US3565731A

US3565731A - Splicing devices

Info

Publication number: US3565731A
Application number: US589748A
Authority: US
Inventors: Alfred Schmermund
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-11-04
Filing date: 1966-10-26
Publication date: 1971-02-23
Anticipated expiration: 1988-02-23
Also published as: CH462689A; GB1150322A; DE1511791A1; DE1786503B1; BE689186A

Abstract

A SPLICING DEVICE COMPRISING PRESSING MEANS, MEANS FOR FEEDING A TRAVELLING WEB AND THE LEADING PORTION OF A STAND-BY WEB BETWEEN THE PRESSING MEANS, MEANS FOR MOVING THE PRESSING MEANS TOWARDS EACH OTHER TO PRESS A PORTION OF THE TRAVELLING WEB AND THE LEADING PORTION OF THE STAND-BY WEB TOGETHER, AND MEANS FOR DISPLACING THE PRESSING MEANS TO TRAVEL JOINTLY ALONG THE PATH OF THE WEBS WHILST PRESSING THE WEBS TOGETHER. ADVANTAGEOUSLY, MEANS ARE PROVIVED FOR PRE-HEATING THE PRESSING MEANS SO THAT WEBS OF THERMOPLASTIC MATERIAL OR HAVING SPLICE PORTIONS WITH A THERMOPLASTIC COATING ARE WELDED.

Description

Feb. 23, 1971 SCHMERMUND 3,565,731

SPLICING DEVICES Filed 001:. 26. 1966 7 Sheets-Sheet 1 V #59728 415660 SCI/MEEAMA/O Feb. 23, 1971 A. SCHMERMUND 3,565,731

SPLICING DEVICES Filed Oct. 26. 1966 7 Sheets-Sheet a av 47/ M1 /112 JTI'JEA/E'YS Feb. 23, 1971 A. SCHMERMUND- SPLICING DEVICES 7 Sheets-Sheet 8' Filed 001;. 26. 1966 mmswrae #lFZEfl su/MaeMu/ya 77% M1 Wm A rm levers Feb. 23, 1971 A. SCHMERMUND SPLICING DEVICES 7 Sheets-Sheet c Filed Oct. 26. 1966 'ima M W44 Feb. 23, 1971 A. SCHMERMUND 3,565,731

SPLICING DEVICES Filed Oct. 26. 1966 7 Sheets-Sheet 5 nwnvrne flzre-o sc #Mezwwvo WMZM/WA Feb. 23 1971 A. SCHMERMUND 3,565,731

srmcme DEVICES Filed Oct. 26, 1966 7 Sheets-Sheet 6 Fig.7

WA .wm

Feb. 23, 1971 A. SCHMERMUND 3,565,731

- "sPLIcING DEVICES Filed Oct. 26,: 1966 7 Sheets-Sheet 7 //V E/v7'o 144E650 sc iwfeu zmp United States Patent O l 3,565,731 SPLICING DEVICES Alfred Schmermund, 62 Kornerstrasse, Gevelsberg, Westphalia, Germany Filed Oct. 26, 1966, Ser. No. 589,748 Claims priority, application Great Britain, Nov. 4, 1965, 46,701/65 Int. Cl. B65 69/00 U.S. Cl. 156504 6 Claims webs whilst pressing the webs together. Advantageously, 20

means are provided for pre-heating the pressing means so that webs of thermoplastic material or having splice portions with a thermoplastic coating are welded.

BACKGROUND TO THE INVENTION The invention relates to splicing devices for connecting together webs of material, for example webs of cellulose glass, foil or paper. Such splicing devices are especially 30 useful in connection with packing machines or cigarette making machine in which webs of material are alternately supplied from two reels, an end portion of a web supplied from one reel being connected to the beginning 3,565,731 Patented Feb. 23, 1971 Means may be provided for cutting off unessential parts of the web portions to be connected together.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects and advantages of the invention will become clear from the following detailed description thereof when read in conjunction with the accompanying drawings, which are given by way of example and in which:

FIG. 1 shows a side view, in section, of a first embodiment of the invention;

FIG. 2 shows a side similar to FIG. 1 but with some of the parts displaced from the positions in which they are shown in FIG. 1;

FIG. 3 shows a view taken in section along the line III-III of FIG. 1 omitting some of the parts shown in FIG. 1;

FIG. 4 shows a side view, in section, of a second embodiment of the invention;

FIG. 5 shows a view taken in section along the line VV of FIG. 4;

FIG. 6 shows in side view, a modified detail of the embodiment of FIGS. 4 and 5;

FIG. 7 shows a side view, in section, of a third embodiment of the invention; and

FIG. 8 shows a view taken in the direction of the arrow A of FIG. 7, some of the parts of FIG. 7 being omitted.

