US3416289A - Apparatus for wrapping cigarette packs and the like - Google Patents

Description

Dec. 17, 1968 APPARATUS FOR'WRAPPING CIGARETTE PACKS AND THE LIKE Filed July 18, 1966 5 Sheets-Sheet 1 A. SEBELIN 3,416,289

Dec. 17, 1968 A. SEBELIN 3,416,239

APPARATUS FOR WRAPPING CIGARETTE PACKS AND TH L-IKE Filed July 18, 1966 Y s Sheets-'s116653 United States Patent O 3,416,289 APPARATUS FOR WRAPPING CIGARETTE PACKS AND THE LIKE Alfred Sebelin, Hamburg-Bergedorf, Germany, assignor to Hanni-Werke Koerher & Co. KG., Hamburg-Bergedorf, Germany Filed July 18, 1966, Ser. No. 566,073 Claims priority, application Great Britain, July 19, 1965, 30,550; Dec. 21, 1965, 54,050 16 Claims. (Cl. 53-55) The present invention relates to an apparatus for wrapping cigarette packs or analogous box-shaped commodities by applying around such commodities envelopes consisting of or provided with heat-scalable material. More particularly, the invention relates to improvements in the construction, mounting and operation of one or more heat-applying elements forming part of a wrapping apparatus which is utilized to provide each of a series of preferably box-shaped commodities with an envelope consisting of or including cellophane or other transparent, translucent or opaque sheet material.

It is known to provide cirgarette packs with envelopes consisting of transparent plastic material and having overlapping or abutting portions which are sealingly secured to each other by the application of pressure and/or of heat. The sealing action can be carried out by actually lwelding the abutting or overlapping portions or aps of a suitably deformed blank so that the material of the overlapping or abutting portions melts and that such portions are actually fused to each other. Alternatively, one or both overlapping portions of an envelope can be provided with a coat of adhesive whose bonding action is accelerated by expulsion of surplus moisture or is otherwise enhanced in response to the application of pressure and/ or heat.

The means which are utilized to apply heat to overlapping or abutting portions of envelopes normally include one or more heat-applying elements in the form of plates or strips which can be heated by electric current and are movable .against and away from successive envelopes in synchronism with the operation of various folding, tucking, blank feeding and pack conveying instrumentalities which form part of a wrapping apparatus. The arrangement is normally such that the heat-applying elements engage successive envelopes during the intervals between intermittent movements of a continuous le of packs through the Wrapping apparatus, and the dwell of such elements in heat-transmitting position (i.e., the length of periods during which a heat-applying element is immediately adjacent to or in actual contact with the overlapping or abutting portions of one or more envelopes) depends on the speed of the wrapping apparatus. This is satisfactory when the Wrapping apparatus is operated at ,a normal or full speed which is calculated in such a way that the dwell of one or more heat-applying elements in heattransmitting position is just sulcient to form a satisfactory bond or seam without overheating or underheating. However, when the wrapping apparatus is operated at a speed which is less than the normal or full speed, and if the dwell of heat-applying elements in heat-transmitting position is a function `of such speed, the portions to be bonded or =welded to each other will receive too much heat with resultant burning, deformation or discoloration of lwrapper material. For example, it happens frequently that the operators must examine the functioning of one or more units in a wrapping apparatus and that the apparatus must be driven manually at a very low speed so that all stages in the operation of a given unit can be observed with the naked eye. During such low-speed manual operation of conventional wrapping apparatus, the dwell of heat-applying elements in heat-transmitting position is much longer than 'when the apparatus is driven by an electric motor or another prime mover at a relatively high normal or full lCe speed which is required to make sure that the apparatus will apply envelopes at the same rate at which the commodities to be wrapped are being supplied by one or more high-speed packaging or other producing machines.

Accordingly, it is an important object of the present invention to provide an improved wrapping apparatus for cigarette packs and similar commodities wherein the operation yof one or more heat-applying elements can be synchronized Awith the speed of the remaining movable parts of the (wrapping .apparatus but wherein the dwell of such heat-applying elements in heat-transmitting position is independent of the speed at which the various conveying, folding, tucking and other instrumentalities perform their respective functions.

Another object of the invention is to provide a wrapping apparatus of the just 'outlined characteristics wvherein the dwell of one or more heat-applying elements in their heat-transmitting position is not dependent on the speed at which the remaining movable parts of the apparatus are driven and wherein such dwell romains constant regardless of whether the remaining parts .are moved manually or by means of a motor, transmission or other prime mover.

A further object of the present invention is to provide a novel control system which takes over the regulation of dwell as soon as the wrapping apparatus begins to operate at a speed which is dierent from a predetermined full speed at which the dwell of one or more heat-applying elements can be determined by the drive of the 'wrapping apparatus.

A concomitant object of the invention is to provide a control system which takes over the regulation of dwell of one or more heat-applying elements in heat-transmitting positions as soon as the speed of the wrapping apparatus is reduced below a preselected normal or full speed.

Still another object of the invention is to provide a control system which can automatically terminate the normal motion transmitting connection between the drive of a wrapping apparatus and one or more heat-applying elements as soon as such normal connection would lengthen the period of dwell in heat-transmitting position, and to provide such control system with very simple signal generating and other components which then determine the per-iod of dwell as well as the actual distance between one or more heat-applying elements and the wrapper material when the heat-applying elements are disengaged from the portions which are to be dried, bonded, welded or otherwise connected to each other in response to the application of pressure and/or heat.

Briefly stated, one feature of my present invention resides in the provision of an apparatus for wrapping cigarette packs or analogous preferably box-shaped cornmodities in envelopes of sheet material, for example, in envelopes consisting of transparent heat-sealable synthetic themoplastic material or in envelopes consisting of transparent, translucent or opaque material having selected portions which are coated with a suitable adhesive Whose bonding action is enhanced and/or accelerated in response to the application of pressure and/or heat. In its simplest form, the wrapping apparatus comprises instrumentalities (including one or more conveyors, plungers, rams, pushers, tucking and folding mem-bers, blank feeding members and others) operative to move the commodities seriatim along a predetermined path which may be defined by a suitable system of tracks and to apply and deform blanks of sheet material around successive commodities to thus convert such blanks into envelopes each having at least two adjoining portions which may but need not actually overlap and may be secured to each other by the application of pressure and/or heat, multiple-speed drive means; for operating such instrumentalities at a plurality of speeds including a full speed and zero speed, at least one electrically or otherwise heated plate or analogous heat-applying element which is movable between a heat-transmitting rst position with reference to the adjoining portions of successive envelopes and at least one second or yretracted position, shifting means operated Iby the drive means and arranged to move the heat-applying element to its rst position with reference to successive envelopes and to maintain the element in first position for a predetermined period of time (dwell) in response to operation of the various instrumentalities at full speed, and control means comprising time-delay means or retarding means for moving the heat-applying element from rst position after elapse of such predetermined period of time in response to operation of the instrumentalities at less than full speed. In other words, the time-delay means of the control means takes over the regulation of dwell of the heat-applying element in first position when the wrapping operation is carried out at less than full speed.

