| 摘要 |
1,150,322. Seaming non-metallic sheet material. A. SCHMERMUND. 31 Oct., 1966 [4 Nov., 1965], No. 46701/65. Heading B5K. [Also in Division D1] A splicing device for connecting an end portion of a travelling web to the beginning of a further web comprises means for guiding portions of the two webs between pressing means, means for sensing the end of one web, means responsive to the sensing means for moving the pressing means towards each other while pressing 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. The web portions may be made of a material, or coated or impregnated with a material, which is adhesive at normal room temperature and are connected by pressure. Alternatively, the web portions may be made of a material, or coated or impregnated with a material, which becomes adhesive under heat and in this case the pressing means are heated. In one embodiment, Fig. 1, a web 2a supplied from a reel 1a is travelling to a packing machine and a web 2b from a reel 1b is a stand-by web. The webs 2a, 2b pass over guides 4a,4b rotatable about pivots 5a, 5b and on which rollers 3a, 3b are rotatably mounted. The guides 4a, 4b also carry cutters 8a, 8b slidable in slots 17a, 17b and web retainers 9a, 9b and are provided with perforations 10a, 10b connected to a suction source (not shown). The cutters 8a, 8b are pivoted to arms 18a, 18b of two pairs of three-armed levers 19a, 19b pivotally mounted by pins 20a, 20b on projections 21a, 21b on the guides 4a, 4b and having further arms 22a, 22b, 23a, 23b. Tension springs 25a, 25b urge the cutters 8a, 8b towards a stationary counterelement 63 and tend to pivot the levers 19a, 19b about the pins 20a, 20b. The cutters 8a, 8b are retained in the position of Fig. 1 by the engagement of the arms 23a, 23b with a common pawl 27 which is pivotable against the action of a spring (62), Fig. 3 (not shown), by an electromagnet (61). Two pairs of stops 28a, 28b are pivotally mounted on the projections 21a, 21b by shafts 29a, 29b manually rotatable to engage the arms 23a, 23b to retain the levers 19a, 19b and the cutters 8a, 8b against the action of the springs 25a, 25b when the pawl 27 is released by the electromagnet (61). Curved abutments 30a, 30b are co-operable with arms 31a, 31b of the stops 28a, 28b to ensure that these stops are pivoted into their locking positions when the guides 4a, 4b are retracted. Two heating jaws 32a, 32b are each mounted on a parallelogram linkage comprising links 33a, 33b, 34a, 34b, 35a, 35b, the latter four being pivotally connected to a frame carried on an arm 52 pivotable about a shaft 53. The links 34a, 34b are linked by meshing toothed ends of arms 41a, 41b. A tension spring 42 urges the jaws 32a, 32b together but they are normally held apart by a member 44 pivoted to a lever 45 rigid with a lever 46 retained by a pawl 47. The jaws 32a, 32b are provided with heating elements 48a, 48b which in the position of Fig. I are connected to contacts 49a, 49b bearing against resilient contact arms 50a, 50b. A control device comprising contact elements 59 controlled by a feeler arm 60 is associated with each reel 1a, 1b so that each element 48a, 48b is supplied with current only shortly before the reel 1a or or 1b is exhausted. The pawl 47 is pivotally mounted on the arm 52 and releasable by energization of an electromagnet 55 through a lever 56. An abutment lever 65 is linked to the arm 52 through the lever 46 and is co-operable with a stationary abutment 66. In operation, the stand-by web 2b is manually placed in position on the guide 4b by turning this guide about the pivot 5b and the stop 28a is turned by manually turning the arm 31a from its locking position shown in Fig. 1 to its non- locking position. Turning of the guide 4b automatically turns the stop 28b into its locking position. When the arm 60 senses the approach of the end of the web 2a the contact elements 59 are closed so that the jaws 32a, 32b are heated. Subsequently, when the arm 60 senses the end of the web 2a, the electromagnets 55, (61) are energized so that the pawls 47, 27, respectively, are released. On release of the pawl 47, the spring 42 closes the jaws 32a, 32b to heat seal the webs together and the link 33a disengages the abutment 54 so that the arm 52 pivots downwards so that the jaws 32a, 32b move with the webs. When the pawl 27 is released the levers 19a, 19b are released and the web 2a is cut off by the cutter 8a. When the jaws 32a, 32b have reached the end of their travel, Fig. 2 (not shown), they are opened by the lever 65 striking the abutment 66 thus causing the pawl 47 to re-engage the arm 46. Subsequently, the arm 52 is manually returned to the position of Fig. 1 and locked by engagement of the link 33a with the