WEB FOLDING APPARATUS AND METHOD

• US 3,841,620 A
• Filed: 02/12/1971
• Issued: 10/15/1974
• Est. Priority Date: 02/12/1971
• Status: Expired due to Term

• Current Assignee: Charles A. Lee, Horace N. Kemp, Warren R. Furbeck
• Original Assignee: Charles A. Lee, Horace N. Kemp, Warren R. Furbeck
• Inventors: Lee, Charles A., Furbeck, Warren R., Kemp, Horace N.
• Primary Examiner(s): Michell, Robert W.
• Assistant Examiner(s): Heinz, A. J.
• Application Number:
  US05/114,994
• Time in Patent Office: 1,341 Days
• Field of Search: 270/5,6,40,41
• US Class Current: 270/40
• CPC Class Codes: A47K 2010/428 Details of the folds or interfolds of the sheets
• CPC Class Codes: B65H 19/10 in unwinding mechanisms or in connection with unwinding operations
• CPC Class Codes: B65H 2301/4148 slitting
• CPC Class Codes: B65H 2301/41734 involving rail
• CPC Class Codes: B65H 45/06 Folding webs B65H20/28 takes precedence
• CPC Class Codes: B65H 45/221 incorporating folding triangles
• CPC Class Codes: B65H 45/28 Folding in combination with cutting cutting machines B26D
• CPC Class Codes: B65H 75/2437 comprising a fluid-pressure-actuated elastic member, e.g. a diaphragm or a pneumatic tube

Abstract

A machine for interfolding tissue webs which includes a series of folding devices having successive left and right pairs of curved folding shoulders, with the shoulders in each pair being spaced apart to define a generally slot-shaped opening therebetween. An adjustable conveyor draws the longitudinal edge portions of each web along the respective folding shoulders of the corresponding folding device, and the device holds the received edge portions in spaced-apart relationship with each other until after the web reaches the second succeeding folding device. The second succeeding device then closes the edge portions to fold the web into a continuously moving stack of webs. As each web is received by the corresponding folding device, a shallow trough is formed in the web, and the infeed portion of the device directs this trough at approximately a right angle with respect to the path of the continuously moving stack. The trough is then turned inside out, and the web direction is changed so that it is substantially parallel to the path of the stack. The trough is gradually closed as it moves along the curved folding shoulders of the device and on past the next and then the next device. Before the trough is completely closed, an edge portion of the succeeding web is inserted therein. The webs are led to the folding devices from a plurality of supply rolls disposed along a single side of the machine. One supply roll is provided for each group of four folding devices, and the material from each roll is cut to the appropriate width to form the webs as it is advanced toward the folding devices. The various supply rolls include inflatable core assemblies which may be quickly and easily inserted in and withdrawn from the paperboard cores of the rolls. When the material from a given roll is exhausted, a back-up roll is moved into position, and the spent core is deposited on a conveyor which transports it to one end of the machine.

Claims

1. In apparatus for longitudinally interfolding a plurality of webs and for advancing the interfolded webs in a continuously moving stack along a feed path, in combination:

a plurality of folding devices mounted in spaced relationship with each other along the feed path, each of said folding devices having an infeed surface and an outfeed surface extending from and continuous with said infeed surface in the direction of movement of the stack along the feed path, said outfeed surface including a pair of gradually curved diverging folding shoulders, at least one of said folding shoulders extending at an angle from a portion of the infeed surface adjacent the feed path obliquely across at least a portion of the feed path, and outfeed surface portions extending laterally from said folding shoulders defining a concave surface, as viewed from the preceding folding device, between the folding shoulders for concavely folding the portion of a web drawn therebetween, said folding devices being disposed along the feed path so that the concave outfeed surface portion of each folding device can receive the portion of the folded web from the preceding folding device to be interfolded with the web supplied to said folding device;

means associated with each of said folding devices for guiding the portion of the folded web from the preceding folding device to be interfolded with the web supplied to said folding device into the concave outfeed surface portion of said folding device so that the folding shoulder which extends across the feed path is interposed between said portion of the folded web to be interfolded and the remainder of said folded web opposiTe said portion;

means for supplying a web to each of the folding devices; and

means for drawing the web supplied to each of the folding devices over the infeed and outfeed surfaces of said folding device and into the stack so that said web is folded concavely around the portion of the folded web from the preceding folding device guided into the concave outfeed surface portion of said folding device as said web passes the outfeed surface of said folding device and so that a portion of said web on the side of the fold adjacent the interposed folding shoulder is gradually interposed between the folded surfaces of the web from the preceding folding device by said interposed folding shoulder to interfold said web and the web from the preceding folding device, and a portion of the web on the other side of the fold is positioned by the other folding shoulder for guiding into the concave outfeed surface portion of the succeeding folding device.

2. The apparatus defined in claim 1 wherein the infeed surface of each folding device is substantially perpendicular to the feed path.

3. The apparatus defined in claim 2 wherein the infeed surface of each folding device is substantially triangular.

4. The apparatus defined in claim 44 wherein the folding shoulders of each folding device extend from the region of a corner of the triangular infeed surface of said folding device.

5. The apparatus defined in claim 1 wherein said means for supplying comprises:

a plurlaity of supply rolls of sheet meaterial;

means for longitudinally slitting said sheet material from said supply rolls to produce a plurality of webs; and

means for respectively directing said webs to said folding devices.

6. The apparatus defined in claim 1 wherein said means for drawing comprises conveyor means for supporting the stack of interfolded webs and for advancing said stack along said feed path.

7. The apparatus defined in claim 6 further comprising means for adjusting the position of said conveyor relative to said folding devices in accordance with the number and thickness of webs in said stack.

