-engaging member 54 has an exterior convexly curved sheet-engaging surface 58 and an inner concave surface 68 which forms a cylinder of the same radius as the exterior cylindrical surface 62 of the hub 46. As is apparent from FIG. 5, when the sheet-engaging member 54 is in its inner position its inner surface 68 engages the cylindrical surface 62 along almost the entire length of the sheet-engaging member 54. A spring means 64 is housed partly in a bore of the hub 46 and partly in a bore of the member 54 urging the latter outwardly to its outer position shown in FIG. 4. Also, it will be noted from FIG. 4 that the lower right hand corner of member 54, as viewed in FIG, 4, engages the lower end of opening 51 as viewed in FIG. 4, so as to limit turning of member 54 by the spring means 64 in this way also.

This member 54 has distant from the axis of its pivot 56 a curved end face 66 which extends along a cylinder whose axis coincides with the axis of the pivot 56. The peripheral wall 48 has, at the end of the opening 50 which is distant from the pivot 56, a curved end edge engaging the surface 66 and having the same curvature as this surface 66, so that in this way a slidable, fluid-tight engagement is provided between the surface 66 and the end face of the peripheral wall 48.

The sheet-engaging member 54 of the invention is formed with an opening 68 which passes therethrough from the convexly curved exterior surface 58 to the concave inner cylindrical surface 60. In the illustrated example this opening 68 is of rectangular or square cross section, as it is particularly apparent from FIG. 3.

A moving means 70 is operatively connected with the support means 33 for moving it along a path which will first locate the sheet-engaging member 54 at the starting position of a sheet 10, as indicated in FIG. 4, and which will then locate the sheet-engaging member at the end position situated at the conveyor means 32, as described above in connection with FIG. 2. This moving means 70 takes the form of a rotary shaft supported in any suitable bearings and extending through and fixed to the hollow housing 38. The housing 38 has, at its end distant from the end Wall 42, a hub 49 (FIG. 8) projecting beyond the end wall 40 and fixed, as by set screw 92, to the shaft 70 for rotary movement therewith.

This rotary shaft 70, in addition to being supported for rotation in any suitable bearings of the stationary framework of the machine, fixedly carries a sprocket Wheel 72 indicated in FIG. 1. This sprocket wheel is driven from a chain in any suitable way. In this way, a drive means is provided for continuously driving the moving means 70 during operation of the apparatus. Of course, drive means 72 can take any other desired form.

Thus, in the illustrated example, the moving means 70 moves the support means 38 along a circular path. During this movement along the circular path, the sheet-engaging member 54 will be displaced from the starting position where it engages a sheet 10 to the end position where the sheet 10 is delivered to the conveyor means 32.

The structure of the invention further includes a pressure-control means 74 in the form of a cylindrical block situated beside and slidably engaging the end Wall 42 of the support means 38. This cylindrical block 74 is formed with an opening 76 through which the shaft 70 freely passes. During operation, the block 74 is maintained stationary so that it forms in effect a stator with respect to which the rotary support means 38 is a rotor.

The block 74 of the pressure-control means is formed at the side face 78, which fluid-tightly and slidably engages the exterior surface of the Wall 42, with an arcuate groove 80 extending along a circle of the same radius as that along which the opening 44 turns. This groove 80 can extend through any desired angle, such as that which is shown most clearly in FIG. 7. The groove 80 communicates through a passage 82 formed in the block '74 (FIG. 9) with a conduit 84 which communicates with any suitable source of suction, such as a vacuum pump. Part of the connection of the conduit 84 is through a flexible hose so that it is possible for the block 74 to have its angular position with respect to the axis of the shaft 70 adjusted.

Beyond the groove 80 the block 74 is formed with an axial bore 86 passing completely through the block, as is apparent from FIG. 8. This bore 86 forms a vent opening. It is to be noted that the bore as is situated at the same radial distance from the axis of the shaft 70 as the arcuate groove 80 and the end wall opening 44 of the support means 38.