abutment 54. A new stand-by web is positioned in the device. In a second embodiment, Fig. 4, a travelling web 102a and a stand-by web 102b are guided by rollers 103a, 103b, 104a, 104b, 114a, 114b and pass between jaws 105a, 105b having heating elements 111a, 111b and resiliently mounted on supports 106a, 106b pivotable about shafts 107a, 107b. When a feeler arm (not shown) detects that the web 102a is almost exhausted the elements 111a, 111b are supplied with current. When the end of the web 102a approaches the jaws 105a, 105b a single revolution clutch (112), Fig. 5 (not shown), is operated to rotate the shafts 107a, 107b through one revolution and the roller 114b is rotated to feed the web 102b towards the jaws 105a, 105b which approach each other and press the webs 102a, 102b tgoether to weld them. The jaws 105a, 105b travel with the webs and are pressed inwardly of the supports 106a, 106b and subsequently move away from each other. Cutters 115a, 115b are controlled by electromagnets 116a, 116b which operate levers 118a, 118b formed with pawls 119a, 119b engageable with levers 120a, 120b rigidly connected to levers 121a, 121b pivotally connected to these cutters which are urged towards a fixed bar 114 by springs 122a, 122b. In the position of Fig. 4, a gap is provided between each of the rollers 114a, 114b and an idling roller 125. Abutments 129a, 129b are provided below these gaps and are pivotable about shafts 130a, 130b by levers 131a, 131b having cam followers thereon which engage cams 132a, 132b on the shafts of the rollers 114a, 114b. When the roller 114b is rotated a raised portion 126b thereon feeds the web 102b between the jaws 105a, 105b, the abutment 129b being pivoted clockwise. Guide rollers 173 are provided beneath the jaws 105a, 105b. If it is necessary to coat the leading end of the web 102b with adhesive, the adhesive is fed from an electrically heated container (136), Fig. 5 (not shown), to the interior 139 of a roller 138 provided with a further heating element 140. Ducts 143 widened at their outermost ends to form small cups communicate with the outside of a segment 142 on the roller 138 and normally extend vertically upwardly to avoid leakage of the adhesive. When it is desired to apply adhesive to the web 102b the roller 138 is rotated anticlockwise of Fig. 4 by a single revolution clutch 141. In a modification, Fig. 6, the jaws 105a, 105b may each be replaced by a jaw 205 pivotally mounted on a support 206 carried by a member 208. A tension spring 207 is provided between the jaw 205 and the member 208. When the jaw 205 moves along in co-operation with another jaw with the webs clamped therebetween, a heating element 208 in the form of a flat plate disengages from a stationary contact element 209 through which it is supplied with electric current. In a third embodiment, Fig. 7, webs 302a, 302b are supplied past rollers 303a, 303b through guides 304a, 304b and cutters 308a, 308b to jaws 310a, 310b carried by chains 311a, 311b extending around sprockets 313a, 313b, 314a, 314b on shafts 316a, 316b, 317a, 317b, the shafts 316a, 316b being drivable by a single revolution clutch 324 operated by a pawl 350 controlled by an electromagnet 349. Electrically heatable elements 333a, 333b are provided in the jaws 310a, 310b. The cutters 308a, 308b are carried on arms 335a, 335b connected by a link 336, mounted on pivots 337a, 337b and rigid with arms 339a, 339b urged together by tension springs 340a, 340b. The arm 339b is pivotable either clockwise or anticlockwise by an electromagnet 342 so that the cutter 308b cuts the web 302b or the cutter 308a cuts the web 302a, respectively. The shaft 317a is carried by a pair of plates 345 which are pivotable about the shaft 316a. The jaws 310a, 310b are guided by surfaces 346a, 346b on members 347a, 347b and turning of the plates 345 is prevented until the jaw 310a has reached the end of the surface 346a nearest the sprocket 314a. Whilst the travelling web 302b is being fed through the device, the end of the stand-by web 302a is inserted into a recess 360a between the roller 303a and a roller 361a. The roller 303a is manually rotated through one revolution controlled by a stop device so that a predetermined length of the web 302a is fed past the guide 304a. When the approach of the end of the web 302b is sensed current is supplied to the elements 333a, 333b. The electromagnets 342, 349 are energized so that the cutter 308b cuts the web 302b and the clutch 324 drives the sprockets 313a, 313b to cause the jaws to clamp and weld the leading end of the web 302a and the trailing end of the web 302b together. When the jaws 310a, 310b have returned to the position shown the drive to the wheels 313a, 313b terminates. |