DESCRIPTION OF EMBODIMENTS The embodiment of FIGS. 1 and 2 comprise two reels 1a and 112 for

supply webs

2a and 2b, of which the web 2a is travelling, for example, to a packing machine, and the web 2b is a stand-by web. The

webs

2a and 2b are of a web supplied from the other reel so that the supply guided by guide rollers 3a and 3b respectively to guides of web is not, or not unduly, interrupted.

It is an object of the invention to provide a splicing device by means of which two web portions are connected together without interrupting the supply of web material, and while travelling.

SUMMARY OF THE INVENTION The invention consists in a splicing device comprising pressing means, means for feeding portions of a travelling web and a stand-by web between the pressing means, means for moving the pressing means towards each other to press the two web portions together, and means for displacing the pressing means while pressing the web portions together so as to follow the travelling webs. Thereby, the pressure may be exerted by the pressing means for a sufficiently long time while the webs continue to travel. The pressing means may comprise jaws.

The web portions may be made of a material, or may be coated or impregnated with a material, which is adhesive at normal room temperature, the web portions being connected by the pressure exerted by the jaws.

However, means may be provided for heating one of the jaws or both jaws preferably before the jaws exert pressure on the web portions whereby to connect the web portions under heat and pressure. In this case, the web portions may be made of a material, or may be coated or impregnated with a material, which becomes adhesive under heat.

Means may be provided for actuating the heating means when the end of a web approaches the jaws.

If the end portion of a web is to be coated or impregnated with an adhesive material, a storage container for the adhesive material may be provided, means being provided for applying the adhesive material to the web portion before the web portion reaches the jaws. Preferably, both web portions to be connected are coated or impregnated by the applying means.

4a and 4b which are rotatably mounted by pivots 5a and 5b. In their normal, operative, position, the

guides

4a and 4b are inclined relatively to each other as shown in FIG. 1. On the

guides

4a and 4b, the guide rollers 3a and 3b are rotatably mounted. The

guides

4a and 4b also carry cutters 8a and 8b for cutting the webs. The

guides

4a and 4b together with the guide rollers 3a and 3b and the cutters 8a and 8b are turnable independently of each other about the pivots 5a and 5b respectively into retracted positions so as to facilitate introducing the

respective web

2a or 2b. Web retainers 9a and 9b are pivotally secured to the

guides

4a and 4b for retaining the

webs

2a and 2b. The

guides

4a and 4b are each provided with perforations 10a and 10b connected by ducts 11a and 11b in the

guides

4a and 4b, and by pipes 12a and 12b to a source of suction (not shown) to enable the

webs

2a and 2b, when not travelling, to be held by suction against the

guides

4a and 4b.

When the end of one of the webs, for example the web 2b, is to be inserted into the device the guide 4b is moved manually into the retracted position as shown in FIG. 2 with respect to the guide 4b, the end of the web 2b is then manually passed over the guide roller 3b, threaded between the web retainer 9b and the guide 4b eand laid on the guide 4b over the perforations 1% so as to be retained against the guide 4b by suction. The guide 4b is then pivoted back into the position shown in FIG. 1.

The cutters 8a and 8b are slidable in slots 17a and 17b in the

guides

4a and 4b and are pivotally connected to arms 18a and 18b of two pairs of three-armed levers indicated generally by reference numerals 19a and 1% (only one of each pair being visible in FIG. 1). The levers 19a and 19b are pivotally mounted by pivot pins 20a and 20b on projections 21a and 21b on the

guides

4a and 4b and have

further arms

22a, 22b and 23a, 23b respectively. Tension springs 25a and 25b urge the cutters 8a and 8b towards the

webs

2a and 2b and towards a stationary counter-element 63, and tend to pivot the levers 19a and 19b about the pivot pins 20a and 20b, the cutters 8a and 8b and the levers 19a and 19b being retained in the positions shown in FIG. 1 by engagement of the