A collar 88 is fixed by a set screw 90 to the shaft 70, as indicated in FIG. 8, While set screw 92 fixes the exterior hub 39 of the support means 38to the shaft 70, so that in this Way the pressure-control means 74 is maintained in the position shown in FIG. 8 between the collar 88 and the support means 38 in fluid-tight, slidable engagement with the exterior surface ofthe end Wall 42 of the support means 38.

An adjusting means is provided for adjusting the angular position ofthe control means 74. This adjusting means includes an adjusting pin 94 fixed to and projecting from the block 74 in the manner shown most clearly in FIG. 9. This adjusting pin 94 is received in a notch 96 of an adjusting plate 98 which is adjustably mounted on a stationary transverse bar 100 of the supporting frame. The adjusting plate 98 may be formed with an elongated slot extending from right to left, as viewed in FIG. 1. The shank of a screw 102 can extend through this slot into a tapped bore of the bar 100, so that by loosening the screw 102 the plate 98 can be shifted so as to change the angular position of the control means 74. In this way the angular position of the groove 80 as Well as the vent opening 86 can be adjusted. Once the desired adjustment is reached the screw 102 can be tightened so that the angular position of the pressure-control 74 will remain fixed in its adjusted position.

As is apparent from FIG. 1, a pair of assemblies, as described above, are mounted on the single rotary shaft 70. Both of these assemblies operate in precisely the same Way, so that only one of the assemblies has been described.

The above-described structure operates in the following manner:

During operation of the apparatus the drive means 72 will continuously rotate the moving means which is formed by the rotary shaft 70, so that this shaft will rotate the support means 38 and will turn with respect to the control means 74. The rotary support means 38 is turned in a clockwise direction, as shown by the arrows 104 in FIGS. 4 and 5. Thus, the support means 38 is moved along a circular path and will carry the sheetengaging member 54 from the starting position shown in FIG. 4 to the end position where a sheet will be delivered to the conveyor means 32, as pointed out above.

As the support means 38 approaches the position shown in FIG. 4, the end wall opening 44 will overlap the groove 80, so that the hollow interior of the support means 38 will be in communication with a vacuum source having a pressure which is substantially less than atmospheric pressure. This communication of course takes place through the groove 80, the passage 82 and the conduit 84, which may communicate with a suitable suction pump, as pointed out above. Thus, while there will be a tendency for the hollow interior of the support means 38 to remain at substantially less than atmospheric pressure, this tendency is opposed by the flow of air from the outer atmosphere through the opening 68 of the sheet-engaging member 54 into the interior of the support means 33, in the manner shown by the ar row 106 in FIG. 4. As long as the opening 68 can communicate freely with the outer atmosphere the spring 64 is capable of maintaining the sheetaengaging member 54 in its outer position shown in FIG. 4.

As the support means 38 is moved through the position shown in FIG. 4, the exterior convex surface 58 of the sheet-engaging member 54 engages the end sheet 10. which is at the starting position, and this sheet 10 will itself close the outer end of the opening 68. so that the interior of the housing 38 no longer communicates with the outer atmosphere through the opening 68. As as result, there is a sudden increase in the differential pressure, with the result that the spring 64 no longer can maintain the sheet-engaging member 54. at the position shown in FIG. 4. Therefore, the force of the exterior atmosphere will be capable of turning the member 54 from the outer position of FIG. 4 to the inner position shown in FIG. 5, where the interior surface 60 engages the exterior surface 62. to the hub 46.

At this time the opening 68 will still. communicate through the groove 52 andthe end wall opening 44 with the arcuate groove 80, so thatthe sheet 10 will be maintained by the force of suction against the member 54 and will move with the latter, as indicated in FIG. 5. This force is great enough to displace the lower edge of the sheet 10 beyond the tips of the spring clips 20, with the result that the sheet 10 is now transferred together with the rotary support means 38 to the conveyor means 32.

