Abstract:
The present invention relates to a conveyor that includes at least one dogging device. The dogging device includes a plurality of dogging yokes ( 105 ). These are arranged to move commonly after one another and in mutually spaced relationship in a transport direction. The conveyor is constructed to move booklets ( 1 ) piece-wise in the transport direction, by virtue of a pair of adjacent dogging yokes ( 105 ) being arranged to straddle a side edge of a booklet ( 1 ) with clearance in the transport direction. The object of the invention is to avoid an oblique or inclined orientation of the booklets between the dogging yokes. According to the invention, there is provided a support device ( 106 ) which acts between two adjacent dogging yokes ( 105 ) which at least partially bridge the clearance when one side edge of a booklet ( 1 ) is straddled by the adjacent dogging yokes ( 105 ). The invention also relates to a method for moving booklets, wherein one side edge of a booklet ( 1 ) is straddled by dogging yokes ( 105 ) with clearance in the transport direction. The clearance is reduced subsequent to straddling of a booklet.

Description:
FIELD OF INVENTION 
   The invention relates to a conveyor and to a method of conveying. The invention also relates to a booklet comprising a bundle of sheets, for instance paper sheets, and a casing or cover which encases a bundle. The term booklet also includes finished booklets, where the bundle of sheets is fastened to the casing, and also booklets where the bundle of sheets has not yet been secured to the casing. 
   DESCRIPTION OF THE BACKGROUND ART 
   There has long been known in the art a method of manufacturing booklets that comprise a bundle of sheets, for instance paper sheets, and a casing includes providing the casing with a spine and applying to the inner surface thereof a binding agent in the form of a deactivated glue. The bundle of sheets is inserted into the casing such as to bring one side edge of the bundle into abutment with the glue on the casing spine. The casing is normally comprised of cover sheets that form a front side and a back side which are connected to the spine, said front and back covers having essentially the same shape and size as the sheets in said bundle. The casing may also be made of paper, although it can, of course, be made of any other suitable material. 
   When the bundle is in place in the casing, the glue on the spine of the casing is activated so as to firmly glue the bundle to the spine, along one of the side edges of said bundle. This can be achieved, for instance, by initially applying the glue in a solid state and then heating the glue so as to bring it to a liquid or semisolid state. In this regard, one side edge of each sheet in the bundle is in contact with the glue. The glue is then allowed to cool to a solid state, therewith fastening the bundle of sheets to the spine of the casing. 
   When a large number of booklets are to be produced, it is known to automate the whole of the manufacturing process or parts thereof. Thus, apparatus are known by means of which manufacture can be automated. It is known to use in such arrangements or plants conveyors that transport a casing to a gluing station from a compilation station in which a sheet bundle is inserted into said casing. In this known arrangement, the gluing station includes a conveyor by means of which a plurality of booklets are moved singly and sequentially in a transportation direction that is generally perpendicular to the plane of each booklet. The booklets are therewith moved over a glue-activating unit, where the spine of each booklet is moved in the close proximity of a heating element, so as to melt the glue. In the case of this known arrangement in which the sheet bundle rests with one of its side edges against the spine of the casing, the side edges penetrate slightly into the glue as a result of the gravitational force acting on the bundle. Each booklet is then allowed to cool, so as to unite said bundle with the casing and therewith obtain a finished booklet. 
   The known conveyor includes two dogging devices, each having a plurality of dogging yokes. The conveyor-carried dogging yokes are moved along the glue-activating unit in the transporting direction. Each booklet arriving at the glue-activating unit is positioned with a pair of dogging yokes on each dogging device straddling two mutually opposing side edges of the booklet. In order to enable the booklet to be inserted between the two pairs of dogging yokes, the latter are spaced apart at a distance which is greater than the thickness of the booklet, so that straddling can take place with a relatively large clearance in the transport direction. Because the arrangement shall be able to deal with booklets of mutually different thicknesses, the distance between mutually adjacent dogging yokes is adapted so that the clearance provided will be sufficient to accommodate booklets of relatively large thickness. The clearance can therefore be relatively large in respect of the manufacture of thinner booklets. This is necessary in order to be able to place a booklet readily and securely in conveyors, particularly when it is automated as in the case of the known arrangement. A booklet manufacturing apparatus of this kind is described in WO91/04159, for instance. 
