Abstract:
The present invention is directed to a labeling apparatus designed to dispense and apply self-adhesive labels arranged on a carrier web, a base plate suitable therefor and a label web. A feed wheel for the carrier web is rotatably mounted on the base plate and has at both its end faces a ring of axial pins engageable by an operating lever pivotally mounted on a casing of the labeling apparatus in order to drive the feed wheel in increments. The feed wheel has a generating surface with two rings of radial projections in the form of knobs adapted to make positive engagement with recesses or cutouts of the carrier web. Instead of using knobs as projections, it is also possible to provide sprockets on the feed wheel which are adapted to make positive engagement with slits in the carrier web. The base plate is configured as an interchangeable base plate which is selectable in dependence upon the phase relationship of the rings of projections to the rings of axial pins of the feed wheel.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This utility application claims the benefit under 35 U.S.C. §119(e) of Provisional Application Ser. No. 61/147,652 filed on Jan. 27, 2009 entitled LABELING APPARATUS HAVING A PIVOTABLE BASE PLATE WITH FEED WHEEL and whose entire disclosure is incorporated by reference herein. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of Invention 
         [0003]    This invention relates to a labeling apparatus designed to dispense and apply self-adhesive labels arranged on a carrier web in which a feed wheel for the carrier web is rotatably mounted on a base plate and drivable in increments by an operating lever pivotally mounted on a casing of the labeling apparatus, in which the feed wheel has a generating surface with at least one ring of radial projections for positive engagement with the carrier web and has at both its end faces a ring of axial pins engageable by a feed pawl pivotal by the operating lever, and in which the base plate is configured to be swung away from the casing. 
         [0004]    Further, the invention relates to a base plate of the afore-mentioned labeling apparatus. Still further, the invention relates to a label web for a labeling apparatus with such a base plate. 
         [0005]    2. Description of Related Art 
         [0006]    A labeling apparatus of the kind referred to above is known from the document EP 0 039 803 A1. A labeling apparatus with a label web of the kind referred to above is known from the document DE 103 58 318 A1. The label web comprises a carrier web on which self-adhesive labels are carried. 
         [0007]    The labeling apparatuses disclosed in the two above-mentioned documents include a tongs-type, hand-operated device in which the labels with their carrier web are unwound from a label supply spool by a feed mechanism, advanced through a print mechanism and then fed to a dispensing lip where the labels are delaminated from the carrier web one by one and paid out. The feed mechanism and the print mechanism for printing on the label are driven by a pivotally mounted operating lever. This operating lever is arranged opposite a handle rigidly mounted on the casing. Using a swinging-in motion of the operating lever against the force of a spring, the print mechanism is moved against a platen for printing on a label resting on the platen. 
         [0008]    In the labeling apparatus disclosed in DE 103 58 318 A1, when the operating lever is swung back by spring force, the carrier web is held clamped between a clamping member of a feed pawl and a table of a transport slide and advanced by the transport slide by one label pitch. After the printed label has delaminated itself from the carrier web at the dispensing lip, it is applied to an object to be labeled by means of an applicator roll. 
         [0009]    In the labeling apparatus disclosed in EP 0 039 803 A1, a feed wheel used in lieu of the transport slide is mounted for rotation on a base plate and includes a generating surface with a ring of radial projections constructed as sprockets and engaging in prefabricated slits of the carrier web for advancing the label web after the labels preceding these slits are applied to an object to be labeled. 
         [0010]    For control of the labeling apparatus disclosed in DE 103 58 318 A1 which ensures that each label reaches the print mechanism and the dispensing lip in its proper position, the longitudinal edges of the carrier web which exhibit a special contour are traced. The proper position of the label web in the print mechanism is then ensured by the transport slide. By contrast, in the labeling apparatus disclosed in EP 0 039 803 A1, the proper position is ensured by the feed wheel whose sprockets engage the slits of the carrier web. 