lever arms

23a and 23b with a common pawl 27. As shown in FIG. 3, the pawl 27 is pivotally mounted on the main frame of the arrangement, an electromagnet 61 being provided for pivoting the pawl 27 against the action of a spring 62. Two pairs of stops 28a and 28b (only one of each pair being visible in FIG. 1) pivotally mounted on the projections 21a and 21b by shafts 29a and 2% are manually turnable into locking positions to engage the

arms

23a and 23b and thereby to retain the levers 19a and 19b and therewith the cutters 8a and 8b against the action of the springs 25a and 25b when the pawl 27 is released on energization of the electromagnet 61. One of the stops 28a is shown in its locking position in FIG. 1. Curved

stationary abutments

30a and 30b are arranged for co-operating with arms 31a and 31b of the stops 28a and 28b to ensure that the stops 28a and 28b are pivoted into their locking positions as shown with respect to stop 28b in FIG. 2, when the

respective guides

4a and 4b are pivoted into their retracted positions. The pawl 27 is magnetically releasable so that after release of the pawl 27 that cutter 8a or 8b is operable which is not secured in position by the stops 28a or the stops 28b.

Two

heating jaws

32a and 32b are provided which are normally spaced apart from each other. The

jaws

32a and 32b are each mounted on a parallelogram guide arrangement comprising links 33a and 33b carried on

links

34a, 34b, 35a and 35b, which are pivotally connected to a frame comprising

end members

37a and 37b connected by transverse members 38, 39' and 40 (FIG. 3). The arms 34a and 3412 are linked by meshing toothed ends of arms 41a and 41]) which ensure corresponding movements of the

arms

34a, 35a and 34b, 35b. The

jaws

32a and 32b are urged together by a tension spring 42 but are normally held apart by a connecting member 44 pivoted to a lever arm 45 which is rigid with a lever arm 46 retained by a pawl 47. The

jaws

32a and 32b are provided with electric heating elements 48a and 48b (not shown which, when the

jaws

32a and 32b are in the positions shown in FIG. 1, are connected to contacts comprising

contact elements

49a and 49b bearing against

resilient contact arms

50a and 50b. Each of the reels 1a and 1b lasts for a considerable time, for example two hours. In order to ensure that the heating elements 48a and 48b are supplied with electric current only shortly, for example about 5 minutes, before a reel is exhausted, known devices are provided for controlling the supply of electric current to the

contact arms

50a and 50b from a current supply source (not shown). One of these devices, associated with the reel 1a, is shown, and comprises contact elements 59 controlled by a feeder arm 60 resiliently urged against the peripheries of the reel 1a, the contact element 59 being electrically connected in series with the

contact arm

50a and 50b. A similar control device which in part is shown in broken lines in FIG. 1 co-operates with the reel 1b.

The frame comprising the

end members

37a and 37b and the transverse members 38, 39 and 40 (see also FIG. 3) is carried on an arm 52 which is pivotable about a shaft 53 mounted in

uprights

541 and 551 forming parts of a main frame of the arrangement. The arm 52 is retained in the position shown in FIG. 1 by engagement of the link 33a with an abutment 54 fixed to the main frame.

The retaining pawl 47 forms one arm of a two-armed lever pivotally mounted on the arm 52 and releasable by energization of an electromagnet 55 linked to the pawl 47 by a two-armed lever 56 turnable about a fixed pivot pin 57. On release of the pawl 47, the

jaws

32a and 32b snap towards each other under the action of the 4 tension spring 42, the link 33a disengaging the abutment 54, whereupon the arm 52 pivots downwards about the shaft 53. An abutment lever is linked to the arm 52 through the lever arm 46 and arranged for co-operation with a stationary abutment 66 In operation, one of the

webs

2a and 2b travels between the spaced-

apart jaws

32a and 32b, the beginning of the other stand-by web lying stationarily between the jaws. As shown in FIG. 1, the web 2a is the travelling web and the web 2b is the stand-by 'web. After the standby web 2b has been placed in position on the guide 4b by an operator, the operator manually turns the stop 28a by means of its arm 31a from its locking position shown in FIG. 1 into its non-locking position. By turning the guide 4b while placing the stand-by web 2b into position, the stop 28b is automatically turned from its non-locking position shown in FIG. 1 into its locking position. When by means of the respective feeler arm 60 the approach of the end of the travelling web 2a has been sensed the contact elements 59 controlling the supply of electric current to the heating elements 48:: and 48b are closed whereby the