When the sheet 10 has reached the conveyor means, the end wall opening 44 moves beyond the groove 80 and into communication with the vent opening 86, with the result that the hollow interior of the support means 38 now communicates With the outer atmosphere which rushed in to increase the pressure in the interior of the housing 38 so that the sheet will no longer be held by suction against the exterior surface of the sheet-engaging member 54. Thus, during the continued movement of the support means 38 along the closed circular path, formed by rotating the support means 33 with the moving means 70, the sheet will no longer be held by the support means and will instead move with the conveyor means in the direction of the arrow 34 to the left beyond the structure of the invention, as viewed in FIG. 2. During the continued turning of the shaft 70, however, th end wall opening 44 of the support means will again reach the groove 80 so as to again place the interior of the support means 38 in communication with the source of vacuum, so that the above operations will be repeated with the next sheet which has in the meantime reached the starting position engaging the tips of the spring clips 20. In this way during the continued rotation of the shaft the above operations are cyclically repeated, and the sheets are successively delivered from the stack to the conveyor.

It is to be noted that with the structure of the invention it is a sheet which closes the opening 68 so as to provide the pressure differential which results in displacement of the sheet-engaging member 54 from its outer to its inner position, pulling the sheet away from the stack and holding it in engagement with the support means so that it will be delivered to the conveyor means. In this way it is possible to completely eliminate complex cams, levers, suction heads, and the like, and with this sim le structure the controls derived from the sheets themselves will guarantee a highly reliable operation. In addition, the structure of the invention, while being simple and compact, can operate at great speed so as to have an output far beyond what has heretofore been possible. At the same time, the above structure operates very smoothly, with far less vibrations and noise than conventional structures.

Although the invention has been described with reference to a specific embodiment thereof, it is not intended that it should be limited to such specific embodiment, but it should be defined by the scope of the appended claims.

What is claimed is:

1, In an envelope making machine having means for supporting a supply of blanks and means to convey the blanks from a position adjacent the support means to a work station, improved means for moving the blanks from the support means to the conveyor means comprising; (a) a rotatable, hollow housing having a peripheral wall portion a segment part of which is movable towards and away from the rotational axis of said housing, said movable wall segment part having an aperture therethrough in communication with the interior of said housing and in contact with the leading blank during a portion of the rotation of said housing; (b) means permitting application of a suction force to the interior of said housing and through the aperture in said movable wall segment during the time said movable wall segment is in contact with the leading blank; and control means arranged to time the application and removal of the suction force with respect to the interior of said housing whereby the leading blank is carried by said movable Wall segment from the support means to a position adjacent the conveyor means upon rotation of said housing and whereby the blank is then deposited on the conveyor means for delivery to the work station when said movable wall segment is adjacent the conveyor means.

2. The apparatus in accordance with claim 13 wherein said housing comprises: (a) first and second end walls axially spaced from each other and having means for rotatably supporting said housing, said means permitting application of the suction force to the interior of said housing being an aperture in one of said end walls; and (b) a peripheral wall transversely intermediate said end Walls and defining therewithl said housing, said movable segment of said peripheral wall being pivotally mounted on one of said end walls.

3. The apparatus in accordance with claim 2 including spring means normally biasing said movable Wall segment in a direction away from the axis of rotation of said housing.

4. The apparatus in accordance with claim 2 wherein said control means is non-rotatable with respect to said housing and is positioned in fluid sealing abutment with said apertured end wall of said housing, said control means including an elongated slot arranged to register with and provide communication between the aperture in said housing end Wall and the source of suction during the time said movable Wall segment is in contact with the blank.

5. The apparatus in accordance with claim 2 wherein said control means includes means to vent the interior of said housing to the atmosphere when said movable wall segment is in a position to deposit the blank on the conveyor means.

6. The apparatus in accordance with claim 4 including means to adjust the angular relationship of said control means and said housing.

RICHARD E. AEGERTER, Prinmry Examiner.