         [0011]    A labeling apparatus of the type known from EP 0 039 803 A1 is only able to handle slitted webs of label material. While a labeling apparatus of the type known from DE 103 58 318 A1 is designed to handle label webs whose longitudinal edges exhibit a particular contour, these label webs may be additionally provided with slits to enable them to be used with a labeling apparatus of the aforementioned type which includes a feed wheel with sprockets. In the long run, a feed mechanism using a feed wheel basically operates more reliably than a feed mechanism using a transport slide since the latter&#39; s function may be impaired by paper shreds. On the other hand, the slits required for engagement of the sprockets of the feed wheel may impair the appearance of the label. A particular problem is the fixed length of feed in both known types of labeling apparatus, which is the reason why only labels of a specified length can be processed. In addition, this also prevents the possibility for the dispensing position to be adjusted or corrected, for example in order for the print mechanism to effect printing precisely in a preprinted zone of the label. Moreover, the feed mechanism with slide is only suitable for use with one particular type of label in which the label pitch is in a defined phase relationship to the pitch of the outer contour of the longitudinal edges of the carrier web. Accordingly, for any other label format and/or any other label length a different labeling apparatus is required in the prior art. 
         [0012]    To eliminate this problem, a labeling apparatus according to DE 38 43 113 A1 should therefore be able to accommodate different label lengths. In this labeling apparatus, an operating lever for driving a feed wheel provided with sprockets, rather than acting directly on a rack coupled to it by a pinion, is moved to swivel a two-armed swivel lever which in turn effects displacement of the rack. By interposing the swivel lever in the driving connection, a relatively large or relatively small displacement of the rack and thus a correspondingly large or small angle of rotation of the feed wheel should be produced. In this manner, the labeling apparatus should be suitable for applications involving labels of different lengths. However, this can be accomplished within limits only, because on a label web with feed slits the slits are prefabricated such as to be located at the parting line between two labels. On a label web including labels of a different length the slits between labels have to be spaced differently. If the slits were prefabricated anywhere within the label area, they would adversely affect the print image. Furthermore, interposition of the swivel lever allows neither adjustment nor correction of the dispensing position. 
         [0013]    All references cited herein are incorporated herein by reference in their entireties. 
       BRIEF SUMMARY OF THE INVENTION 
       [0014]    It is an object of the present invention to provide a labeling apparatus of the type initially referred to in such a way that different label webs which may include labels of different shape can be handled. Furthermore, it is desirable to provide a base plate suitable in particular for such a labeling apparatus and a suitable label web. 
         [0015]    According to the invention, this object is accomplished by 
         [0016]    a labeling apparatus characterized in that the radial projections are provided in two axially spaced rings on the generating surface of the feed wheel, said projections lying opposite each other in pairs and being adapted to make positive engagement with recesses or cutouts of the carrier web, and that the base plate is configured as an interchangeable base plate and is selectable in dependence upon the phase relationship of the rings of projections to the rings of pins of the feed wheel; 
         [0017]    a base plate; and 
         [0018]    a label web characterized in that the phase relationship of the pitch of the carrier web to the pitch of the strip of individual labels arranged on the carrier web is chosen such that each pair of recesses of the carrier web lies in the center between two straight and parallel boundary lines of each label which extend in a direction transverse to the longitudinal direction of the carrier web. 
         [0019]    The labeling apparatus according to the present invention retains the principle known from EP 0 039 803 A1 according to which the base plate is configured to be able to swing away from the casing for ease of access to all the parts mounted on the base plate if and when required. According to the present invention, the radial projections for advancing the carrier web are arranged and configured such as to make positive engagement with recesses or cutouts of the carrier web. Furthermore, according to the present invention the base plate is configured to be an interchangeable base plate which can be readily replaced with an interchangeable base plate mounting a different feed wheel when required. In the base plate of the labeling apparatus according to the present invention the position of the labels relative to the recesses or cutouts of the label web may vary. Allowance for this can be made simply by selecting a feed wheel on which the rings of projections are arranged in a defined phase relationship to the rings of pins through which the feed wheel is driven. Considering that only the feed wheel changes from one interchangeable base plate to the next, it would also be conceivable to replace only the feed wheel while retaining the interchangeable base plate. Conveniently, however, the base plate according to the present invention is configured to be a disposable item which, when required, is simply replaced with a base plate having a similar or a dissimilar feed wheel. In either case, the base plate of the labeling apparatus according to the present invention also enables label webs to be handled which have a wavy or serrated outer contour along their longitudinal edges and/or cutouts in the form of slits. The shape of the label can be selected, for example, by placing it with its center axis onto the center axis between two recesses or two elevations of the carrier web or to any position in-between. Allowance for the one or the other case is made by using a base plate according to the present invention with a corresponding feed wheel on which the ring of pins for driving the feed wheel is in a defined phase relationship to the ring of projections. In the period around 1970/71, applicant manufactured a handheld labeler (Meto 105 type) which included a feed wheel with rings of knobs at the axial ends of its generating surface, but this one was fixedly installed in the interior of the handheld labeler and therefore not accessible. 