In accordance with a presently preferred embodiment of my invention, the control means comprises an electric circuit wherein the time-delay means includes a relay receiving signal from a signal generating device which is responsive to changes in the speed of the drive means and which can transmit such signals through the intermediary of a lnovel starter device arranged to complete the circuit of the aforementioned relay at intervals whose frequency depends on the speed of the drive means. Such starter device may comprise an electric switch which remains open when the drive means operates at full speed but is closed by a suitable magnet as soon as the drive means operates at less than full speed.

The novel xfeatures which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved wrapping apparatus itself, however, lboth as to its construction and its mode of of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments `with reference to the accompanying drawings, in which:

FIG. 1 is a schematic fragmentary side elevation-al view of a wrapping apparatus which embodies my invention and is utilized to apply transparent envelopes around cigarette packs.

IFIG. 2 is a fragmentary top plan view of a portion of the structure shown in FIG. 1, further showing the details of a shifting mechanism serving to move a plurality of reciprocable heat-applying elements into and from heat-transmitting engagement with successive blanks which are to be converted `into envelopes, certain parts of the structure shown in FIG. 2 being illustrated in section;

FIG. 3 shows a portion of an electric control system which is utilized to regulate the dwell of heat-applying elements in heat-transmitting position when the wrapping apparatus operates at less than full speed;

FIG. 4 is a view substantially as seen in the direction of the arrow IV shown in FIG. 3;

FIG. 5 illustrates the electric circuit of the control system;

FIG. 6 illustrates a first drive for the wrapping apparatus of FIGS. 1 and 2;

FIG. 7 shows a second drive which can be utilized when the wrapping apparatus receives cigarette packs from two producing machines;

FIG. 8 illustrates a modification of the structure shown in FIG. 7; and

FIG. 9 illustrates a modilication of the structure shown n FIG. 6.

Referring to the drawings in detail, and rst to FIG. I, there is shown an apparatus for enclosing cigarette packs 4 or analogous box-shaped commodities in transparent envelopes or wrappers of heat-scalable synthetic plastic material, such as cellophane. The packs 4 come from one or more packaging or other producing machines by descending along a predetermined path in the directlon 1ndicated by an arrow 1 and enter the upper end of a chute 2 forming part of a magazine or source Whereln they form a stack of superimposed packs. The lowermost pack 4 of the stack in the chute 2 rests on -a platform 7 forming part of a composite track 6 in whlch the packs are advanced Seriatim past a plurality of blank applylng, folding, tucking and sealing instrumentalities. A suitable conveyor (not shown) comprises a series of equldlstant motion transmitting instrumentalities here illustrated as arms 46 which advance along the upper side of the platform 7 and each of which entrains the lowermost pack 4 of the stack in the chute 2 in the direction indicated by an arrow 3. Such packs move between two driven coaxial suction disks 42, 44 which serve as a means for feeding into the path of successive packs precut blanks 40, each such blank being provided with a length of tear strip which is welded thereto by means of a device shown in FIG. l at a level above the suction disks 42, 44.

The heat-scalable sheet material is stored on a reel or bobbin 12 and is withdrawn in the direction indicated by an arrow 11. The means for withdrawing the web 14 of such transparent material from the bobbin 12 comprises a driven suction drum 26 located downstream of a set of fixed guide rollers 16, 18, 20 and 22. A tensioning roller 24 which is disposed between the guide rollers 16, 18 is biased upwardly by a helical spring 24a and maintains the web 14 under requisite tension.

The tear strip stock is stored on a reel or bobbin 30 and forms a tape 28 which is trained around guide rollers 18, 20 and 22 so that it advances with the web 14. In the zone between the guide rollers 20, 22, the tape 28 is welded to the web 14 by a rst heat-applying or welding unit comprising an electrically heated heat-applying element 32 which is reciprocable against and away from the tape 28. This element 32 (as well as `three additional heatapplying elements 56, 66, 68 which will be described hereinafter) will be called a Welding element because, in the embodiments which are shown in the drawings, the web 14 and tape 28 consist of heat-scalable or weldable synthetic plastic material. The means for moving the Welding element 32 away from the tape 28 comprises a set of helical springs 36. An electromagnet 34 constitutes the means for moving the welding element 32 against the opposition of the springs 3-6. In other words, the tape 28 will be welded to the web 14 when the electromagnet 34 is energized.

The suction drum 26 cooperates with a revolving knifev 38 which severs the web 14 and tape 28 at regular intervals to form precut blanks 40 each of which comprises a rectangular sheet of transparent material forming part of the web 14 and a length of the tape 28, the latter being welded to the transparent material.

The operation of various instrumentalities including the arms 46, suction disks 42, 44, suction drum 26 and knife 38 is synchronized in such a way that the disks 42, 44 place a blank 40 into the path of a pack 4 while the pack advances with the respective motion transmitting arm 46 whereby the front panel of the pack engages an intermediate portion of the blank 40 and separates it from the peripheral surfaces of the disks 42, 44. The packs 4 which travel along the platform 7 advance through the space between the suction disks 42, 44 and thereupon move between a pair of stationary deforming or tucking members 48, S0 which tuck in two laterally extending median portions 40e of successive blanks 40 so that such median portions 40:,1 lie fiat against the adjoining lateral panels of the respective pack 4. Each such pack is then deposited onto the head of a vertically reciprocable ram 52 which is disposed at a level below a vertical duct 8 and, when the ram 52 performs an upward stroke, its upwardly extending ledge 52a folds the lower trailing edge portion 40d of the blank 40 so that such edge portion 40d overlies the rear vertical panel of the respective pack 4. At the same time, the head of the ram 52 moves the upper trailing edge portion 40e of the blank 40 along an inclined folding surface 54 provided on a second welding element 56 so that the upper trailing edge portion 40e of the blank is folded over and overlies the lower edge portion 40d which has been folded by the ledge 52a.

Movements of the ram 52 are synchronized with movements of the remaining parts of the wrapping apparatus so that the packs 4 are lifted seriatim at the same rate at which such packs advance from the chute 2 and along the platform 7.