jaws

32a and 32b are heated. Subsequently, when the feeler arm 60 senses the end of the travelling web, the electromagnets 61 and 55 are energized and attract. Thereby, the pawl 27 releases the cutter levers 19a and 1% with the cutters 8a and 8b. By energization of the electromagnet 55, the pawl 47 is released and the

heated jaws

32a and 32b are forced together under the action of the spring 42 and press together and heat the adjacent web portions under pressure whereby they are welded together. While the

jaws

32a and 32b move with the Webs, the arm 52, which carries the

jaws

32a and 32b, turns about the shaft 53 under the action of gravity. Furthermore, when the pawl 27 is released the end of travelling web 2a is cut off by the cutter 8a in co-operation with its stationary counter-element 6.3. In the foregoing it has been assumed that the webs are made of a material which becomes tacky under heat. Alternatively, the webs may be coated or impregnated with a material that becomes tacky under heat.

When the jaws have nearly reached the end of their travel, as shown in FIG. 2, they are opened when the abutment lever 65 rigid with the lever arm 46 strikes the stationary abutment 66 causing the pawl 47 to re-engage the lever arm 46. Subsequently, the arm 52 with the

jaws

32a and 32b is manually returned into its position shown in FIG. 1 and locked by engagement of the link 33a with the abutment 54. The cut-off remainder of the web 2a is removed by hand. A fresh web from a fresh reel is now introduced between the

guides

4a and 4b and the stops 28a and 28b are adjusted, the introduction of the fresh web being facilitated by first turning the guide 4a with the cutter 8a into the retracted inoperative position as described above with respect to the guide 4b whereby access to the guide 4a is facilitated.

It should be noted that FIG. 2 illustrates the web 2a at the beginning of its travel and the guide 4b turned for inserting the stand-by web 2b. FIG. 1 illustrates the further travel of the web 2a but shows the stop 28b prior to the guide 4b being turned. Furthermore, the electric circuits for the electromagnets have not been shown since their arrangements are obvious.

In the embodiment of FIGS. 4 and 5, two

webs

102a and 102b are guided by

guide rollers

103a, 103b, 104a, 104b between a pair of heating jaws 105a and 105b, which are resiliently mounted on rotatable supports 106a and 106b carried on

shafts

107a and 107b. The jaws 105a and 105b are heated electrically through sprung contacts 110 provided on side walls 109, (FIG. 5). The jaws 105a and 10512 are provided with heater elements 111a and Illb of low ohmic resistance, electric current being supplied at low voltage to avoid or reduce arcing. In FIG. 4, the web 102a is shown travelling between the jaws 1050 while the web 10% is the stand-by web. When a feeler arm (not shown) detects in a manner analogous to that described with reference to the first embodiment that the web 102a is almost exhausted, the heating elements receive current and heat the jaws 105a and 105b. When the end of the web 102a approaches the jaws 105a and 105b, a single revolution clutch indicated generally by reference numeral 112 (FIG. is operated to rotate the

shafts

107a and 107b and thereby to rotate the jaws 105a and 10511 through one revolution. The webs extend between

rollers

114a and 114b to the jaws 105a and 10512 and as the end of the web 102a approaches the roller 11412 is rotated to feed the web 102b towards the jaws 105a and 10512, which approach each other and press the

webs

102a and 102b together so that the

webs

102a and 102b are welded together, the jaws 105a and 10512 travelling with the

webs

102a and 102b and being pressed inwardly of the supports 106a and 1061;. Subsequently, the jaws 105a and 105b move away from each other and after completion of one rotation come to rest.

Cutters 115a and 11511 are provided for cutting the webs 102a and 10217, and are controlled by electromagnets 116a and 116b. Two-armed levers 118a and 11% operated by the electromagnets 116a and 11611 are formed with pawls 119a and 119b engageable with levers 120a and 12012 which are rigidly connected with further levers 121a and 121b, which in turn are pivotally connected to the cutters 115a and 115b. Tension springs 122a and 12211 tend to urge the cutters 115a and 115b towards a counter-element in the form of a fixed bar 114 extending between the paths of the

webs

102a and 102b so that when the electromagnet 116a, for example, is energized the pawl 119a releases the lever 120a and the tension spring 122a moves the cutter 115a against the web 102a, which is cut between the cutter 115a and the bar 114.