   SUMMARY OF THE INVENTION 
   Although an arrangement of this earlier known kind has been found effective in the manufacture of booklets, it has been found that said necessary clearance has a number of drawbacks from certain aspects. This particularly applies when the booklets to be manufactured are relatively thin. In the case of dogging yokes that are spaced apart at a distance of 20 mm, the distance between two mutually adjacent dogging yokes will be about 16 mm when taking into account the inherent thickness of respective dogging yokes. This clearance will be rather high in the case of booklets whose thickness is less than 12 mm. Consequently, when the booklet has been placed with two mutually opposing side edges between a pair of dogging yokes on each dogging device, the booklet will tend to slope towards the front or rear dogging yoke in each pair. The booklet will therefore be curved in an arc between the dogging yokes. In conjunction with activating the glue, it is normally necessary to jog the sheets in the bundle initially from above, so as to ensure that all sheets will be properly glued. This jogging is made difficult by the fact that the booklet is arched between the dogging yokes, since the booklet will spring when jogged. This can make it difficult to fasten the outermost sheets in the bundle properly in the glue. It will also result in the formation of an angle between the bundle and the spine of the casing when the glue has solidified. 
   Against this background, the object of the present invention is to provide a conveyor in which booklets can be transported without risk of becoming slanted. 
   According to a first aspect of the invention, this object is achieved with a conveyor of the kind defined in the preamble of claim  1  and having the particular features set forth in the characterising clause of said claim. Because support elements are arranged in the space between two dogging yokes, it is ensured that the booklet will be straightened as it is straddled and be generally straight in a plane perpendicular to the movement direction. 
   Because the support element is resilient (springy) an appropriately chosen pressing force from the support element can be obtained in a simple fashion. Moreover, the conveyor can be adapted to handle booklets of mutually different thicknesses in a purposeful manner. 
   Moreover, because the resilient element is adapted to be supported against one of the two dogging yokes, there is obtained a simple and purposeful arrangement for achieving said resilience or spring action. In this respect, the support element is conveniently affixed to the dogging yoke, which constitutes a preferred, further embodiment. 
   The side edges of a booklet are straddled by the dogging yokes. It will be noted, however, that in some cases, when the booklets are thin, a number of booklets may be straddled by a pair of dogging yokes at one and the same time. The term booklet as used in the claims shall therefore be interpreted as also including a bunch of several booklets. 
   Although the invention finds its origin in providing a solution to a problem that occurs at a specific tempo in the booklet manufacturing process, its application is not restricted to this problem. An inventive conveyor thus includes applications other than the application concerned with booklets moving over a glue-activating device. 
   According to another preferred embodiment of the invention, an activator is provided for activating the support element subsequent to said mutually adjacent dogging yokes having straddled one side edge of a booklet. Because the support element is arranged not to be activated until this stage is reached, it will not hinder positioning of the booklet between the dogging yokes. 
   According to a further preferred embodiment of the invention, the activating device for activating a respective support element is arranged to activate said element when it is located in a predetermined position in the direction of transportation. This provides a practical manner of automatically bringing the support element to an active state. 
   According to a further preferred embodiment, each support element is adapted to act along essentially the whole of respective side edges. This increases the certainty of correct orientation of the booklets, i.e. in positioning the booklets flat in a plane perpendicular to the direction of transportation. 
   In a further preferred embodiment, the support element has the form of an elongate, generally flat strip that includes one or more tongues which project out from the plane of the strip and which form the resilient or springy elements and which are angled to the plane of the strip in the absence of load. Because the angled tongues are supported resiliently, or springingly, against the dogging yoke, there is obtained a very simple way of spring-loading the support element. 
   According to a preferred embodiment, each tongue is made in a piece integral with the strip and of the same material as said strip. The spring-loaded support element can therewith be produced very easily and inexpensively. 
   According to a further preferred embodiment, the tongues can be bent in towards the plane of the strip, wherewith, when the support element is deactivated, the tongues will be situated essentially in the plane of the strip. The spring element will therewith require the minimum of space. 
   According to a further preferred embodiment, the support element is affixed to the adjacent dogging yoke with the aid of hinge means. The support element can therewith readily be activated and caused to lie in abutment with the booklet. 