An intermediate platform 9 at the upper end of the duct 8 serves as a guide and support for successive packs 4 during transfer from the duct 8 into a second vertical duct 10. The means for advancing the packs along the platform 9 comprises a reciprocable U-shaped plunger 58 provided with two tucking portions or prongs which tuck in the laterally extending parts of the overlapping rear edge portions 40d, 40e of blanks 40 so that such tucked-in parts lie flat against the respective lateral panels of the packs 4. Thus, when a pack 4 advances along the platform 9, the respective blank 40 is draped around its front, rear, top and bottom panels and such blank is further formed with four tucks two of which lie at against each lateral panel of the pack.

The duct 10 is disposed at a level above a vertically reciprocable U-shaped ram -64 and the platform 9 carries two stationary tucking members 60, 62 which pass along the tucks 40C formed by the members 48, 50 to insure that such tucks lie absolutely flat against the lateral panels of the respective pack. The ram 64 is provided with two upwardly extending folding ledges (corresponding to the ledge 52a of the ram 52). When the ram 64 moves upwardly, its ledges fold the lower flaps 40a of each successive blank 40. The side wall 66, 68 (see FIG. 2) of the duct 10 fold the upper flaps 40b of successive blanks 40 when the ram 64 performs an upward stroke whereby each flap 40a overlies a portion of a flap 40b as clearly shown in FIG. 1 wherein the side walls 66, 68 were broken away for clarity.

The side walls 66, 68 constitute two additional welding elements and respectively accommodate electric resistance heaters 76, 82 shown in FIG. 2. These welding elements are movable toward and away from the respective pairs of overlapping aps 40a, 40b in the same way as the welding element 56 which contains an electric resistance wire 70. Conductors 222 and 224, 72 and 74, 78 and 80, 84, 86 respectively serve to connect the electromagnet 34 and welding elements 56, 66, 68 into the electric circuit of a novel control system for the wrapping apparatus, this electric circuit being shown in FIG. 5. The welding elements 66, 68 will weld the aps 40a to the respective flaps 40b to thus complete the conversion of blanks 40 into envelopes each of which surrounds a pack 4 `and has a weldedon tear strip.

A fully wrapped pack 4 which emerges at the upper end of the duct 10 is then entrained by a suitable conveyor (not shown) and is transported to a carton lling machine or to storage.

When the wrapping apparatus is in use, the wires of the welding element 32 and the wires 70, 76, 82 of the welding elements 56, 66, 68 are connected in circuit with a source of electrical energy and the welding elements 32, 56, 66, 68 act not unlike sole plates of an electric iron. These welding elements preferably consist of a metallic material which is a good conductor of heat.

In accordance with a feature of my present invention, the welding elements 56, 66 and 68 are reciprocable or shiftable by a shifting mechanism which is shown in FIG. 2 and serves to prevent overheating and eventual burning, discoloration or disguration of blanks 40 when the wrapping apparatus is operated at full speed, i.e., at a pre- '6 selected high speed which is desirable to wrap packs 4 at the same rate at which such packs enter the chute 2 when the packaging machine or machines supplying packs to the chute 2 operate at a normal speed. When one of the packaging machines begins to operate 'at less than full Speed or comes to a halt, the speed of the wrapping apparatus must be reduced, too, whereby, were the welding elements 32, 56, 66, 68 reciprocated at a speed which is invariably synchronized with the speed of the wrapping apparatus, the heat-sealing surfaces of such welding elements would remain in longer-lasting contact with the blanks 40 as soon as the speed of the wrapping apparatus would decrease below the aforementioned full speed. In other words, burning of or other damage to envelopes can be prevented if the shifting mechanism which reciprocates the welding elements 56, 66, 68 maintains such welding elements in contact with the heat-scalable material for periods of time which are just sufficient to carry out a satisfactory welding operation but the length of such periods should not increase if the wrapping apparatus is operated at less than full speed, for example, when the apparatus is started, when its speed is reduced in response to decreasing rate of delivery of packs 4 into the chute 2, or when the persons in charge drive the apparatus manually to inspect the function of its components. An important feature of my present invention resides in the provision of a control system which takes over as soon as the wrapping apparatus operates at less than full speed, and such control system then determines the length of periods during which the welding elements 32, 56, 66, 68 remain in heat-transmitting contact with successive increments of the web 14 and tape 28 or with successive blanks 40.

Movements of the welding elements 56, 66, 68 yare timed in such a way that these elements are not in actual contact with the blanks 40 when the blanks are in motion, i.e., the heat-sealing action takes place during intervals between intermittent movements of packs 4 through the ducts 8 and 10. Each of the welding elements 56, 66, 68 assumes a rst retracted position when the ram 52 or 64 performs an upward stroke, and the welding elements are moved to heat-sealing or heat-transmitting positions during intervals between successive upward strokes of the respective rams. Also, when the wrapping apparatus is not driven at full speed, the dwell of welding elements in their heat-transmitting position is independent of the speed of the wrapping apparatus, i.e., of the length of intervals between successive upward strokes of the rams 52, 64. The duration of such dwell depends on the temperature of welding elements and on the thickness and composition of blanks 40. The means for preventing downward movement of packs 4 in the ducts 8 and 10 is not shown in the drawings. For example, the packs moving stepwise through the duct 8 can be held against downward movement (when the ram 52 performs a return stroke) by frictional engagement with a portion of the wall structure forming the duct 8 or in another suitable way.

FIG. 1 shows that the welding element 56 is high enough to engage more than a single blank at a time. Therefore, the temperature and hence the heat-sealing action of t-he welding element 56 is selected in such a way that the overlapping rear edge portions 40d, 40e of each blank 40 are sealed to each other in response to repeated heating. The same holds true for the welding of flaps 40a, 40b by the welding elements `66, 68. However, it is equally possible to select the height of welding elements 56, `66, 68 in such a way that each thereof transmits heat t0 one blank 40 at a time.

The aforementioned reciprocating or shifting mechanism for the welding elements 56, 66, 68- is shown in FIG. 2 and receives motion exclusively from the main drive shaft of the wrapping apparatus when the latter operates at full speed. The transmission ratio between the main drive shaft and the shifting mehcanism is one-to-one. The main drive shaft transmits motion to a camshaft which carries a plate cam 88. This cam has a peripheral cam face which is tracked by a roller 'follower 92 and comprises a rst section 88a having a greater radius of curvature and a second section 881) with a smaller radius of curvature. The follower 92 is mounted on an intermediate portion of a crank arm 94 one end of w-hich is rigidly secured to a crankshaft 98. The other end of the crank arm 94 is att-ached to a helical contraction spring 96 mounted on a stationary part of the -frame for the wrapping apparatus and serving as ya means for biasing the follower 92 against the face of the cam 88. When the follower 92 is free to move in response to the bias of the spring 96, the crankshaft 98 causes the welding elements 56, 66, 68 to move against the adjoining blanks 40. Such movements of the welding elements 56, 66, 68 take place in response to motion transmitted by three rack and pinion drives having a common pinion 100 attached to the camshaft 98 and meshing with three toothed racks 102, 104, 106. The rack 102 is rigid with a substantially U- shaped bar 111 which is movable back and forth in fixed bearing brackets 108, 110 and carries the welding elements 56. The rack 104 is tixed to a spindle 116 which is movable axially in brackets 112, 114 and carries a bar 118 for a head 120 connected to the welding element 66. The rack 106 is fixed to a spindle 122 which is movable axially in brackets 108, 128 and carries a bar 124 for the head 126 of the welding element 68.