For facilitating the introduction of the

webs

102a and 102b, an idling roller 125 is provided between the rollers 114a and 11412, which have raised peripheral portions 126a and 12611 extending around half of their peripheries. When the rollers 114a and 1141) are in the position in which they are shown in FIG. 4, a gap is provided between each of the

rollers

114a, 114b and the idling roller 125. Abutments 129a and 12% are provided below these gaps. On insertion of the stand-by web, which in the case illustrated in FIG. 4 is the web 10211, the web 102b is threaded manually between an abutment 1291). The abutments 129a and 12911 are pivotable about shafts 130a and 130k under the control of cam follower levers 131a and 13112 co-operating with cams 132a and 132b provided on the shafts which carry the

rollers

114a and 114b, When the roller 114b is rotated so that the raised portion 126b contacts the web 102b for feeding the web 102b towards the jaws 105a and 10512 the abutment 12% is pivoted in a clockwise direction, as viewed in FIG. 4, and out of the path of the web 1021;, which by means of the idling roller 125 and the raised portion 126b of the roller 11412 is fed between the spaced-apart jaws 105a and 1051).

The

webs

102a and 102b may be made of a material, or coated or impregnated with a material that becomes tacky under heat.

Alternatively, only the ends of the

webs

102a and 102b may be made of or coated or impregnated with such material. Still alternatively, the web ends may be adhesive when cold or may be coated or impregnated with an adhesive. If the adhesive or the adhesive end of the web is tacky while cold, it is not necessary to heat the jaws 105a and 105b. For coating a portion of the newly introduced web, which in the present case is the web 102b, with an adhesive, a container 136 for an adhesive (see FIG. 5) is provided having electric means 137 for heating the adhesive in the container 136. A roller 138 has an interior space 139 communicating with the interior of the container 136, a further heating element 140 being provided in the space 139 for heating the adhesive which flows from the container 136 into the space 139. The space 139 communicates with the outside of a segment 142 on the roller 138 through a plurality of ducts 143. A single revolution clutch 141 is provided for rotating the roller 138 through a single revolution alternatively in a clockwise sense, or in the opposite sense, as viewed in FIG. 4. In the present case, the web 102a is the travelling web and the roller 138 is therefore rotated in an anticlockwise direction as viewed in FIG. 4 to provide a coat of adhesive near the end of the web 102a through the ducts 143. The end of the web 10212 is then fed as described hereinbefore and is pressed by the jaws a and 1051; against the coated portion of the web 102a.

When the roller 138 is in its position shown in FIGS. 4 and 5, the ducts 143 are directed upwards to avoid leakage of the adhesive. The outermost ends of the ducts 143 are widened to form small cups in which the adhesive accumulates. The single revolution clutch 141 is connected by drive chains 144 and 145 and guide

sprockets

146, 147, 148 and 149 to the roller 138 for the adhesive while the single revolution clutch 112 is connected by

gears

150, 151, and 152 to the

shafts

107a and 107b for rotating the jaws 105a and 10512. The

clutches

112 and 141 are of similar construction and the same reference numerals have been used to indicate the components of these clutches, which will now be described in detail.

Each of the

clutches

112 and 141 comprises a disc 1 15 keyed to a shaft 156 and a coupling arm 157 pivotally mounted on the disc 155 and carrying a roller 158. The coupling arm 157 is formed with a projection 160 which is engageable in a recess 161 in a hub 162 solid with the gear wheel for coupling the shaft 156 to the gear wheel 150. A release member 164 which is pivotally mounted on wall 109 is urged by a spring 165 into a {position of abutment against a fixed abutment 167, in which it is held by a pawl 168. An electromagnet 169 is provided for releasing the pawl 168. As the disc rotates the roller 158 strikes the release member 164. The coupling arm 157 is therefore pivoted relative to the disc 155 against the action of spring 171 to remove the projection from the recess 161. When the electromagnet 169 is energized and releases the pawl 168 from the release member 164 the roller 158' is able to pivot the release member 164 against the action of spring and the projection 160 is therefore able to engage in the recess 161 to provide a drive connection.

Beyond the jaws 105a and 10512, the web 102a is guided by guide rollers 173.

FIG. 6 illustrates a modified jaw 205 which may replace the jaws 105a, 105b of the embodiment of FIGS. 4 and 5. The jaw 205 of FIG. 6 is pivotally mounted on a support 206, a tension spring 207 being connected between the jaw 205 a member 208 carrying the support 206.