         [0020]    The label web according to the present invention for a labeling apparatus with a base plate according to the present invention enables the label shape to be varied in a convenient way by selecting the phase relationship of the pitch of the carrier web to the pitch of the strip of individual labels arranged on the carrier web to be correspondingly selected, for example by arranging each pair of elevations or recesses of the carrier web, instead of in the center, in displaced relation to the center between two straight and parallel boundary lines of each label which extend face in a direction transverse to the longitudinal direction of the carrier web. 
         [0021]    In one aspect of the present invention a return stop is used for the feed wheel, which return stop comprises cams formed on the feed wheel and a detent spring protruding from the base plate and engageable with the cams. Each feed wheel, related to the associated label shape, can be easily adapted to the return stop by selecting the phase angle of the cams of the return stop in conformity with the phase angle of the pins provided for driving the cam wheel. In this arrangement, the detent spring can be a spring arm formed on the base plate, which enables it to be manufactured with the base plate in simple manner. 
         [0022]    In another aspect of the present invention the feed wheel has in its generating surface a central annular recess in which the cams are formed at the bottom. Therefore, its proper relation to the return stop can be re-established easily when a feed wheel is replaced. 
         [0023]    In a further aspect of the present invention the inner side of the base plate includes at least one deflector for the carrier web, which deflector is configured to extend obliquely upwardly into the central annular recess of the feed wheel so that guidance of the carrier web can be ensured in simple manner on its leaving the feed wheel and the base plate. 
         [0024]    In a further aspect of the present invention the base plate includes two axle stubs integrally formed at its one end face, which stubs are snap-fittable into associated bores in mutually opposite sidewalls of the casing and are rotatable in said bores for swinging the base plate away so that the base plate is easily releasable from the casing for replacement by temporarily urging the sidewalls slightly apart in the area of the axle stubs, or by temporarily pressing the end faces of the base plate carrying the axle stubs slightly together. 
         [0025]    In a further aspect of the present invention the feed wheel includes axle stubs at its end faces which are snap-fitted into associated bores in mutually opposite sidewalls of the base plate so that the feed wheel can be mounted or demounted easily by temporarily urging the sidewalls of the base plate slightly apart. 
         [0026]    In a further aspect of the present invention the base plate pivotally mounts a web guide which covers the feed wheel in a semicircle and can be swung away from the feed wheel so that it is ensured that the carrier web wraps around the feed wheel closely on its advancing movement, while yet the feed wheel can be replaced easily by swinging the web guide away. 
         [0027]    In a further aspect of the present invention the web guide includes two integrally formed axle stubs snap-fitted into associated bores in the sidewalls of the base plate so that the web guide can be mounted on the base plate with ease. 
         [0028]    In a further aspect of the present invention two flexible arms are provided at the end face of the web guide opposite its pivot bearing, each arm including a pin adapted to snap into associated bores in the sidewalls of the base plate so that the web guide can be releasably locked in its operating position in a simple manner. In addition, a platen of a print mechanism received in the casing for printing on the labels can be arranged on the base plate, which enables the platen to be readily exchanged together with the base plate. 
         [0029]    In a further aspect of the present invention two shallow grooves for receiving friction rings are provided on the feed wheel in its generating surface adjacent to its end faces so that entrainment of the carrier web by the knobs on the feed wheel can be enhanced additionally by the mutual friction between carrier web and friction rings. 
         [0030]    In a further aspect of the present invention the base plate includes in the area of the generating surface of the feed wheel a wall portion recessed cylindrically towards the outside so that the overall height of the base plate can be kept low. 
         [0031]    In a further aspect of the present invention the detent spring is a raised and reinforced section of the recessed wall portion of the base plate, which section extend faces into the central annular recess of the feed wheel so that the detent spring can be manufactured easily in conjunction with the base plate. 