The means for moving the welding elements 56, 66, 68 away from the blanks 40 independently of the section 88a on the face of the cam 88 comprises an electromagnet 130 having a reciprocable armature 130g coupled to the crank arm 94 Iand adapted to rock the shaft 98 in a -counterclockwise direction, as viewed in FIG. 2, even at a ytime when the follower 92 tracks the section 8811. The electromagnet 130, whose coil is connected with conductors 210, 212, is further utilized .as a means for moving the welding elements 56, 66, 68 to second retracted positions in which the welding elements are located .at a greater distance from the blanks 40 than in response to engagement of the follower 92 with the section 88a. This is necessary when the wrapping apparatus is arrested while the heating wires 70, 76, 82 `remain connected in circuit with -a source of electrical energy or even if the circuit of the heating wires is opened simultaneously with an interruption in operation of the welding apparatus because longer-lasting heating of stationary blanks 40l by heat radiated from the welding elements 56, 66, 68 across narrow gaps could cause damage even if the blanks are not in direct contact with the welding elements. For example, when moved to rst retracted positions in response to engagement of the follower 92 with the cam face section 88a, the welding elements 56, 66, 68 can be held at a distance of about 2 mm. from the respective blanks 40. When moved to second retracted positions in response to rocking of the crank arm 94 by the electromagnet 130, the welding elements 56, 66, 68 can be held at a distance of about 18 mm.

The aforementioned control system comprises the electromagnet 130, a starter device including a switch 136 which is shown in FIGS. 3 and 4 and a permanent magnet 134 mounted on a lever 132 affixed to the camshaft 90. The permanent magnet 134 of this starter device will close the switch 136 during each revolution of the camshaft 90 but only at such times when the wrapping apparatus operates at less than full speed. The switch 136 then causes deenergization of the electromagnet 130 (which is energized when the wrapping apparatus is arrested or operates at less than full speed) So that the spring 96 can move the follower 92 against the face of the cam 88. However, the switch 136 also energizes a time-delay relay 162 (see FIG. 5) which is deenergized after elapse of a predetermined period of time so that the dwell `of welding elements 32, 56, 66, 68 in heat-sealing or heat-transmitting position is of the same duration as when the wrapping apparatus operates at full speed, i.e., when the movements Cil of the welding elements are controlled solely by by the revolving cam 88 and .spring 96.

The switch 136 of the starter device will be closed by the permanent magnet 134 not only when the wrapping apparatus operates at a reduced speed because the prime mover of the yapparatus (to be described in connection with FIG. 6) is caused to operate at less than normal speed, but also when the prime mover is idle and the persons in charge operate the apparatus manu-ally in order to inspect the function of one or more movable instrumentalities or components, to remove a pack 4 which was stuck in the chute 2 or in one of the ducts 8, 10, or for another purpose.

The camshaft completes one full revolution for each pack 4 which is being wrapped, and the permanent magnet 134 shares such rotary movement. The switch 136 comprises a gas-filled envelope and is mounted on a carrier 142. Its envelope contains a xed contact 138 and a movable contact 140, the latter being resilient and tending to move away from the fixed contact so that the switch 136 is normally open and the starter device is ineffective. When the permanent magnet 134 approaches the switch 136 (inthe solid-line position of the carrier 142, as viewed in FIG. 3), it attracts the movable contact 140 whereby the latter engages the fixed contact 138 to close the switch. When the wrapping apparatus operates at less than full speed, the switch 136 and permanent magnet 134 serve as a means for initiating successive movement of welding elements 56, 66, 68 toward and away from the blanks 40.

The carrier 142 is axed to one arm of a two-armed lever 144 which is rockable on a lxed frame member 146. A spring biases the lever 144 to the phantom-line inoperative position of FIG. 3 in which the switch 136 is moved substantially radially of and away from the camshaft 90. In such phantom-line inoperative position of the lever 144, the switch 136 cannot be closed by the permanent magnet 134 so that this switch cannot iniiuence the movements of welding elements 56, 66, 68. The lever 144 is free to follow the bias of the spring 150 when the wrapping apparatus operates at full speed.

The means for rocking the lever 144 against the opposition of the spring 150 comprises an electromagnet 148 which also forms part of the control system. Certain additional parts of the control system are shown in the circuit diagram of FIG. 5. These parts include a relay 152 with contact 154 and a relay 156 with contacts 158, 160. The aforementioned time-delay relay 162 has an electric `motor 164 and two contacts 166, 168. The movable contact 140 of the switch 136 is connected with a conductor which is also connected to a power lead 172. The xed contact 138 of the switch 136 is connected with a second power lead 174 by means of conductors 176, 178 which are connected with the winding of the relay 152. The power leads 172, 174 are connected to the poles of a source of electrical energy (not shown).

The contact 154 of the relay 152 can connect a conductor 180 with a conductor 182. The conductor 180 is connected lwith the power lead 172 and the conductor 182 is connected with one pole of the electric motor 164. The other pole of the motor 164 is connected with the power lead 174 by a conductor 184. A further conductor 186 connects the conductor 182 with a conductor 188 which can be connected with a conductor by the contact 166 of the time-delay relay 162. The conductor 190 is also connected with the conductor 176. The other contact 168 of the time-delay relay 162 can connect the conductor 186 'with a conductor 192 which is connected with the winding of the relay 156. This winding is also connected with the power lead 174 by a conductor 194.

The contact 158 of the relay 156 can establish a currentconducting connection between conductors 196, 198 the rst of which is connected to the power lead 172. 'I'he conductor 198 can Ibe connected with a conductor 202 in response to closing of a relay contact 200. The

conductor 202 can be connected with a conductor 250 in response to closing of a manually operable switch 204. A rectifer 206 for the electromagnet 130 is connected between the conductor 250 and a further conductor 208, the latter being connected to the power lead .174. The aforementioned conductors 210, 212 connect the rectifier 206 'with the winding of the electromagnet 130. As stated before, the electromagnet 130 will be energized when the welding elements 56, 66, 68 are to be moved to second retracted positions.