A heating element 208 in the form of a flat plate is provided on the jaw 205 and can be supplied with electric current through a contact element 209 when the jaw 205 is in its rest position shown in full lines in FIG. 6. When the jaw 205 rotates from this rest position for clamping the webs together in co-operation with a similar jaw on the opposite side of the webs, the heating element 208 disengages from the stationary contact element 209 and travels substantially parallel to itself, as shown in broken lines, owing to the action of the other jaw, the jaw 205 pivoting relative to the support 206 and thereby tensioning the spring 207, until the jaw 205 and the corresponding jaw on the opposite side of the webs move away from one another sufficiently to enable the tension spring 207 to pivot the jaw 205 back to its initial position relative to the support 206.

The third embodiment of FIGS. 7 and 8 comprises reels 301a and 30111 for supplying webs 302a and 302k

past rollers

303a and 303b and through web guides 304a and 304k and cutters 308a and 3055b to jaws 310a and 31%. Drive chains 311a and 311th carry the jaws 310a and 31017 and extend around sprockets 313a, 313b, 314a, 3141) which are carried on shafts 316a 316b, 317a, and 317b journalled in side walls 318 and 319 (see also FIG. 8). An electric motor 321 is connected to a main drive shaft 322 carrying a single revolution clutch 324 which controls the transmission of drive through a gear wheel 325 on the shaft 322 to gear

wheels

326 and 327 provided on the shafts 316a and 31611 for driving the sprockets 313a and 31317. The construction of the clutch 324 is similar to that of the

clutches

112 and 141 and will therefore not be described in detail.

When the jaws 310a and 31% are in their positions shown in FIGS. 7 and 8, they are engaged at one end by resiliently mounted contact elements 330a and 330b, their other ends being electrically connected by an electrical conductor 331 which is insulated from other parts of the embodiment. The contact elements 33011, 33017 and the electrical conductor 331 serve to supply electric current to heatingelements 333a and 33311 on the jaws 310a and 31012.

The cutters 308a and 3081) are carried on arms 335a and 33512, which are connected together by a link 336, and are turnable about pivots 337a and 337b. The arms 335a and 335!) are rigid with arms 339a and 33912 which are urged towards one another by tension springs 340a and 34%. The arm 33% is pivoted to the armature of an electromagnet 342 which is operable to pivot the arm 33912 in either direction about the pivot 3371) from the position in which the arm 33% is shown in FIG. 7. When the arm 33% is pivoted clockwise about the pivot 33712 from its position shown in FIG. 7, the cutter 308B cuts the web 302a, whereas when the arm 33912 is pivoted in the opposite direction, the cutter 308a cuts the web 302a.

The shaft 317a is carried by a pair of plates 345 which are turnable about the axis of the shaft 316a.

Guide surfaces 346a and 346k on guide members 347a and 34712 extend parallel to the paths of the webs for guiding the jaws 310a and 31012 and thereby preventing turning of the plate 345 until the jaw 310a has reached the end of the guide surface 346a nearest the sprocket wheel 314a.

An electromagnet 349 controls a pawl 350 for operating the single revolution clutch 324.

Sprockets

353 and 354 and a drive chain 355 connect the main drive shaft 322 to a feed roller 357 (FIG. 8) which co-operates with a resiliently mounted guide roller 358 for feeding the web 3021) from a guide roller 359.

The

rollers

303a and 303b are formed with recesses 360a and 36012 extending partly around their peripheries and are disposed on opposite sides of a pair of rollers 361a and 361]). While the travelling web, which in the present case is the web 301b, is being fed through the device, the end of the stand-by web, Which in the present case is the web 302a, is inserted into the recess 360a between the roller 303a and the roller 361a. The roller 303a is then rotated for example manually by an operator, through one revolution, a click-stop device being provided for arresting the roller 303a after one revolution, so that a predetermined length of the web 302a is fed past the guide 304a. When the approach of the end of the web 3021: on the reel 30112 is sensed by known means (such as the feeler arms 60 of FIG. 1) electric current is passed through the heating elements 333a and 33315 by means of the contacts 330a and 330k approximately five minutes before the reel 3011) is exhausted. Thereby the jaws 310a and 31% are heated. The