         [0032]    In a further aspect of the present invention the radial projections are configured as rings of knobs at the axial ends of the generating surface so that a particularly reliable positive-engagement relationship between carrier web and feed wheel is ensured. 
         [0033]    In a further aspect of the present invention axially opposite knobs have edges facing each other in a convex configuration, each with a contour corresponding to the arc of a circle having a radius of curvature shaped to conform to a corresponding radius of curvature of a wave-shaped longitudinal edge of the carrier web or an arc of an envelope circle of each recess in the longitudinal edge of the carrier web so that it is possible for one and the same feed wheel to handle carrier webs with variously shaped elevations and recesses. 
         [0034]    In a further aspect of the present invention on axially neighboring knobs the circular arc merges into a knob flank at the location where the relative axial distance of two axially neighboring knobs is at a minimum, which knob flank is parallel to the axis of the feed wheel so that the knobs are adapted to make positive engagement with the outer edge of the carrier web, but only on that part of the edge that precedes them in the feed direction. This facilitates the process of threading the carrier web into the rings of knobs. 
         [0035]    In a further aspect of the present invention the radial projections are constructed as rings of sprockets so that the labeling apparatus is able to handle carrier webs having cutouts in the form of slits for positive engagement with the sprockets. 
         [0036]    In a further aspect of the present invention a slide is provided which is arranged in an opening in the base plate and adjustable in a direction transverse to the axis of the feed wheel, and the slide&#39;s outer surface which covers the opening is configured to be a guide surface for the carrier web so that it is possible, by adjusting the position of the slide, to adjust the length of travel of the carrier web between the position at which the labels are dispensed and the first pair of knobs with which the carrier web makes engagement. In this manner, it is possible for example, to match the position in which printing on the label is effected accurately to a preprinted image on a label by suitably adjusting the dispensing position. For this purpose, adjustment of the slide will cause its outer surface to protrude from the outer side of the base plate to a greater or lesser extent. 
         [0037]    In a further aspect of the present invention the base plate mounts a guide roller for the carrier web, which roller is rotary about an axis parallel to the axis of the feed wheel so that the carrier web can be reliably directed onto the feed wheel on its advancing motion. 
         [0038]    In a further aspect of the present invention the guide roller includes two integrally formed axle stubs snap-fitted into associated bores in sidewalls of the base plate so that the guide roller can be mounted and demounted just as easily as the feed wheel. 
         [0039]    In one aspect of the label web according to the present invention the pitch of the longitudinal edges of the carrier web equals the label length so that the outer contour of the labels can be varied as desired with particular ease. 
         [0040]    In another aspect of the label web according to the present invention the elevations and recesses of the lines of the longitudinal edges of the label web are of a sinusoidal, rectangular, trapezoidal or V-shaped configuration so that a wide range of options regarding the label shape is provided. 
     
    
     
       BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS 
         [0041]    The invention will be described in conjunction with the following drawings in which like reference numerals designate like elements and wherein: 
           [0042]      FIG. 1  is an elevational view of a labeling apparatus according to the present invention comprising a first preferred embodiment of a base plate; 
           [0043]      FIG. 2  is a view of the labeling apparatus of  FIG. 1  showing additionally in a broken away representation the base plate in longitudinal section; 
           [0044]      FIG. 3  is a view of the labeling apparatus of  FIG. 1 , showing the base plate swung away from the casing; 
           [0045]      FIG. 4  is an exploded perspective view of those parts of the labeling apparatus that effect the drive of a feed pawl for a feed wheel rotatably mounted on the base plate; 
           [0046]      FIG. 5  is a perspective view of the complete base plate; 
           [0047]      FIG. 6  is a view of the base plate of  FIG. 5 , showing a web guide in swung open condition; 
           [0048]      FIG. 7  is a perspective view of the base plate of  FIGS. 5 and 6 , absent all the moving parts thereof; 