   According to a further preferred embodiment, the support element, when in a deactivated state, is adapted to lie tightly adjacent and parallel with the adjacent dogging yoke, and, in an activated state, to define an angle with said dogging yoke, wherewith the resilient element is adapted to exert a force that increases said angle. This results in an arrangement in which simplicity, reliability and a small space requirement for functioning of the support element are united in an optimal fashion. An effective clamping effect is obtained between the support element and the dogging yoke situated on the opposite side of the booklet. 
   According to a further preferred embodiment of the inventive conveyor, said conveyor includes two dogging devices. Each dogging device acts on a respective opposite side edge of the booklet. Movement of the booklet in this way, with a dogging yoke at each end edge results in safer and more stable transportation. 
   The other dogging device will also suitably include support elements of one of the preferred kinds, so as to ensure that the booklets will be properly aligned, in an optimal fashion. 
   The second or other dogging device will conveniently be identical to the first dogging device, therewith increasing safety and keeping down manufacturing costs. 
   According to a further preferred embodiment, the conveyor is adapted to move booklets that consist of a sheet bundle and a casing, said sheet bundle not being affixed to the casing prior to transportation, wherein, during transportation, a glue-activating device, preferably a heating device, functions to activate a glue applied to the casing, so as to affix the sheet bundle to the casing. Although an inventive conveyor can be used purposefully in various connections when booklets shall be transported, it is primarily with an application according to this embodiment that the advantages afforded by the conveyor become especially valuable, since it is here of great significance to the end result that the booklets are not curved or angled as they are transported. 
   The advantages afforded by a conveyor that also includes a sheet jogging device are also especially valuable. This is because jogging is facilitated when the booklets are flat, as they do not spring when in this state. Consequently, this constitutes a further preferred embodiment of the inventive conveyor. 
   The aforesaid advantageous embodiments of the inventive conveyor will be apparent. 
   By firmly clamping each booklet between a pair of dogging yokes in accordance with the method, the document is orientated in a manner corresponding to that described above with respect to the inventive conveyor. 
   Advantageous embodiments of the inventive method will be apparent. The advantages gained by these advantageous embodiments of the inventive method correspond to those advantages described above with respect to advantageous embodiments of the inventive conveyor. 
   The invention will now be described in more detail with reference to preferred embodiments thereof and also with reference to the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a partially cut-away perspective view of a casing with an inserted, but not yet affixed, sheet bundle. 
       FIG. 2  is a section view taken on the line II—II in FIG.  1 . 
       FIG. 3  is a partially cut-away perspective view of a machine for binding sheet bundles in casings of the type of booklet shown in  FIGS. 1 and 2 . 
       FIG. 4  is a side view of the machine in  FIG. 3 , as seen from the right. 
       FIG. 5  is a schematic perspective view of a sheet jogging device included in the machine according to FIG.  3  and  FIG. 4 , among other things. 
       FIG. 6  is an elemental illustration of the position of the booklets in a conventional conveyor, seen in side view. 
       FIG. 7  is an illustration of an inventive conveyor, corresponding to FIG.  6 . 
       FIG. 8  illustrates the conveyor of  FIG. 7  from above. 
       FIG. 9  is a perspective view of part of a dogging device according to the invention. 
       FIG. 10  is a side view of a dogging yoke that includes support elements in accordance with the invention. 
       FIG. 11  is a sectional view taken on the line XI—XI in FIG.  10 . 
       FIG. 12  is a sectional view taken on the line XII—XII in FIG.  10 . 
       FIG. 13  is a sectional view taken on the line XIII—XIII in FIG.  10 . 
       FIG. 14  is a sectional view corresponding to  FIG. 11 , with the support element deactivated. 
       FIG. 15  is a sectional view corresponding to  FIG. 12 , with the support element deactivated. 
       FIG. 16  is a horizontal sectioned view of a pair of dogging yokes and the side edges of a booklet with the support element deactivated. 
       FIG. 17  is a sectioned view corresponding to  FIG. 16 , with the support element activated. 