electromagnets

342 and 349 are energized. Energization of the electromagnet 342 causes the cutter 3081; to cut the Web 302b. The electromagnet 349 operates the single revolution clutch 324 to provide drive to the sprocket wheels 313a and 3ll3b for three rotations of the main drive shaft 322. The jaws 310a and 31% move towards one another, press together the leading end of the web 302a and the rear end of the web 302b, and travel along the guide surfaces 346a and 3461) together with both web ends while welding the ends of the webs 302a and 3021: together. When the jaw 310a slides from the right hand end, as viewed in FIG. 7 of the guide surfaces 346a, the plates 345 are free to pivot by a small amount about the shaft 316a as the jaws 310a and 31% travel around the sprocket wheels 314a and 314b whereby to avoid jamming. When the main drive shaft 322. has completed three rotations, the jaws 310a and 31012 are again in their positions shown in FIGS. 7 and 8, and the drive to the sprocket wheels 313a and 313b terminates. The web 302a is now the travelling web and a new web, replacing the web 302b is threaded between the rollers 30317 and 36112 as the new stand-by web. Adjustment screws 363, of which only one is shown, limit the amount of pivoting of the plates 345.

Each of the above-described splicing devices may be employed to splice together webs of material such as thin sheet cellulose or other synthetic material which can be welded together under heat and pressure whereby the use of adhesive strips for joining together the ends of the webs may be avoided. The jaws travel with and in contact with the webs to ensure that the webs are securely welded together. Alternatively, a suitable glue may be provided to the web portions to be welded together. Again, if the web portions are tacky while cold the heating of the jaws may be omitted. When employing heated jaws the heat is stored in the jaws. Therefore it is not necessary to supply electric current to the jaws by means, for example, of sliding contacts or flexible cables while the jaws are movmg.

It should be clearly understood that the embodiments hereinbefore described in detail are given by way of example only. Many modifications, additions and omissions are possible without departing from the spirit of this invention.

What is claimed is:

1. A splicing device comprising pressing means, means for feeding a travelling web and the leading portion of a stand-by web between said pressing means, means for moving said pressing means towards each other to press said leading portion and a portion of said travelling web together, and displacing means comprising a swingable arm carrying said pressing means, said arm being arranged for displacing said pressing means along the path of travel of said web portions to cause said pressing means when pressing said web portions togethre to travel jointly with said web portions along the path of travel of said travelling web, whereby the entire length of said web portions are in contact with said pressing means during the travel of said pressing means along said path.

2. A splicing device comprising pressing means, means for feeding a travelling web and the leading portion of a stand-by web between said pressing means, means for moving said pressing means towards each other to press said leading portion and the portion of said travelling web together, and displacing means for causing said pressing means while pressing said web portions together, to travel jointly with said web portions along the path of travel of said travelling web, said displacing means comprising endless belts carrying said pressing means, whereby the entire length of said web portions are in contact with the pressing means during the travel of said pressing means along said path.

3. A splicing device comprising pressing means, means for feeding a travelling web and the leading portion of a stand-by web between said pressing means, pre-heating means for heating the pressing means, means for rendering the pre-heating means operative at a predetermine interval before the arrival of the trailing end of the travelling web, means for moving said pressing means towards each other to press a portion of said travelling web and said leading portion of the stand-by web together and causing said preheating means to be rendered inoperative, and displacing means for causing said pressing means while pressing said web portions together to travel jointly with said web portions along the path of travel of said travelling web, said displacing means comprising rotatable rollers carrying said pressing means, said pressing means being arranged movably relatively to the peripheries of said rollers to displace effective parts of said pressing means, 'while pressing said web portion together, in a substantially rectilinear path, whereby said web portions are spliced by welding effected by the heat stored in said travelling pressing means.

4. A splicing device as defined in claim 3, and further comprising means connecting said pressing means slidably to said rollers, and spring means urging said pressing means outwards from the peripheries of said rollers.

5. A splicing device as defined in claim 3, and further 10 comprising means for pivotally connecting said pressing means to said rollers.

6. A splicing device as defined in claim 3, and further comprising means for applying a thermally adhesive material to at least one of said web portions before the same are pressed together by said pressing means.

References Cited UNITED STATES PATENTS 2,018,907 10/1935 Wood 156--504X 2,724,426 11/1955 Bell et a1 156504X 3,089,661 5/1963 Phillips, Jr. et al. l56504X 3,305,189 2/1967 Butler, Jr. et al. 156504X ROBERT F. STAHL, Primary Examiner