           [0049]      FIG. 8  is a plan view of the base plate of  FIG. 5 ; 
           [0050]      FIG. 9  is a longitudinal sectional view of the base plate taken along the line IX-IX of  FIG. 8 ; 
           [0051]      FIG. 10  is a perspective view of a slide representing a detail of the base plate of  FIG. 9 ; 
           [0052]      FIG. 11  shows in  FIG. 11   a  first preferred embodiment of the feed wheel in an elevational view, in  FIG. 11   b  the feed wheel in a sectional view taken along the line B-B of  FIG. 11   a , in  FIG. 11   c  the feed wheel in an end view, in  FIG. 11   d  the feed wheel in a longitudinal sectional view taken along the line D-D of  FIG. 11   c , in  FIG. 11   e  as a detail E of  FIG. 11   a  one of a plurality of knobs of the feed wheel, and in  FIG. 11   f  the feed wheel in a perspective representation; 
           [0053]      FIG. 12  shows in  FIGS. 12   a - 12   d , in like views as in  FIGS. 11   a - 11   d , a second preferred embodiment of the feed wheel comprising sprockets in lieu of knobs; 
           [0054]      FIG. 13  is a perspective view of a guide roller; and 
           [0055]      FIGS. 14 to 21  are views of variously shaped labels adapted to be handled with a labeling apparatus according to the present invention which includes a feed wheel with knobs, showing at a) three label webs arranged side-by-side as they are being manufactured and at b) one label as an individual representation. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0056]    The labeling apparatus according to the present invention illustrated in  FIGS. 1-3  and generally designated as  10  is similar in construction to a labeling apparatus according to the document DE 103 58 318 A1 initially cited, except for the construction of a base plate  50  carrying a feed mechanism, generally designated as  40 , for a carrier web  15 , and except for a feed pawl  60  which is pivotable through intermediate members by an operating lever  20  of the labeling apparatus  10 . Therefore, with the exception of the base plate  50  with its feed mechanism  40 , the labeling apparatus  10  will be described with reference to  FIGS. 1-4  only to the extent necessary for an understanding of the present invention. The remaining figures will be described subsequently, illustrating the base plate  50  with the feed mechanism  40  arranged on it and a label web in detail. 
         [0057]    The labeling apparatus  10  illustrated in  FIGS. 1-3  includes a casing  11  formed of two plastic shells fitted together and having a handle  12  formed thereon. On the casing upper side is a bay  13  for receiving a supply roll  14  ( FIG. 2 ) of a carrier web  15  ( FIG. 14   a ) to which self-adhesive labels  16  ( FIG. 14   b ) are adhered. The carrier web  15  is routed in the labeling apparatus  10  from the supply roll  14  in the bay  13  to the bottom right in the representation of  FIG. 2  to a dispensing lip  18  where the carrier web  15  is turned around to be routed through the feed mechanism  40  to the rear end face of the casing  11 . Opposite the dispensing lip  18 , an applicator roll  17  is rotatably mounted in the casing  11  in order to enable a label delaminated from the carrier web  15  at the dispensing lip  18  and occupying a dispensing position to be adhered to an object by a rolling motion of the applicator roll  17 . 
         [0058]    Beneath the handle  12  the labeling apparatus  10  includes an operating lever  20  mounted on the casing  11  for pivotal motion about an axis  23 . According to the representation of  FIG. 4 , a spring  24  is seated between the operating lever  20  and a print mechanism lever  25  to urge the operating lever  20  into a rest position as shown in  FIG. 3 . The print mechanism lever  25  is likewise mounted for pivotal motion about the axis  23 . The print mechanism lever  25  supports a print mechanism  26  to enable a self-adhesive label  16  resting on a platen  27  to be printed. Seated between the operating lever  20  and the print mechanism lever  25  is a spring  29  ( FIG. 4 ) serving to transmit a movement of the operating lever  20  against the handle  12  to the print mechanism lever  25 . In the rest position shown in  FIG. 3 , the print mechanism lever  25  is held in a raised position by the operating lever  20 . 
         [0059]    In contrast to the labeling apparatus known from DE 103 58 318 A1 which provides a transport slide slidably mounted in the casing  11 , the feed mechanism  40  includes a feed wheel  70  rotatably mounted on the base plate  50 , which feed wheel uses knobs  74  to make positive engagement with the carrier web  15  for advancing it, as will be described in more detail further below in conjunction with the base plate  50 . Moreover, unlike the labeling apparatus known from DE 103 58 318 A1, the dispensing lip  18 , instead of being a front part of the casing  11 , is formed by the front edge of the base plate  50 . 