   

   DESCRIPTION OF PREFERRED EMBODIMENTS 
   Shown in  FIG. 1  is a casing  1  that consists of paperboard and/or plastic and which has been folded from a flat state to the shape shown in  FIG. 1 , so as to form two casing sides  2  and  3  and a spine  4 . An adhesive  5  is applied to the inner surface of the spine  4  and possibly also to those parts of the casing sides  2  and  3  that lie close to the spine. The adhesive  5  may have different forms and compositions, although it will preferably consist of a strip of hotmelt glue of essentially rectangular cross-section, i.e. a glue which takes a solid state at room temperature and a semi-solid state or liquid state when heated to a higher temperature. 
   A sheet bundle  4  consisting of a plurality of paper sheets is shown to be inserted into the casing in  FIGS. 1 and 2 , such that one side edge of respective sheets in said bundle rests against the surface of the binder  5  distal from said spine. The casing and its inserted sheet bundle are intended to be fed into the machine illustrated in  FIGS. 3-5  and treated in this state., so as to affix the bundle to the casing through the medium of the binder  5 . 
   The machine illustrated in  FIGS. 3-5  is intended for the production of booklets, each being of the kind that consists of a casing  1  and a sheet bundle  6  inserted into said casing in the manner shown in  FIGS. 1 and 2 . The sheet bundle  6  need not be jogged upon insertion into the machine, and neither need it be orientated in the finely desired position in the casing.  FIG. 1  shows this state. 
   The main components of the machine include a magazine  8 , in which the casings  1  and inserted sheet bundle  6  are placed, an activator  9  for heating and possibly later cooling the binder  5 , and a collecting space  10  for collecting finished booklets. The machine also includes devices for conveying the casings and their inserted sheet bundles from the magazine  8  to the collecting space  10 , and a sheet jogging device (FIG.  5 ). In order to make the machine as compact as possible and to facilitate placement of the casings and sheets in the machine and the removal of finished booklets from said machine, the magazine  8  and the collecting space  10  have been placed immediately by the side of each other and immediately above said activating device  9 . 
   The magazine  8  is delimited by a parallelepipedic space that contains a conveyor which comprises two mutually identical and parallel dogging devices  13  and  14  which delimit two side walls of said space, and a bottom plate  15  affixed to the machine frame. Each dogging device  13 ,  14  comprises two endless and flexible toothed belts  16 , and wire yokes  17  attached to the belts and extending therebetween. The belts  16  are driven by toothed wheels  18 , of which both of the toothed wheels of each conveyor  13 ,  14  are driven by a shaft  19 , said two toothed wheels being seen furthest to the right in FIG.  3 . The shafts  19  are continuously rotated in one direction by an electric motor  20 , via co-acting conical gearwheels or pinion wheels  21   a  and  21   b.    
   Each dogging device  13 ,  14  includes two mutually adjacent yokes  17  spaced apart at a distance that exceeds the maximum occurring thickness of a casing  1  and its inserted sheet bundle  6 , said adjacent yokes  17  forming a compartment. This means that two or more casings and their respective sheet bundles of the minimum occurring thickness will be accommodated between these two yokes. Each casing  1  and its inserted sheet bundle  6  are placed down in the magazine  8  between a pair of mutually adjacent yokes  17  in each dogging device  13 ,  14 , with the spine  4  facing downwards and positioned horizontally, and will be supported by and dogged by said yokes as the mutually facing parts of the conveyors are moved synchronously to the right in  FIG. 3  with the spines  4  of said casings  9  against the plate  15 . 
   Two arms  24   a  are attached to a horizontal shaft  23  immediately to the right of the conveyors  13  and  14 . These arms  24   a  can be swung backwards and forwards by means that will be described below with reference to  FIG. 5. A  suction cup  24  is mounted on the free end of each arm  23 . 
   When a casing  1  and its inserted sheet bundle  6  has been moved so far to the right in the magazine as to leave the plate  15 , it will fall down through a short distance into abutment with a plate  25  that forms a part of the machine frame. In so doing, the spine  4  of the casing actuates a switch  26  which briefly stops the movement of the conveyors  13 ,  14  and which sends an impulse to a suction pump (not shown) connected to the suction cups  24 , causing said suction pump to work. Concurrently herewith, the swinging shaft  23  moves the suction cups  24  onto the casing resting on the plate  24 , therewith securely gripping the casing by suction. When the shaft  23  is then swung in the opposite direction, the suction cups  24  move the casing  1  and its sheet bundle  6  to the right in  FIG. 3 , wherewith the casing leaves the plate  25 . When the suction cups  24  then release their grip on the casing  1 , the spine  4  of the casing will come into abutment with two stops  27  on a hoist that consists of two arms  28  provided with blocks  29  that are intended to run vertically on rods  30  mounted in the machine frame and extending along practically the full height of the machine. The two arms  28  and the blocks  29  are mutually connected by means of an angled arm  31  whose ends are attached at two flexible toothed belts  32  and  33  which are driven by a motor  22  that has a reciprocatingly rotating outward shaft, via shafts driven thereby, such as the shafts  34   a  and  34   b  and toothed wheels. The toothed belt  32  extends between toothed wheels  34  and  35 , while the toothed belt  33  extends between toothed wheels  36 - 39 . 