The contact 160 of the relay 156 can connect two conductors 214, 216 the first of which is connected with the power lead 172. The conductor 2.16 is connected with a conductor 218 which can be connected with a conductor 228 by means of a relay contact 226. The conductor 228 is connected with the power llead 172 and the conductor 218 is connected with one terminal of a rectifier 220 for the electromagnet 34. The rectifier 220 is connected with the power lead 174 by a conductor 230 and with the electromagnet 34 by means of aforementioned conductors 222, 224. The electromagnet 34 serves to move the welding element 32 against the tape 28.

The electromagnet 148 for the two-armed lever 144 is connected with a third rectifier 236 by means of conductors 232, 234. The rectifier 236 is further connected with conductors 248, 238 the rst of which is connected rwith the power lead 246 of a second source of electrical energy. The power lead 244 of this second source is connected with a conductor 242 which can be connected with the conductor 238 in response to closing of a relay contact 240. The relay contacts 200, 226, 240 form part of a single relay whose function will be described -in connection with FIGS. 6 to 9. Alternatively, each of the contacts 200, 226, 240 can form part of a separate relay.

FIG. 6 illustrates one form of a multiple-speed drive which operates a packaging machine and the movable instrumentalities of the wrapping apparatus and which can also operate a signal generating device forming part of the control system shown in FIG. 5. The speed of the 'wrapping apparatus is synchronized with the speed of the packaging machine. The relay which replaces the relay having contacts 200, 226, 240 is shown at 330 and comprises contacts 300, 326, 340.

The prime mover of FIG. 6 is constituted by a constant speed electric motor 302 which drives a variable-speed transmission 304. A speed selector lever 306 is provided to change the speed of the output shaft 308 of the transmission 304. When the motor 302 is arrested, the output shaft 308 can be rotated by a hand wheel 316 or by an analogous actuating device. The transmission 304 can change the speed of the output shaft 308 from zero speed to a maximum speed corresponding to the full operating speed of the wrapping apparatus. A gear train 312, 314 connects the output shaft 308 with the main drive shaft 310 of the packaging machine. This main drive shaft rotates the cam-shaft 90 at the ratio of one-to-one and also transmits motion to the conveyor including the arms 46, to the rams 52, 64, to the plunger 58, to disks 42, 44 and drum 26, and to the knife 38.

The signal generating device of the control system comprises a switch 318 which closes automatically when the transmission 304 is driven at full speed but causes its movable contact 320 to move away from the fixed contact when the transmission 304 is idle or is driven at less than full speed. The switch 318 may be constituted by a centrigual switch which closes automatically in response to rotation of the main drive shaft 310 at full speed. When the switch 318 is closed, its movable contact 320 connects conductors 322, 328 the first of which is connected with a first power lead 324. The conductor 328 is connected with the winding of the relay 330. This winding is connected with a second power lead 334 by means of a further conductor 332. The power leads 324, 334 are connected with the poles of a source of electrical energy and with the conductors 336, 338 of the electric motor 302.

10 The contacts 300, 326, 340 of the relay 330 are functional equivalents of the relay contacts 200, 226, 240 shown in FIG. 5.

FIG. 7 illustrates the electric circuit of a battery of two packaging or producing machines 442, 444 whose output is fed to the chute 2 of FIG. 1. The packaging machine 442 is driven by an electric motor 446 which is connected in circuit with two power leads 424, 434 by means of conductors 448, 450. This circuit can be completed in response to closing of a master switch 452 in the conductor 450.

The packaging machine 444 is driven by an electric motor 454 which is connected with the power leads 424, 434 by conductors 456, 458. The latter conductor contains a master switch 460 which is closed in order to start the machine 444.

The packaging machines 442, 444 are respectively associated with detectors 462, 464 which scan the packs 4 issuing from the respective machine and can produce impulses when the respective machine ceases to discharge such packs or delivers packs at a reduced rate. Such impulses are utilized to reduce the speed of the wrapping apparatus or to fully arrest the wrapping apparatus, depending upon 'whether one or both packaging machines 442, 444 cease to deliver cigarette packs. The detector 462 is shown in the form of a rockable trip which extends into the path of cigarette packs 4 and is permitted to assume the position shown in FIG. 7 when the machine 442 ceases to deliver cigarette packs. The detector 462 then opens a switch 466. The other detector 464 is mounted in the same way and can open a switch 468. FIG. 7 shows the detector 464 in raised position because the sensing portion of this detector rests on a cigarette pack 4', therefore, the switch 468 is closed.

The switch 468 can connect two conductors 470, 472 the former of which is connected with the conductor 458. The conductor 472 is connected with a conductor 474 when the switch 466 is closed by the detector 462. The winding of a relay 476 is connected with the conductor 474 and with a further conductor 478 which is connected with the power lead 424. Thus, the relay 476 is energized in response to closing of the switches 466, 468, and this relay comprises two contacts 480, 482. The function of the relay 476 is to effect operation of the wrapping apparatus at full speed (when the switches 466, 468 are closed) or at half speed (when one of the switches 466, 468 is open). The contacts 480, 482 are connected in the circuit of a prime mover here shown as an electric motor 402. The contact 482 can connect a conductor 486 with a conductor 484 and with the power lead 434. The conductor 486 can be connected with a rst conductor 498 of the motor 402 by a rst contact 488 of a manually operable switch 490. The switch 490 serves as a means for starting or arresting the motor 402 at the will of the operator. The contact 480 of the relay 476 can connect the conductor 484 with a conductor 494, and the conductor 494 can be connected with a second conductor 499 of the motor 402 by a second contact 492 of the manually operable switch 490.

'Ihe motor 402 may be of the type known as a polechangeable short-circuit rotor motor which can be driven at two speeds. When it is driven at a first speed, the circuit of the motor 402 is completed through conductors 496 and 498. When driven at a second speed, the circuit of this motor is completed through the conductors 496, 499. The conductor 496 is connected directly to the power lead 424.

The output shaft 408 of the motor 402 is connected with the main drive shaft 410 of the wrapping apparatus by a gear train 412, 414. This output shaft 408 is also rotatable by `a hand wheel 416. The main drive shaft 410 controls a signal generating device here shown as a centrifugal switch 418 and connected in circuit with `a relay 430 corresponding to the relay 330 of FIG. 6 and having contacts 400, 426, 440. The winding of the relay 430 is connected with two conductors 478, 432 the latter of which is connected to the power lead 434. The conductor 428 can be connected with a conductor 422 in response to closing of the movable contact 420 of the centrifugal switch 418. The conductor 422 is connected with the power lead 424. The switch 418 will be closed only when the motor 402 operates at the higher of two speeds, i.e., when the switches 466, 468 are closed. The switch 418 will open when the motor 402 is idle or operates at the lesser of two speeds.