         [0060]    For a brief description of an operating cycle of the labeling apparatus  10  illustrated in  FIGS. 1-4 , it is assumed that no self-adhesive label as yet occupies the dispensing position underneath the applicator roll  17 . To initiate an operating cycle, the operating lever  20  is pulled towards the handle  12  as a result of which the print mechanism lever  25 , owing of the effect of an arm  28  and the spring  29 , is pivoted counterclockwise about the axis  23 , thereby causing the print mechanism  26  to be lowered onto the platen  27  on the base plate  50 . On impact with the platen  27 , the print mechanism  26  produces a print on the self-adhesive label  16  resting on the platen  27  at this particular instant. Via a lever  30  also pivotably mounted on the casing  11  but driven by the print mechanism lever  25 , on each actuation of the operating lever  20  the feed wheel  70  is rotated through one increment by means of a feed pawl  60 , thereby causing the carrier web  15  to be moved towards the platen  27 . When the operating lever  20  is released, the spring  24  returns the operating lever  20  to the initial position shown in  FIG. 3 , in which process the operating lever  20  pivots the print mechanism lever  25  clockwise about the axis  23 . At the same time, the feed pawl  60  is moved back into engagement with the feed wheel  70 , as will be also explained in greater detail further below. As this occurs, the label web is pulled around the dispensing lip  18 , whereby one self-adhesive label  16  delaminates itself from the carrier web  15  at the dispensing lip  18  and reaches the position underneath the applicator roll  17 . The self-adhesive label  16  is now ready for being adhered to an object by the rolling motion of the applicator roll  17 . Springs  31  ( FIG. 4 ) urge the lever  30  into its initial position. The feed pawl  60  is pivoted to the lever  30  on an axis  32 . A more detailed description of the base plate  50  and the feed wheel  70  will be given in the following. 
         [0061]      FIG. 11   a  shows a first preferred embodiment of the feed wheel  70  in an elevational view. The feed wheel  70  has in its generating surface  72  a central annular recess  76 . Formed in the recess  76  is a ring of cams  78  as becomes apparent from  FIG. 11   b  showing a section taken along the line B-B of  FIG. 11   a . The cams  78  are part of a return stop for the feed wheel  70 , which return stop comprises, in addition to the cams  78  provided on the feed wheel  70 , a detent spring  80  protruding from the base plate  50  and resiliently engageable with the cams, as best shown in  FIGS. 7 to 9 .  FIG. 2  shows the cooperative relationship between the detent spring  80  and the cams  78 . The representation of  FIG. 2  shows that the feed wheel  70  is rotatable counterclockwise, with the detent spring  80  being resiliently disengaged by each cam  78  until it engages the feed wheel  70  again behind a cam  78 , thereby preventing the feed wheel  70  from rotating clockwise and hence the carrier web  15  from being fed back. The detent spring  80  is a spring arm formed on the base plate  50 . 
         [0062]    Furthermore, according to the representation of  FIG. 11  the feed wheel  70  includes at its end faces axle stubs  81 ,  82  of different diameter which are snap-fitted into associated bores  83 ,  84  ( FIG. 7 ) in mutually opposite sidewalls  85 ,  86  of the base plate  50 , as becomes apparent from  FIGS. 5 and 6 . In addition, the feed wheel  70  includes in its generating surface  72  adjacent to its end faces two shallow grooves  73 ,  75  for receiving friction rings  77  indicated in section only in  FIG. 11   d  which is a longitudinal sectional view of the feed wheel  70  taken along the line D-D of  FIG. 11   c . At its two axial end faces the feed wheel  70  has a respective ring of axial pins  87  and  88  which are engageable by the feed pawl  60  pivotable by the operating lever  20  in order to rotate the feed wheel  70  through one increment on each actuation of the operating lever  20 . 
         [0063]    The knobs  74  are axially opposed to each other and have mutually facing edges shaped in a convex configuration, each with the contour of a circular arc of a curvature radius R (indicated in  FIG. 11   e  as detail E of  FIG. 11   a ) which is shaped to conform with a corresponding curvature radius of a wave-shaped outer edge of the carrier web  15  ( FIG. 13   a ) or an arc H of an envelope circle of each recess in the carrier web  15  ( FIG. 15   a ). 
         [0064]    On axially neighboring knobs  74  the circular arc merges into a knob flank  74   a  at the location where the relative axial distance of two neighboring knobs is at a minimum, which knob flank is parallel to the axis  71  of the feed wheel  70 , as best seen in  FIG. 11   e.    