   Immediately after the casing  1  and its inserted sheet bundle  6  has been transferred to the stops  27  on the hoist  28 ,  29 ,  31 , where said casing is held vertically by the arms  28 , the toothed belts  32  and  33  move the hoist down to the lower part of the machine. 
   As the hoist  28 ,  29 ,  31  reaches its bottom terminal position, the spine  4  of the casing  1  will come into contact with two frame-carried surfaces  43  which slope inwardly and downwardly. After sliding on the surfaces  43 , the casing  1  will be pushed by the stop plate  42  onto the conveyor arrangement  44  and their gripped by dogging devices  46  and  47 . These dogging devices are essentially identical to the dogging devices  13 ,  14  but with the exception that these latter devices have a longer horizontal extension. The dogging devices  46 ,  47  are mounted on shafts  60  that are driven step-wise by a motor  61  and in directions opposite to the dogging devices  13 ,  14 . The motor  61  includes an eccentric disc  61   a  which swings a catch hook  63  backwards and forwards through the medium of an arm  62 . The catch hook  63  engages with a catch wheel  64  which causes a shaft  65  connected there to, to to move stepwise in a counter-clockwise direction in FIG.  4 . The shaft  65  drives the shaft  60  through the medium of conical pairs of toothed wheels  21  and a roller  50  extending therebetween. 
   The conveyor arrangement  44  includes at least one endless and flexible conveyor belt  52  made of some suitable heat-conducting material, such as Teflon® the upper part of which moves stepwise to the left in  FIG. 3  with the same speed as the dogging devices  46  and  47 . The conveyor arrangement  44  also includes the roller  50  and a roller  51  on which the belt  52  is mounted. 
   The activating device  9  is situated between the belt runs and projects sideways beyond said belt, where it is fastened to the machine frame. The device  9  includes a heating plate  53  which emits sufficient heat to melt, via the belt  52 , the strip of hotmelt glue applied to the casing to a semi-solid or almost liquid state. The bottom run of the belt  52  abuts with and slides against the heating plate  53 . If the binder is of a kind other than hotmelt glue, the construction of the activating device is adapted accordingly. In an alternative embodiment, the belt  52  may be constructed to constitute a heat source or some other binder activating means. 
   Mounted between both runs of the belt  52  to the left of the heating plate  53  in  FIG. 3  is a cooling plate  54  against which the upper surface of the upper run of the belt abuts and slides. The degree of cooling afforded by the underside of the plate  54  can be enhanced by providing said plates with cooling fins and/or a cooling fan or blower can be installed in the machine. Alternatively, the plates  54  may be equipped with channels for cooling water. 
   The dogging devices  46  and  47  and the belt  52  that runs at the same speed as said devices move the casing  1  and its inserted sheet bundle  6  to the left. During this movement, the hotmelt glue is brought to a semi-solid or to an almost liquid state and the sheet bundle  6  falls down into the hotmelt glue towards the spine  4 . As the casing  1  and its sheet bundle  6  move, the sheets in said bundle are jogged relative to the casing by a sheet jogging device. As the sheets are jogged, the casings and sheet bundles therein are forced in a direction towards the heating plate  53 , such as to increase the transfer of heat from said plate to the spine  4  of the casing, via the belt  52 . 
   The reason why the casings  1  are not in direct contact with the heating plate  53  during their movement over the plate, is because friction between the casings and plate could possibly score or dirty the outer surfaces of the casing spines  4 , which is a risk particularly when the spines have colour printing thereon. 
