Abstract:
A multiple imprint transfer tape marking device, which will imprint a multiplicity of imprint surfaces, substantially simultaneously. 
     The imprint marking device includes a plurality of laterally aligned, individually powered marker heads which are adjustably positioned for cyclically imprinting a packaging film movable along an imprint path, normal to the laterally aligned marking heads. The imprint marking device further provides a transfer tape assembly pivotally adjustable to a suitable angle relative to the aligned marker heads to provide a proportioned width of the tape for individual use by each of the marker heads. The tape assembly is provided with an automatic tape advance mechanism and is arranged to accept various width transfer tapes selected in accordance with the number of marker heads utilized and the size of the imprint indicia.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a marking apparatus for use with transfer tape and more particularly to a multiple imprint marking apparatus having individually powered marker heads which are adjustably positioned to imprint a variety of packaging films. 
     2. Prior Art 
     Most present day marking equipment used to imprint packaging films or the like with current information, such as date coding or pricing, provide machines which utilizes a transfer tape in which pigmentation is transferred to an imprinting surface by means of pressure and/or heat. While such tape provides an excellent imprint, it has the disadvantage in that once an area of the tape has been used for imprint, the pigmentation is removed and this area may not be reused. Accordingly, after each imprint cycle the tape must be advanced to provide a fresh new area for each subsequent impression that is to be made. 
     Machines using this tape provide a marker head which is supported in a frame for reciprocative movement relative to an imprint surface whereby a printing block, equipped with raised indicia, strikes the tape to apply the imprint to the imprint surface, positioned immediately adjacent the transfer tape in synchronism with a stop and go movement of the imprint surface. The marker head, which often includes a heating block is attached to a carriage for reciprocative movement along a pair of guides supported on the frame. The carriage is usually moved by means of an actuator slide having a curved cam slot therein with operative engagement with a follower carried by the carriage. Thus, as the slide is moved back and forth by means of a fluid cylinder the cam slot and follower are effective to impart the imprint motion to the marker head. While these devices have been extremely successful, they are not readily adaptable to provide multiple impressions as is desirable when sheet packaging material is utilized providing a series of side-by-side packaging film areas. Heretofore a pair of independent marking devices have been utilized each of which are supported and operable independently of the other. This arrangement has not been entirely satisfactory because of excessive costs, space requirements and complex mounting and control arrangements needed. 
     Attempts have been made to produce simultaneous impressions on packing film with the use of a single unit providing a pair of marker heads carried on a common carriage and actuated by a single power means. These devices however, have proved difficult to adjust and to position the heads when working with varying width packaging films resulting in poor impressions and often faulty register of the imprint on the generally limited size imprint area frequently provided. Further, since the transfer tape must provide independent tracks for each marker head, it proved necessary to skew the entire marking apparatus relative to the path of travel of the packaging film, which further complicates the registering adjustment of the marker heads to &#34;square&#34; the indicia with the film. Slight misalignment or faulty adjustment will accordingly produce a defective impression which is exceedingly serious since these marking devices apply important last minute information such as pricing, dating or other coding to a packaged product. 
     Further, when more than two side-by-side film packaging areas are utilized with a roll of packaging film, proper adjustment and positioning of the marker heads to provide good register and uniform impression density is virtually unattainable. 
     It would therefore be a decided advance in the state of the art to provide a fully adjustable multiple head imprinting device utilizing a transfer tape to imprint various side-by-side packaging areas generally simultaneously along a length of a packaging film. 
     SUMMARY OF THE INVENTION 
     My invention overcomes the disadvantages and difficulties associated with the prior art and provides such an adjustable multiple head imprinting device which produces a plurality of aligned imprints to be made on a product film movable past the marking device prior to a packaging operation. This is accomplished with independently powered marker heads which are fully and easily adjustable for producing unusually clear imprints in designated areas along the product film with independent adjustment of the transfer tape assembly to provide discrete sections or width portions of the tape for use by each of the marker heads without tape waste or overlapping. 
     The marker heads are adjustably positioned along a support frame in a laterally aligned orientation relative to one another and extending perpendicular to a packaging film which is movable along an imprint path through the imprint device. Two, three or more marker heads may be utilized and mounted on the frame in suitable spaced relationships relative to one another to multiply imprint certain aligned, predesignated imprint locations along the width of the packaging film. Each of the independently powered marker heads, being &#34;square&#34; with the product film is easily adjusted to provide a perfect imprint at each imprint location. The marker heads are each individually powered by a compact, short stroke fluid cylinder which is connected directly to a movable imprint member. 
