US3789714A

US3789714A - Web feeding and cutting arrangements

Info

Publication number: US3789714A
Application number: US00173707A
Authority: US
Inventors: H Demny
Original assignee: Maschinenfabrik Alfred Schmermund GmbH and Co
Current assignee: Maschinenfabrik Alfred Schmermund GmbH and Co
Priority date: 1968-07-19
Filing date: 1971-08-12
Publication date: 1974-02-05
Anticipated expiration: 1991-02-05
Also published as: BE736087A; DE1935918A1; CH501547A; FR2013253A1; GB1215047A

Abstract

This invention relates to an arrangement for feeding a web of material through a cutting device. Independently operable withdrawing and guiding means for drawing two webs of material from respective bobbins are provided. Both webs are brought into the vicinity of the cutting device. One web remains at rest, while the other, in an intermittent motion, travels further into the cutting device and is transversely cut by this device during stop periods of this travel. When the trailing end of the first web is detected, indicating that the supply of web from the first bobbin is exhausted, the other web is traversed through the cutting device whilst the first bobbin is replenished.

Description

United States Patent 1191 Demny 1451 Feb. 5, 1974 WEB FEEDING AND CUTTING ARRANGEMENTS [75] Inventor: Helmut Demny,

Gevelsberg/Westfalen, Germany Related U.S. Application Data [63] Continuation-impart of Ser. No. 838,963, Aug. 12,

1971, abandoned.

[30] Foreign Application Priority Data July 19, 1968 Great Britain 34,599/68 [56] References Cited UNlTED STATES PATENTS Small 83/272 X 3,160,047 1'2/1964 Malloy et 51 83/65OX Primary Examiner-Frank T. Yost. Attorney, Agent, or FirmSughrue, Rothwell, Mion, Zinn & Macpeak [5 7] ABSTRACT This invention relates to an arrangement for feeding a web of material through a cutting device. Independently operable withdrawing and guiding means for drawing two webs of material from respective bobbins are provided. Both webs are brought into the vicinity of the cutting device. One web remains at rest, while the other, in an intermittent motion, travels further into the cutting device and is transversely cut by this device during stop periods of this travel. When the trailing end of the first web is detected, indicating that the supply of web from thefirst bobbin is exhausted, the other web is traversed through the cutting device whilst the first bobbin is replenished.

4 C| aims,3 Drawing Figures PATENTEB B' 51974 INVENTOR HELMUT DEMNY PATENIEDFEB 5:974

saw 2 or z INVENTOR HELMUT DEMNY BY %Z/@W/MI v ATTORNEYS web and to its travel,

BACKGROUND OF THE INVENTION The invention relates to an arrangement for web feeding and cutting, the web being of flexible material. Such arrangements are, for example, used in connection with or form part of wrapping machines for enveloping articles or collections of articles in flexible wrappers.

-. SUMMARY OF THE INVENTION leading end disposed just short of the cutter. When the trailing end of the first web is detected approaching the cutter, indicating that one of the bobbins is exhausted, the feeding .means for the first web is rendered inoperative whilst the feeding means for the other web is rendered operative.

Advantageously the motion of the web is intermittent and the cutting occurs in a motion transverse to the this travel.

BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION or THE PREFERRED EMBODIMENT Y The embodiment illustrated comprises means in the shape of two shafts 1 and 101 for rotatably carrying two bobbins 2 and .102, each for storing a web Band 103 respectively. The shaftsl and 101 are mounted on a support 4 the shape of which maybe suited to requirements of each case. Rods 5 and 105, rotatably mounted respectively on shafts 6 and 106 held by the carrier 4, are provided with rollers 7 and 107 which guide the webs 3 and 103. The rollers 7 and 107, under the action of suitable spring means (not shown) or under the action of gravity, tension the webs 3 and 103. Further guide rollers 8 and 108 mounted on the support 4 guide the webs 3 and 103 to means for drawing each web from its bobbin 2 or 102 respectively, the drawing means being in the shape of two pairs of

co-operating rollers

16, 17 and 116, 117 rigidly connected to pairs of normally meshing gear ,

wheels

11, 12 and 111, 112. Guiding means 13 and 113 guide the webs 3 and 103 so that they approach each other at an acute angle before they reach a reciprocatable cutter blade 14 and are parallel and close to 'each other immediately in front'ofthe cutter blade '14. The cutter blade 14 cooperates with a stationary cutter blade 15 (see also FIG. 3). Through a lever arrangement 18 the reciprocatable cutter 14 is operable by an oscillating shaft 19 which is oscillatable by a cam arrangement (not shown) and spring means 22.