8. The apparatus defined in claim 1 wherein the outfeed surface of each of said folding devices further includes an extension of the folding shoulder which is not interposed between portions of the folded web from the preceding folding device for longitudinally creasing the portion of the web supplied to said folding device adjacent said folding shoulder extension in the opposite direction from said concave fold and wherein said apparatus further includes means associated with each of said folding devices and disposed in spaced relationship therewith for defining an opening therebetween for receiving the portion of the web extension from the crease formed by said folding shoulder extension in the direction away frm said concave fold and for further positioning the received portion of the web for guiding into the concave outfeed surface portion of the succeeding folding device.

9. In apparatus for longitudinally interfolding a plurality of webs and for advancing the interfolded webs in a continuously moving stack along a feed path, in combination:

a plurality of folding devices mounted in spaced relationship with each other on alternate sides of the feed path, each of said folding devices having an infeed surface and an outfeed surface extending from and continuous with said infeed surface in the direction of movement of the stack along the feed path, said outfeed surface including a pair of gradually curved diverging folding shoulders extending from a portion of the infeed surface adjacent the feed path obliquely across at least a portion of the feed path, and outfeed surface portions extending laterally from said folding shoulders, said outfeed surface portions and folding shoulders respectively defining convex surfaces as viewed from the preceding folding device, outside the folding shoulders and a concave surface between the folding shoulders, said outfeed surface being substantiaLly convex adjacent the infeed surface and becoming substantially concave as the folding shoulders diverge toward the outfeed end of the folding device, for forming a convex longitudinal trough in a web drawn over the outfeed surface of the folding device and for gradually inverting said trough as the web is drawn over the folding shoulders and into the concave outfeed surface portion between the folding shoulders, the outfeed surface portions defining the bottom of the concave outfeed surface being sufficiently close together to concavely crease the portion of the web drawn therebetween;

means associated with each of said folding devices for preventing the inverted trough in the web from the preceding folding device from closing and for guiding one edge of the web from the preceding folding device into the concave outfeed portion of said folding device so that one of the folding shoulders of said folding device projects at least partially into said inverted trough for interfolding said edge with the web supplied to said folding device;

means for supplying a web to each of the folding devices; and

conveyor means for drawing the web supplied to each of the folding devices over the infeed and outfeed surfaces of said folding device and into the stack so that said web is creased concavely around the edge of the web from the preceding folding device guided into the concave outfeed surface portion of said folding device as said web passes the outfeed surface of said folding device, and so that at least a portion of the web on the side of said crease adjacent the folding shoulder projecting into the inverted trough in the web from the preceding folding device is gradually introduced into said inverted trough by said projecting folding shoulder and is thereby interfolded with the web from said preceding folding device.

10. The apparatus defined in claim 9 wherein the infeed surface of each folding device is substantially perpendicular to the feed path.

11. The apparatus defined in claim 10 wherein the infeed surface of each folding device is substantially triangular.

12. The apparatus defined in claim 11 wherein the folding shoulders of each folding device extend from the region of a corner of the triangular infeed surface of said folding device.

13. The apparatus defined in claim 12 wherein the outfeed surface portions of each of said folding devices defining said convex surface extend from the two sides of the triangular infeed surface adjacent the region of said corner of the triangular infeed surface of said folding device.

14. The apparatus defined in claim 13 wherein the periphery of the triangular infeed surface of each of said folding devices is indented in the region of said corner of said triangular surface to define a keyhole-shaped aperature in said infeed surface between said folding shoulders for initiating formation of the inverted trough in the web drawn over said folding device.

15. The apparatus defined in claim 9 wherein said means for supplying comprises:

a plurality of supply rolls of sheet material;

means for longitudinally slitting said sheet material from said supply rolls to produce a plurality of webs; and

means for respectively directing said webs to said folding devices.

16. The method of longitudinally interfolding a plurality of webs to produce a stack of interfolded webs moving continuously along a feed path comprising the steps of:

respectively guiding said webs to a plurality of locations on alternate sides of said feed path;

forming a convex longitudinal trough in each of said webs as it is guided to said feed path, said trough being convex as viewed from the preceding web approaching the feed path and having a longitudinal axis which meets the feed path at an acute angle;

gradually inverting a medial portion of the convex trough in each of said webs as said web merges with the stack of webs to form a concave longitudinal trough in said web;

guiding a first edge portion of the cOncave trough in each of said webs into the concave trough of the preceding web to interfold said web with the preceding web;

guiding the remaining edge portion of the concave trough in each of said webs into the concave trough of the succeeding web to permit the succeeding web to be interfolded with said web; and

closing the concave trough in each of said webs following completion of the two immediately preceding steps for said web.

17. The method of longitudinally interfolding a plurality of webs to produce a stack of interfolded webs moving continuously along a feed path comprising the steps of:

respectively guiding said webs to a plurality of locations along one side of said feed path;

forming a convex longitudinal trough in each of said webs as it is guided to said feed path, said trough being convexly bowed out toward one lateral side of the feed path as viewed from the preceding web approaching the feed path and having a longitudinal axis which meets the feed path at an acute angle;

gradually inverting a portion of the convex trough in each of said webs as said web merges with the stack of webs to form a concavely bowed trough facing said one lateral side of the feed path in a portion of said web while maintaining a parallel convex trough in the lateral portion of said web adjacent the concave trough;

guiding an edge portion of the concave trough in each of said webs into the convex trough of the preceding web to interfold said web with the preceding web;

guiding an edge portion of the convex trough in each of said webs into the concave trough of the succeeding web to permit the succeeding web to be interfolded with said web; and

closing the concave and convex troughs in each of said webs following completion of the two immediately preceding steps for said web.