     The multiple imprinter further provides an adjustable transfer tape assembly which accepts various width transfer tapes, selected in accordance with the number of marking heads utilized and with the size of the indicia required. Herein, the entire transfer tape assembly is pivotably adjusted on the imprint device relative to the marker heads whereby an individual width portion of the tape is made available to each of the marker heads without waste or &#34;strike overs.&#34; 
     It is therefore a general object of this invention to provide a multiple imprint marking device for use with transfer tape which is adapted for use with a wide variety of packaging films. 
     It is more specific object of this invention to provide independent power actuation for each of a plurality of marker heads with individual adjustment provided therefor to produce sharp clear impressions on a packaging film at predesignated aligned imprint areas. 
     It is another object of this invention to provide a multiple imprinting device having a plurality of laterally aligned, individually powered marker heads which are positioned for cyclically imprinting a packaging film movable along an imprint path, normal to the laterally aligned marker heads. 
     It is another more specific object of this invention to provide multiple imprinting device for use with transfer tape in which the transfer tape is pivotably adjustable relative to a plurality of laterally aligned marker heads to provide individual width portions of the transfer tape for each of the marker heads. 
     Other objects,, features and advantages of the invention will be readily apparent from the following description of several embodiments thereof, taken in conjunction with the accompanying drawings although variations and modifications may be effected without departing from the spirit and scope of the noval concepts of the disclosure. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view of a multiple imprinting device constructed in accordance with the principles of this invention; 
     FIG. 2 is an end elevational view of the imprinting device of FIG. 1; 
     FIG. 3 is a top plan view of the imprinting device of FIG. 1; 
     FIG. 4 is a sectional view taken generally along the line IV--IV of FIG. 3; 
     FIG. 5 is a fragmentary elevational view of the transfer tape advance mechanism; and 
     FIGS. 6-11 are diagrammatic illustrations of various embodiments of the present invention showing the adjustment of the transfer tape in relationship to the number, spacing and indicia size of the marker heads of this invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As shown in FIG. 1, 20 generally designates a multiple imprint marking device for use with a transfer tape 22 which is positioned for use to mark a film 23 utilized in a packaging operation. The packaging film 23 is diagrammatically shown in FIG. 4 as moving from a supply reel 24 to a take-up reel 25 in a stop and go movement as is conventionally provided in packaging operation, through the marking device 20. As will be readily apparent to those skilled in the art of the particular details of the packaging operation are of no importance to this invention since the invention is equally utilizable in a wide variety of embodiments for marking items other than rolls of film, such as, for example, bags, boxes, or strip material and the like. Generally, the multiple marking device 20 of this invention is useful wherever a flow of articles to be imprinted can be brought to move past a working station and wherein it is desiraable to simultaneously imprint a plurality of aligned and spaced apart marks as best seen in FIG. 3. A support arm 26 is provided to position the marking device 20 relative to the packaging film 23 for imprinting predetermined groups of imprint areas, spaced transversely across the width of the packaging film 23. 
     As best seen in FIGS. 1 and 3, the multiple imprint marking device comprises an elongated frame 28 which is attached to the support arm 26 and which extends laterally across the width of the film 23. The frame 28 provides a mount for adjustably supporting a plurality of marking head assemblies 30 in alignment relative to one another and being perpendicular to the packaging film path of movement designated by arrow 36 in FIG. 3. Each of the marking head assemblies 30 include a powered striker 32 and a marking head 34 which are independently adjustable on the elongated frame 28 to position each of the marking head assemblies 30 at a predesignated location relative to the packaging film 23 in order to simultaneously imprint the series of aligned imprint areas in synchronism with the stop and go movement of the film 23 associated with the packaging operation. 
     Each of the powered strikers 32 includes a clamping assembly 38 fixedly securable along a guide rail 40 of the elongated frame 28 by means of position locking screws 42 and includes a reciprocable anvil 44 carried by a carriage 46 guidably supported on a pair of guide pins 48 downwardly extending from the clamping assembly 38. A double acting short stroke power cylinders 50, supported by the clamping assembly 38 is provided to reciprocably strike the anvil 44 when actuated against a related marker head 34 with the film 23 and transfer tape 22 interposed therebetween. 
     A control valve 52, shown diagrammatically in FIG. 1, is appropriately activated by a suitable signal generated relative to the packaging operation (not detailed) to control the reciprocable movements of the powered strikers 32. 
     The marker heads 34 which are each independently adjustable to coincide with relative imprint areas on the packaging film 23 as best seen in FIG. 4, are secured in position between a pair of spaced guide rails 56 extending across the lower portion of the elongated frame 28, by means of clamping screws 54. The guide rails 56 insure that each of the marker heads 34 is held &#34;square&#34; relative to the packaging film 23 and provides an accurate yet simple adjustment to exactly position the marker heads 34. The marker heads 34 normally include a heated block 57 and a removable printing block member 58 having raised indicia 60 providing the required imprint information formed thereon. The raised indicia 60 which upon heating by the block 57 and striking the tape 22 will transfer pigmentation from the tape to the imprint areas associated with each discrete packaging portion of the film 23. Since the film is generally preprinted and only limited specific locations are allocated on each of the packaging portions of the film, it becomes obvious why adjustability and positioning of the indicia becomes so important to a successful packaging operation in which last minute information must be imprinted on each packaging portion of the film 23. 