The main drive shaft 410 performs the same functions as the main drive shaft 310, i.e., it can drive various instrumentalities of the wrapping apparatus at a full speed (switches 466, 468 closed), at a lesser speed (one of the switches 466, 468 open), at zero speed (switches 466, 468 open and/or switch 490 open), and at one or more additional speeds (when the operator rotates the hand wheel 416).

FIG. 8 shows certain details of a circuit which constitutes a modification of the circuit shown in FIG. 7. The relay 576 which replaces the relays 430 and 476 of FIG. 7 has ve contacts 500, 526, 540 (corresponding to the contacts 200, 226, 240) and 580, 582 (corresponding to the contacts 480, 482). The winding of the relay 576 is connected with conductors S74 and 578 which correspond to the conductors 474, 478. The circuit of FIG. 8 further comprises two detectors 562, 564 (see FIG. 7) which correspond to the detectors 462, 464. The circuits of the two packaging machines (not shown in FIG. 8) are identical with those shown in FIG. 7. For convenience, the switches 566, 568 which are respectively controlled by detectors 562, 564 are also shown in FIG. 7.

In the embodiment of FIG. 8, the detectors 562, 564 replace the centrifugal switch 418, The output shaft 508 of the electric motor 502 (corresponding to the motor 402 of FIG. 7) rotates the main drive shaft 510 of the wrapping apparatus through the intermediary of a gear train 512, 514. The output shaft 508 is also rotatable by means of a hand wheel 516.

The contacts S80, 582 serve to change the speed of the motor 502 in the same way as described in connection with FIG. 7, and the conductors 574, 578, 584, 586, 594, 596, 598, 599 and power leads 524, 534 respectively correspond to similarly numbered conductors and leads shown in FIG. 7.

The manually operable switch S90 of FIG. 8 has three contacts 588, 591, 592. This switch 590 can be employed to arrest the motor 502 whenever an operator so desires. The contact 591 of the switch 590 can connect the conductor 596 with the power lead 524.

In FIG. 9, the main drive shaft 610 of the wrapping apparatus can be rotated by a gear train 612, 614 receiving motion from the output shaft 608 of a variable speed transmission 604 which is driven by a constant speed motor 602. The output shaft 608 is also rotatable by a hand wheel 616 and the speed of the transmision 604 can be varied by a selector lever 606. The motor 602 is connected to power leads 624, 634 by conductors 636, 638. The lever 606 can close a signal generating switch 618 when the main drive shaft 610 is rotated at full speed. The movable contact 620 of the switch 618 then connects a conductor 622 (connected to the power lead 634) with a conductor 628 which is connected with the winding of a relay 630 having contacts 600, 626, I640 corresponding to the contacts 200, 226, 240 shown in FIG. 5. A further conductor 632 connects the winding of the relay 630 with the power lead 624. It will he seen that the embodiment of FIG. 9 is similar to the embodiment of FIG. 6 with the exception that the switch 618 is directly controlled by the transmission 604, i.e., by the selector lever 606 which is rocked all the way against a fixed stop 606a when the output shaft 608 is rotated at full speed whereby the lever 606 automatically closes the switch 618.

The operation of 'the improved wrapping apparatus is as follows:

The manner in which the various instrumentalities shown in FIGS. 1 and 2 supply the packs 4, web 14 and tape 28 is Well known from the art and by itself forms no part of my invention. It is also known to move the welding elements 32, 56, 66, 68 toward and away from the web 28 and blanks 40 in synchronism with the operation of the various tucking, folding and conveying parts. My present invention is mainly concerned with the control system which insures that the welding elements are moved to and from heat-transmitting positions in synchronism with the operation of my wrapping apparatus only when the latter operates 'at full speed and that the main drive shaft of the welding apparatus does not determine the length of dwell of such weldin g elements in heat-transmitting position when the wrapping apparatus is driven at less than full speed, either by the prime mover or by hand.

If the prime mover of the wrapping apparatus shown in FIGS. 1 and 2 is constituted by the constant speed motor 302 of FIG. 6, the wrapping apparatus will function as follows: The speed of the output shaft 308 (and hence the speed of the main drive shaft 310 which transmits motion to the camshaft of FIGS. 2 4) can be reduced by the selector lever 306 of the variable speed transmission 304. Such reduction in speed of the output shaft 308 also includes complete stoppage of the motor 302. The centrifugal switch 318 opens automatically as soon as the main drive shaft 310 begins to rotate at less than full speed and its movable contact 320 interrupts the ow of electric current between the conductors 322 and 328. This deenergizes the relay 330 whereby the contacts 300, 326, 340 assume the positions shown in FIG. 6 and corresponding to the positions of the relay contacts 200, 226, 240 shown in FIG. 5. In other words, the contacts 300, 340 close and the contact 326 opens. The same condition of the control system is shown in FIG. 5 wherein the contact 226 is open but the contacts 200, 240 are closed. Opening of the contact 226 results in deenergization of the electromagnet 34 so that the spring 36 (FIG. l) are free to move the welding element 32 to retracted position. The contact 200 connects the conductor 198 with the conductor 202 so that the circuit of the electromagnet i's completed through the contact 158 of the relay 156. The switch 204 is closed. Energization of the electromagnet 130 results in movement of welding elements 56, 66, 68 to their second retracted positions in which the electrodes 56, 66, 68 and held at a maximum distance from the respective blanks 40. rIhe contact 240 completes the circuit of the electromagnet 148 so that the latter rocks the lever 144 (FIG. 3) from the phantom-line inoperative position to the solid-line operative position whereby the movable contact of the switch 136 is sufficiently close to the lever 132 to engage the -fixed contact 138 when the permanent magnet 134 reaches the angular position shown in FIG. 3.