The pairs of

gear wheels

11, 12 and 111, 112 are driven by a rotatable main shaft 23 through a gear wheel 24 geared thereto and through

further gear wheels

25, 26, 27, 28 and two electromagnetic couplings 31, one for each of said pairs of

gear wheels

11, 12 and 111, 112. Only one of the electromagnetic couplings 31 is visible in FIG. 2. The electromagnetic couplings are operable 'by electric coils 32 only one of which is visible in FIG. 2. The gear wheels 11 and 111 are in operation rotated only when the respective electromagnetic coupling is actuated by energizing its electric coil 32.

Manually

operable handles

33, 133 enable the rollers 17, 117 to be removed against the action of springs 34, 134 from the rollers 16, 116 to facilitate the insertion of the webs 3, 103. between the respective pair of

rollers

16, 17 and 116, 117.

during short stopping intervals of Further handles 35, 135 permit the respective pair of

rollers

16, 17 or 116, 117 to be manually rotated in steps.

The embodimentdescribed operates as follows:

The webs 3 and 103 are manually drawn from the bobbins 1, 102, passed about the rollers 7, 107, and the further rollers 8, 108. The handles 33,133 are operated so that the rollers of each pair of rollers l6, l7 and 116, 117 are distanced from each other, and the leading ends of the webs are inserted between the rollers of each pair. Subsequently, the

handles

33, 133 are returned to their normal positions so that each web 3, 103 is gripped between the respective pair of

rollers

16, 17 and 116, 117. The handles 35, 135 are; now oscillated whereby the

rollers

16, 17 and 116, 117 are rotated in steps until the'leading ends of the webs 3, 103 travelling through the guiding means 13, 113 lie immediately in front of the cutter 14 One of the electromagnetic couplings 31 is rendered operative by energizing its electric coil 32 so that the respective pair of

rollers

16, 17 or 116, 117 starts rotating, thereby drawing one of the webs 3 or 103 past the cutters 14, 15, which are operated, in a manner known per se to cut predetermined lengths of wrapping material from the respective web.

When the supply of this web is exhausted the electric coil 32 of one of the electromagnetic couplings 31 is de-energized andthe other electric coil 32 of the other done manually by operating selector switch means or,

preferably, automatically by means, for example, of photoelectric devices. A pair of such photoelectric sensing devices are indicated schematically in FIG. 1 by the

light sources

300 and 400 and corresponding

photosensitive receivers

301 and 401. These receivers incorporate suitable amplifying and inverter devices to provide control signals which de-energize one of the electric coils 32.0f one of the electromagnetic couplings 31 and energize the electric coil 32 of the other electromagnetic coupling. The electrical connections between the

photosensitive receivers

301, 401 and the corresponding electric coils 32 are not shown in the drawing since these connections and associated control devices may be of a kind well known per se When one of the

photoelectric sensing devices

300, 301 and 400,

401 senses the trailing end of the corresponding one of the webs 3 or 103 approaching the cutter 14, the respective' device provides a control signal for deenergizing the electric coil 32 of the corresponding electromagnetic coupling and energizing the electric coil 32 of the other electromagnetic coupling. This renders the first electromagnetic coupling inoperative and the other electromagnetic coupling operative, This causes the other pair of rollers to rotate so as to draw the other web from its bobbin and feed it to the cutters 14, 15. While this continues the empty bobbin 2 or 102 (as the case may be) is removed and replaced by a fresh, loaded bobbin. Its web is manually passed about the

rollers

7 and 8 or 107 and 108. The

appropriate handle

33 or 133 is operated so that the nonrotating pair of rollers 16, 17 or 116, -117 are distanced from each other. When the