     While the anvils 44 are shown as carried by the powered strikers 32 and the raised indicia 60 are positioned relative thereto on the elongated frame 28, in some instances it may be advantageous to reverse the position of these elements. 
     As illustrated in FIGS. 1 and 3, the imprint marking device 20 includes a transfer tape assembly 64 for positioning and advancing the tape 22 in a prescribed manner. The transfer tape assembly 64 comprises a transfer tape frame 66 which is pivotally attached to the elongated frame 28 for angular adjustment relative thereto and which in turn rotatably supports a transfer tape supply reel 68 and a take-up reel 69 and a tape advance mechanism 70. Further, a series of guide rollers 72 are provided on the transfer tape assembly 64 to direct a span of the transfer tape 22 between the printing block member 58 and the anvil 44 for generally angled lateral movement relative to the packaging film 23 which is advanced in stop and go movements by suitable mechanism (not detailed) which is provided for use in connection with a product packaging operation. The tape advance mechanism 70 may be of any convenient design which may be adjusted to provide a suitable tape area for use by proportional sized indicia 60 as may be required. Thus, as best seen in FIG. 6 of the drawings the packing film 23 is advanced in the direction of the arrow 74, to provide a full measure of film for the packing operation and is effective to spot imprint areas 76, 77 at positions in register with the marker heads 34. In the FIG. 6, embodiment the packaging film 23 comprises a length of film with a series of side-by-side packaging areas 78, 79 extending therealong. Herein, an individual width portion 80 of the transfer type 22 is provided for use by the marker head 34a and a width portion 81 is provided for use by the market head 34b. 
     To provide these individual width portions 80 and 81, it will be seen that the path of tape movement is angled relative to the marker heads 34a and 34b by adjusting the position of the transfer tape assembly 64. The transfer tape frame 66 is pivotally carried by the elongated frame 28 on a shoulder bolt 82 or the like for adjustable movement about an axis 84. A pair of curved guide slots 86 are provided in the frame 66 with clamping screws 88 extending therethrough and threaded into the elongated frame 28 to provide means of locking the transfer tape assembly 64 and accordingly the transfer tape at a desired angle. 
     The adjusted angle of the tape 22 is determined primarily by the spacing between marker heads 34a and 34b. Thus, when the marker heads are moved apart to be placed in register with imprint areas 76a and 77a of a wide packaging film 23a as shown in FIG. 7, the tape angle β is adjustably decreased from the greater tape angle α required in the FIG. 6 embodiment to provide the full width portions 80 and 81. Further, it will be evident from the embodiments shown diagrammatically in FIGS. 8, 9 and 10 that an increase in the number or size of marker heads utilized in a packaging operation will necessitate the use of a wider transfer tape and require adjustment of the tape advancing means 70 to deliver a compatible tape area for use by the marker heads to provide suitable individual width portions, while changing the spacing between marker heads requires only that the tape angle be adjusted. 
     When imprints are to be applied to the film at close spacing, for example, as shown in FIG. 10, and the imprint areas on packaging film 23b are comparatively large, a pair of indicia areas 60a may be provided with each of the marking heads 34 in a somewhat offset aligned relationship to minimize the tape angle. 
     Further, in certain packing operations in which the imprint areas provided on packaging film 23c are comparatively large and arranged in end-to-end relationship as well as being side-by-side, two pairs of indicia areas 60b are provided on a single marker head 34 to imprint four adjacent packaging areas 90 simultaneously with additional pairs of indicia areas 60c carried by adjoining marker heads 34. The additional pairs of indicias 60c are shown in FIG. 11 as spaced apart longitudinally and arranged to imprint four more adjacent packaging areas 91 with any more required indicias spaced still further apart on their marker heads 34. In this embodiment, the path of the tape 22 is adjusted to a parallel, laterally aligned orientation relative to the marker heads with the offset spacing between the indicia on adjacent marker heads providing individual width portions of transfer tape for each indicia. Accordingly, the width portions or bands 92 are used by the indicia 60b; bands 93 are used by indicia 60c and bands 94 are provided when indicia 60d is required. Obviously, in this embodiment, the tape angle relative to the aligned marker heads 34 is set at 0°. 
     Thus, it will be recognized that the relationship of the tape angle relative to the aligned marker heads 34 enables the multiple imprint marking device 20 to be used in a wide range of applications and having a high degree of flexibility in operation.