It is now assumed that the speed of the transmission 304 shown in FIG. 6 has `been reduced to zero and that the operator begins to rotate the hand wheel 316 which rotates the main drive shaft 310 (and the camshaft 90) through the intermediary of the gear train 312, 3114. During each such manually induced revolution of the camshaft 90, the permanent magnet 134 approaches and moves past the switch 136 and moves the contact 140 against the fixed contact 138 to close the switoh 136. This completes the circuit of the relay 152 through the conductors 170, 176, 178 so that the relay 152 is energized and its contact 154 connects the conductor 180 with the conductor 182. The motor 164 of the time-delay relay 162 is started lbecause its circuit is completed through the conductors 180, 182, 184. The relay contact 166 connects the conductors 188, and the relay contact 168 connects the conductors 186, 192. Movement of the contact 168 to the position shown in FIG. 5 completes the circuit of the relay 156 which is energized as soon as its winding is connected with the power leads 172, 174 by means of conductors 194, 192, 186, 182, 180i and relay contacts 154, 168. The contact 166 of the time-delay relay 162 maintains the relay 152 in energized condition, i.e., the contact 154 is closed so that the circuit of the motor 164 remains completed and the relay 156 remains energized. The contact 160 of the relay 156 completes the circuit of the electromagnet 34 by bypassing the open relay contact 226 so that the electromagnet 34 moves the welding element 32 to operative position. The contact 158 of the relay 156 opens and deenergizes the electromagnet 1310 so that the spring 96 (FIG. 2) is free to contract and returns the follower 92 into engagement with the face of the cam 88. Of course, the camshaft 90 is rotated at less than full speed because the wheel 316 is rotated by hand. The follower 92 engages the section 88h of the face on the `cam 88 and the welding elements 56, 66, 68 move against the respective blanks 40 to perform a heat-sealing operation.

The time-delay relay 162 prevents the welding elements 32, 56, 66, 68 yfrom remaining in heat-transmitting positions for periods of time which are longer than the periods of dwell when the wrapping apparatus operates at full speed. When the time required for completion of a satisfactory heat-sealing operation has elapsed, the motor 164 of the time-delay relay 162 moves the contact 168 to open position. This deenergizes the relay 156 whose contact 160 opens the circuit of the electromagnet 34 so that the welding element 32 is retracted by the springs 36. The contact 160 of the relay 156 simultaneously completes the circuit of the electromagnet 130 which is energized and moves the follower 92 away from the cam 88 so that the welding elements 56, 66, 68 are moved to their second retracted positions. The motor 162 also moves the contact 166 to open position to thereby deenengize the relay 152 by disconnecting the conductor 190 from the conductor 188. The motor 164 then returns to its initial position in which it remains until the starter switch 136 is again closed by the electromagnet 134. This completes a full cycle in the operation of the wrapping apparatus and the next cycle begins when the permanent magnet 134 again approaches the carrier 142 to close the switch 136.

If the operator releases the hand wheel 316 of FIG. 6 in such angular position that the permanent magnet 134 comes to a halt in a position in which it is immediately adjacent to the starter switch 136, the control system will again operate in a manner as -described above. The relay 152 then remains energized because its circuit is completed by the starter switch 136. Therefore, the contact 154 completes the circuit of the motor 164 and the latter maintains the contacts.166, 168 of the time-delay relay 162 in open positions until after the permanent magnet 134 move-s away from the movable contact 140 and the starter switch 136 opens. Since the contacts 166, 168 are open, the electromagnet 34 is deenergized and the electromagnet 1310 is energized so that the welding elements 32, 56, 66, 68 automatically remain in fully retracted positions. In other words, lthe materia-l of the tape 28 (welding element 32) and the blanks `40 which are adjacent to the welding elements 56, 66, 68 cannot be subjected to excessive temperatures.

The operation of the control system shown in FIG. 5 is clearly analogous if the prime mover 302 of FIG. 6 is replaced by the prime mover 602 of FIG. 9. As soon as the operator moves the selector lever 606 away from the stop 606a, i.e., as soon as the speed of the wrapping apparatus is reduced below its full speed, the switch 618 opens and the contacts 600, 626, 640 of the relay 630 assume positions shown in FIG. 9 and corresponding to the positions of relay contacts 200, 226, 240 shown in FIG. 5.

If the control system of FIG. 5 includes the relay 430 of FIG. 7, the switch 418 opens as soon as the motor 402 is arrested or as soon las the speed of this motor is reduced to the lesser of its two speeds. Such reduction in the speed of the motor 402 will take place when one of the detectors 462, 464 opens the respective switches 466, 468. As stated before, the motor 402 can be arrested by means of the manually operable switch 490. Opening of the switch 418 causes the relay contacts 400, 440 to close and the relay contact 426 to open. From then on, the control system operates in the same way as described in connection with FIG. 5, i.e., the time-delay relay 162 takes over and determines the duration of dwell of welding elements 32, 56, 66, 68 in their heat-transmitting positions. It will be readily understood that the operation of the control system is not affected by the fact that the switch 418 can open in response to manual operation of the switch 490 or in response to automatic opening of one of the switches 466, 468 by the respective detector 462, 464. The switch 466 or 468 will open if the operator decides to arrest the respective packaging machine (422 or 444) or if the respective machine fails to operate properly and reduces its output or ceases to deliver any cigarette packs.

If the control system of FIG. 5 includes the relay 576 of FIG. 8, it takes over the control of movements of the four welding elements 32, 56, 66, 68 when the motor 502 is arrested in response to manual operation of the switch 590 or when the one or the other detector (562, 564 shown in FIG. 7) opens the respective switch 566, 568. The relay 576 then closes its contacts 500, 540 and opens the contact 526.

It is to be understood that the Wrapping apparatus and the control system of my invention can be utilized with equal advantage for wrapping of cigarette packs 4 or analogous commodities in envelopes which are not provided with tear strips. The construction of the apparatus shown in FIG. 1 is then simplified because the welding element 32 and the electromagnet 34 can be omitted. Also, the shifting mechanism of FIG. 2 may be replaced by a mechanism wherein the welding elements 56, 66, 68 are movable by electromagnets or by hydraulic or pneumatic cylinder and piston units. The crank arm 94 or the cam 88 then controls one or more electric switches or valves which regulate the operation of such electromagnets or cylinder and piston units.

Furthermore, the electric control system of FIG. 5 may be replaced by a hydraulic, pneumatic or mechanical control system. All that counts is to insure that the dwell of welding elements in their heat-transmitting positions takes up the same amount of time when the wrapping apparatus operates at full speed or at a speed which is less than such full speed.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specic aspects of my contribution to the art and, therefore, such adaptions should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by I etters Patent is:

1. In an apparatus for wrapping cigarette packs and analogous commodities in envelopes of sheet material, in combination,va plurality of instrumentalities operative to move the commodities seriatim along a predetermined path and to apply and deform blanks of sheet material around successive commodities to convert such blanks into envelopes each having at least two adjoining portions which can be secured to each other by the application of heat; multiple-speed drive means for operating said instrumentalities at a plurality of speeds including a full speed; at least one heat-applying element movable between a heat-transmitting first position with reference to said adjoining portions of successive envelopes and at least one retracted second position; shifting means operated by said drive means and arranged to move said element to rst position with reference to successive envelopes and to maintain said element in such first position for a predetermined period of time in response to operation of said instrumentalities at said full speed; and control means comprising time-delay means for moving said element from rst position to second Iposition after elapse of said predetermined period of time in response to operation of said instrumentalities at less than said full speed.