         [0065]    The base plate  50  is configured as an interchangeable base plate which is selectable in dependence upon the phase relationship between the rings of knobs  74  and the rings of pins  87 ,  88  on the feed wheel  70 . The structure of the base plate  50  will now be further described with reference to  FIGS. 5-13 . The base plate  50  includes at one end face two integrally formed axle stubs  89  which are adapted to be snap-fitted into associated casing bores in the two mutually opposite sidewalls  85 ,  86  of the casing  11  and are rotatable in said casing bores for swinging the base plate  50  open.  FIG. 3  shows the base plate in swung-open condition. The base plate  50  mounts a guide roller  92  ( FIG. 13 ) for the carrier web  15 , which guide roller is rotary about an axis parallel to the axis of the feed wheel  70 . The guide roller  92  includes two integrally formed axle stubs  93 ,  94  which are snap-fitted into associated bores  95  and  96 , respectively, in the sidewalls  85 ,  86  of the base plate  50  ( FIG. 7 ). Furthermore, the base plate  50  pivotally mounts a web guide  97  which covers the feed wheel  70  in a semicircle and is adapted to be swung away from the feed wheel  70 , as shown in  FIGS. 5 and 6 . 
         [0066]    The web guide  97  includes two integrally formed axle stubs  98  snap-fitted into associated bores  99  in the sidewalls  85 ,  86  of the base plate  50  ( FIGS. 6 and 7 ). At the end face of the web guide  97  remote from its pivot bearing two flexible arms  100  are formed, each mounting a respective pin  101 . Each pin  101  is adapted to be snap-fitted into an associated bore  102  in the sidewalls  85 ,  86  of the base plate  50 . The base plate  50  further mounts the above-referenced platen  27  of the print mechanism  26  accommodated in the casing  11  for printing on the labels  16 . Furthermore, the inner side of the base plate  50  includes a deflector  103  configured to extend face obliquely upwardly into the central annular recess  76  of the feed wheel  70  ( FIGS. 6-8 ). The deflector  103  serves an additional guiding function for the carrier web  15 . In the area of the generating surface  72  of the feed wheel  70  the base plate  50  is provided with a wall portion  79  cylindrically recessed outwardly. The detent spring  80  is a raised and reinforced section of the recessed wall portion  79  of the base plate  50 , which raised section extend faces into the central annular recess  76  of the feed wheel  70 , as best seen in  FIG. 9 . The base plate  50  and all the parts mounted on it and described up to this point are injection-molded parts fabricated from a plastic. 
         [0067]    According to the representation of  FIGS. 8 and 9 , an opening  51  in the base plate  50  receives a slide shown in  FIG. 10  as a detail and generally designated as  52 , which is adjustable in a direction transverse to the axis  71  of the feed wheel  70  by means of a self-tapping screw  53 . The slide  52  is equally an injection-molded component provided with grooves  54 ,  55  on opposite sides for engagement with guide ribs  56 ,  57  integrally formed on the sidewalls  85 ,  86  of the base plate  50 . The screw  53  is movable with its head in the slide  52 , but held captive therein, as becomes apparent from  FIG. 9 . According to the representation of  FIG. 7 , the base plate  50  includes between its sidewalls  85 ,  86  an integrally formed partition wall  58  having in its center an integrally formed bushing  59  in which the self-tapping screw  53  is threadedly received. The outer surface  62  of the slide  53  covering the opening  51 , that is, its bottom surface as seen looking at  FIGS. 9 and 10 , provides a guide surface for the carrier web  15 . The route of the carrier web in the area of the base plate  50  is shown in  FIG. 2 . When the carrier web  15  travels past the dispensing lip  18 , paying out one of the labels  16 , it moves along the lower outside of the base plate  50  and the outer surface  62  of the slide  52  to enter a gap between the guide roller  92  and the feed wheel  70 . The latter entrains with its knobs  74  the carrier web  15  by positive engagement to ultimately deliver it to the outside through the deflector  103 . The length of travel of the carrier web  15  between the dispensing lip  18  and the first pair of knobs engaging is adjustable by adjusting the slide  52 . 