handle

33 or 133 is returned to its normal position, the web is gripped between the non-rotating pair of rollers'16, 17 or 116, 117. The said non-rotating pair of rollers is now rotated in steps by manually oscillating 'the respective handle 35 or 135. Thereby the leading end of the fresh web is moved'forward. Oscillating of the handle 35 or 135 is interrupted when the leading end of the fresh web is at a short distance of about 1 millimetre from the reciprocating cutter 14. The insertion of the fresh web can be effected while the other web continues to travel beyond the cutters 14 and 15, when the supply of the other web ceases, the electromagnetic couplings are again actuated so that the pair of rollers rotating up to now are stopped and the other pair of rollers are rotating.

It will be noted that with the embodiment described it is no longer necessary to stop the machine, for example a wrapping machine, to which the webs are fed when the supply of web is exhausted and a bobbin has to be exchanged, nor is it necessary to glue the trailing end of one web to the leading end of the next web which may necessitate removal of at least one of the wrapped articles whose wrapping shows the connection of two webs as faulty. With the present arrangement the length of the piece of wrapping material which is cut first from a fresh web is slightly shorter by about 1 millimetre than the normal length of the pieces. This small difference in length, however, is usually admissible so that for this reason no wrapped article need be rejected.

Provision is made to interrupt the feed of a web while cutting takes place. This may be effected automatically by de-energizing the respective coupling while cutting is effected. Alternatively or additionally, suitable control means 23 may be provided, whereby the main shaft 23 may be rotated intermittently so that, again, the feed of web is interrupted while cutting takes place.

What I claim is:

1. A web feeding and cutting machine comprising;

a support;

two rotatable bobbins mounted on said support, each of said bobbins being adapted to store a web;

a pair of pinch rollers corresponding to each of said bobbins and adapted to selectively engage a web stored on the bobbins corresponding thereto, thereby drawing said web therebetween when said pinch rollers are drivenin rotation;

means for driving each of said pairs of pinch rollers;

means corresponding to each of said pairs of pinch rollers for guiding said webs from said pinch rollers to a common cutting zone; I

means for cutting'said webs in said common cutting zone; I

means for detecting the end of a web being drawn into said common cutting zone;

means responsive to said detecting means for automatically stopping the driving of the pair of said pinch rollers drawing the web the end of which has been detected and starting the driving of the other pair of said pinch rollers; and

manually operable means for rotating' said pairs of pinch rollers, whereby the leading edge of said webs may be positioned immediately upstream of said cutting means prior to actuation of said means 1 for driving said pinch rollers.

2. A web feeding and cutting machine as claimed in claim 1 wherein said means for guiding said webs are adapted to cause said webs to define an acute angle therebetween upstream of said cutting means and to be parallel and close to each other immediately upstream of said cutting means.

3. A web feeding and cutting machine as claimed in claim 1 wherein said means for driving each of said pairs of pinch rollers comprises an electromagnetic coupling and wherein said detecting means comprises one or more photoelectric sensing devices.

4. A web feeding and cutting device as claimed in I claim 1 wherein provision is made to interrupt the feed of web while cutting takes place.

Claims

1. A web feeding and cutting machine comprising; a support; two rotatable bobbins mounted on said support, each of said bobbins being adapted to store a web; a pair of pinch rollers corresponding to each of said bobbins and adapted to selectively engage a web stored on the bobbins corresponding thereto, thereby drawing said web therebetween when said pinch rollers are driven in rotation; means for driving each of said pairs of pinch rollers; means corresponding to each of said pairs of pinch rollers for guiding said webs from said pinch rollers to a common cutting zone; means for cutting said webs in said common cutting zone; means for detecting the end of a web being drawn into said common cutting zone; means responsive to said detecting means for automatically stopping the driving of the pair of said pinch rollers drawing the web the end of which has been detected and starting the driving of the other pair of said pinch rollers; and manually operable means for rotating said pairs of pinch rollers, whereby the leading edge of said webs may be positioned immediately upstream of said cutting means prior to actuation of said means for driving said pinch rollers.

4. A web feeding and cutting device as claimed in claim 1 wherein provision is made to interrupt the feed of web while cutting takes place.