2. A structure as set forth in claim 1, wherein said control means further comprises starter means for said time-delay means, said starter means being operative in response to a reduction in the speed of said instrumentalities below said full speed.

3. A structure as set forth in claim 2, wherein said starter means comprises a component which is movable between an operative position and an idle position and said control means further comprises signal generating means arranged to effect movement of said component to operative position in response to a change in the speed of said drive means to operate said instrumentalities at less than full speed.

4. A structure as set forth in claim 2, wherein said control means further comprises signal generating means for said starter means and said drive means comprises manually operable speed selector means arranged to operate said starter means through the intermediary of said signal generating means simultaneously with adjustments in the speed of said drive means.

5. A structure as set forth in claim 2, wherein said control means further comprises signal generating means for said starter means and said drive means comprises a rotary member whose rotational speed is proportional to the speed of said instrumentalities, said rotary member being arranged to operate said starter means isl responsive to a reductionin the speed of said instrumentalities below said full speed.

6. A structure as set forth in claim 2, further comprising at least one producing machine for delivering commodities to said instrumentalities at different rates, said control means further comprising signal generating means for said starter means and said signal generating means comprising detector means for determining the rate of delivery of such commodities by said producing machine and for operating said starter means through the intermediary of said signal generating means when the rate of delivery decreases below such rate as is necessary for operation of said instrumentalities at full speed.

7. A structure as set forth in claim 2, further comprising at least one producing machine for delivering commodities to said instrumentalities at different rates, said drive means comprising means for operating said machine at said plurality of speeds so that the operation of said instrumentalities is synchronized with the operation of said machine, said control means further comprising signal generating means for said starter means and responsive to changes in the speed of said machine to operate said starter means in response to a reduction in the speed of said machine below full speed.

8. A structure as set forth in claim 3, wherein said component is a normally open electric switch and said starter means further comprises means for moving said switch from said idle position to said operative position in response to a reduction in the speed of said instrumentalities below said full speed, and means for closing said switch at intervals dependent on the speed of said instrumentalities when the switch is moved to said operative position.

9. A structure as set forth in claim 8, wherein said switch comprises rst contact means and second contact means movable into engagement with said first contact means in response to the action of a magnetic force, said switch closing means comprising a magnet driven lby said drive means and arranged to move said second contact means against said rst contact means at intervals whose length Varies with the speed of said instrumentalities.

10. A structure as set forth in claim 9, wherein the means for moving said switch comprises a carrier supportingly connected with said switch and movable therewith between said operative and idle positions, resilient means for permanently biasing said carrier to idle position, and a device for moving said carrier to operative position in response to a reduction in the speed of said instrumentalities below said full speed.

11. A structure as set forth in claim 10, wherein said device comprises signal generating means responsive to changes in the speed of said drive means and electromagnet means energizable in response to signals produced by said signal generating means when the speed of said instrumentalities is reduced below said full speed to thereby move said carrier to operative position.

12. A structure as set forth in claim 1, wherein said time-delay means comprises a relay and said control means comprises an electric circuit including said relay and further including signal generating means for energizing said relay in response to a reduction in the speed of said instrumentalities below said full speed.

13. A structure as set forth in claim 1, further cornprising means for providing each of said blanks with a tear strip of heat-sealable material, a further heat-applying element movable between a heat-transmitting first position with reference to the tear strips of successive blanks and at least one retracted second position, and a device for moving said additional element to said first position and for maintaining said additional element in such first position for a preselected period of time in response to operation of said instrumentalities at full speed, said control means further comprising means for maintaining said additional element in the first position for said preselected periods of time when said instrumentalities are operated at less than said full speed.

14. A structure as set forth in claim 13, wherein said device comprises an electromagnet which is energized when said additional heat-applying element is held in said rst position thereof.

15. A structure as set forth in claim 1, comprising a plurality of heat-applyin g elements each arranged to secure a separate pair of adjoining blank portions to each other in response to movement into said rst position thereof, said shifting means comprising devices for simultaneously moving said elements between first and second positions.

16. A structure as set forth in claim 1, wherein said control means comprises an electric circuit including relay means whose condition of energization is changed in response to operation of said instrumentalities at less than full speed.

References Cited UNITED STATES PATENTS 4/1961 Brook et al. 5.3-74

5/1966 Cross et al. 53-55 U.S. Cl. X.R. 53-64, 133

Claims (1)

1. IN AN APPARATUS FOR WRAPPING CIGARETTE PACKS AND ANALOGOUS COMMODITIES IN ENVELOPES OF SHEET MATERIAL, IN COMBINATION, A PLURALITY OF INSTRUMENTALITIES OPERATIVE TO MOVE THE COMMODITIES SERIATIM ALONG A PREDETERMINED PATH AND TO APPLY AND DEFORM BLANKS OF SHEET MATERIAL AROUND SUCCESSIVE COMMODITIES TO CIVERTD SUCH BLANKS INTO ENVELOPES EACH HAVING AT LEAST TWO ADJOINING PORTIONS WHICH CAN BE SECURED TO EACH OTHER BY THE APPLICATION OF HEAT; MULTIPLE-SPEED DRIVE MEANS FOR OPERATING SAID INSTRUMENTALITIES AT A PLURALITY OF SPEEDS INCLUDING A FULL SPEED; AT LEAST ONE HEAT-APPLYING ELEMENT MOVABLE BETWEEN A HEAT-TRANSMITTING FIRST POSITION WITH REFERENCE TO SAID ADJOINING PORTIONS OF SUCCESIVE ENVELOPES AND AT LEAST ONE RETRACTED SECOND POSITION; SHIFTING MEANS OPERATED BY SAID DRIVE MEANS, AND ARRANGED TO MOVE FIRST POSITION MENT TO FIRST POSITION WITH REFERENCE TO SUCCESSIVE ENVELOPES AND TO MAINTAIN SAID ELEMENT IN SUCH FIRST POSITION FOR A PREDETERMINED PERIOD OF TIME IN RESPONSE TO OPERATION OF SAID INSTRUMENTALITIES AT SAID FULL SPEED; AND CON TROL MEANS COMPRISING TIME-DELAY MEANS FOR MOVING SAID ELEMENT FROM FIRST POSITION TO SECOND POSITION AFTER ELAPSE OF SAID PREDETERMINED PERIOD OF TIME IN RESPONSE TO OPERATION OF SAID INSTRUMENTALITIES AT LESS THAN SAID FULL SPEED.

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