         [0068]      FIGS. 12   a - 12   d  show in like views as in  FIGS. 11   a - 11   d  a second embodiment of the feed wheel  70  which differs from the feed wheel  70  of  FIG. 11  only in that it comprises, in lieu of two rings of knobs  74 , two rings of sprockets  104  as radial projections. The two rings of sprockets  104  are arranged at the two mutually opposite edges of the recess  76  of the feed wheel  70  on its generating surface. The construction of the feed wheel  70  equipped with the sprockets  104  being otherwise identical to the construction of the feed wheel  70  provided with the knobs  74 , there is accordingly no need to discuss the construction of the feed wheel  70  of  FIG. 12  in greater detail. The sprockets  104  are adapted to make positive engagement with a carrier web which, in lieu of or in addition to the elevations and recesses on its longitudinal edges  162 , includes sated cutouts between its longitudinal edges into which the sprockets  104  can engage for a positive-engagement advancing motion of the carrier web. 
         [0069]    A label web for the labeling apparatus  10  with the base plate  50  and the feed wheel  70  provided with the knobs  74  will now be described in more detail with reference to  FIGS. 14-21 . The label web comprises the carrier web  15  and the self-adhesive labels  16  arranged on it. The two longitudinal edges  162  of the label web are configured to be continuous lines of opposite phase with like elevations and recesses alternating at regular intervals, with the elevations and recesses lying opposite each other in pairs across the width of the label web, as becomes readily apparent from  FIGS. 14-21 . The phase relationship of the pitch of the carrier web  15  to the pitch of the strip of individual labels  16  arranged on the carrier web is chosen in such a way that each pair of recesses of the carrier web lies in the center between two straight and parallel boundary lines of each label  16  extend facing in a direction transverse to the longitudinal direction of the carrier web  15 , as shown in  FIGS. 15 ,  17 ,  19  and  21  for label webs having variously shaped longitudinal edges, including elevations and recesses of the lines of the longitudinal edges which are of a sinusoidal ( FIGS. 14 and 15 ), rectangular ( FIGS. 16 and 17 ), V-shaped ( FIGS. 18 and 19 ) or trapezoidal ( FIGS. 20 and 21 ) configuration.  FIGS. 14 ,  16 ,  18  and  20  show label strips with known shapes of label, yet equally handleable by the labeling apparatus  10 , provided that the phase relationship of the pitch of the carrier web  15  to the pitch of the strip of individual labels arranged on the carrier web  15  is chosen such that each pair of elevations of the carrier web  15  lies in the center between two straight and parallel boundary lines of each label  16  which extend face in a direction transverse to the longitudinal direction of the carrier web  15 . In all cases, the pitch of the lines of the longitudinal edges  162  of the carrier web  15  is equal to the label length. 
       LIST OF REFERENCES  
       [0000]    
       
           10  labeling apparatus 
           11  casing 
           12  handle 
           13  bay 
           14  supply roll 
           15  carrier web 
           16  self-adhesive labels 
           16   a  boundary line 
           16   b  boundary line 
           17  applicator roll 
           18  dispensing lip 
           20  operating lever 
           23  axis 
           24  spring 
           25  print mechanism lever 
           26  print mechanism 
           27  platen 
           28  arm 
           29  spring 
           30  lever 
           31  spring 
           32  axis 
           40  feed mechanism 
           50  base plate 
           51  opening 
           52  slide 
           53  screw 
           54  groove 
           55  groove 
           56  guide rib 
           57  guide rib 
           58  transverse wall 
           59  bushing 
           60  feed pawl 
           62  outer surface 
           70  feed wheel 
           71  axis 
           72  generating surface 
           73  groove 
           74  knob 
           74   a  knob flank 
           75  groove 
           76  recess 
           77  friction rings 
           78  cam 
           79  wall portion 
           80  detent spring 
           81  axle stub 
           82  axle stub 
           83  bore 
           84  bore 
           85  sidewall 
           86  sidewall 
           87  pins 
           88  pins 
           89  axle stub 
           92  guide roller 
           93  axle stub 
           94  axle stub 
           95  bore 
           96  bore 
           97  web guide 
           98  axle stub 
           99  bores 
           100  arms 
           101  plug 
           102  bore 
           103  deflector 
           104  sprockets 
           161  recesses 
           162  longitudinal edges 
           163  deflector 
         H arc of envelope circle 
         R radius 
       
     
         [0144]    While the invention has been described in detail and with reference to specific examples thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.