   When the casing  1  and its inserted sheet bundle  6  has passed the heating plate  53 , the casing and its contents is passed over the cooling plate  54 , still by the dogging devices  46 ,  47  and the belt  52 , wherewith the hotmelt glue is brought at least to a partially solid state. When the casing has passed the plate  54 , the glue will have taken a substantially solid state. 
   When the casing  1  and the sheet bundle  6  bound therein, i.e. the finished booklet, has passed the conveyor arrangement  44 , the booklet will fall down into a chute  55  at the left end of the arrangement  44 . The booklet is conveyed from the chute  55  to the collecting space  10  by the conveyor arrangement  12 . 
   Subsequent to the booklet having arrived in the space  10 , the hoist, i.e. the arrangement  12 , is lowered to collect a further booklet lying in the chute  55 . 
     FIG. 5  shows the sheet jogging device  13 , which includes three plates  85 ,  86  and  87  and drive means therefor, as indicated in  FIG. 4 , of which plates at least the plate  85  is shown in  FIG. 3. A  motor  88 , which may be the same motor as that referenced  61 , is provided with an eccentric disc  88   a  on which there is pivotally mounted an arm  89 . The arm  89  is pivotally connected to an arm  90  which is pivotally connected to pivot elements  91  fixedly connected to the pivot elements  92  and shafts  93 , which are pivotally mounted in beams  94  on the machine frame. Pivot elements  92  identical to the pivot elements  92  are pivotally connected there to, to by means of arms  104 . 
   The shafts  93  are provided with cranks  96  mounted in blocks  95  affixed to the plates  85 - 87 . The upper part of each crank  96  is fastened in a shaft  97  which extends through a beam  98  affixed to the plate  87 . Each shaft  97  is connected above the beams  98  with a screw  100  that engages with a nut  99  affixed to the upper side of said beam  98 . The nut  99  is non-rotatably attached to the machine frame, but can be displaced axially in relation thereto. 
   As the motor  88  rotates, the plates  85  and  86  move towards and away from each other in a horizontal direction at a frequency determined by the speed of the motor. 
   The plates will move concurrently in a direction towards and away from the activating device  9 , owing to the fact that the axially immovable screws  100  will be screwed into and out of the nuts  99  as the shafts  97  rotate, so as to move the nuts axially and therewith carry the beams  98  and the plate  87 . Movement of the plates  85 - 87  takes place immediately prior to and during activation of the binder  5  in the casings  1  by the activating device  9 , partly to jog the sheets  6  relative to one another and relative to the casings and partly to urge the casings and their sheets against the activating device  9  (which only the plate  87  does) so as to increase the transfer of heat to the binder. 
   One of the shafts  97 , which is extended and referenced  97   b , includes a pivot element  101  that is pivotally mounted in a rod  102 , which is pivotally mounted in an arm  103  attached to one end of the shaft  23 . As the shaft  97  rotates forwards and backwards, the shaft  23  is swung alternately in a clockwise and counter-clockwise direction, so as to move the suction cups  24  towards and away from a casing  1  resting on the plate  25 . 
   Up to this point, the described machine for the production of booklets corresponds to the machine described in the earlier mentioned publication WO91/04159 and is thus known to the art. Hereinafter, there is described a specific design of the conveyor  44  that is constructed to move the booklets over the glue-activating device  9 , this design being in accordance with the present invention. In order to facilitate an understanding of the invention, reference is first made to  FIG. 6  which illustrates schematically how the booklets are disposed in a conveyor of conventional construction. The figure is a vertical sectioned view taken longitudinally through a part of the dogging devices  47 ′ of the conveyor, said section being lain adjacent one side edge of each booklet  1 ′. One side edge of each booklet  1 ′ is located between two adjacent dogging yokes  105 ′ of the dogging device  47 ′. The distance between two dogging yokes  105 ′ is greater than the thickness of each booklet  1 ′. As a result, the booklets  1 ′ will curve between the dogging yokes  105 ′, as evident from the figure. The drawbacks in this case have been discussed in the introduction to the description. 
     FIG. 7  is a corresponding view illustrating a dogging device constructed in accordance with the invention. A support element  106  is attached at each dogging yoke  105  in a manner described in more detail hereinafter. Each support element  106  clamps respective booklets against the preceding or succeeding dogging yoke  105 , so that the booklet will be orientated in a flat, vertical position. 
     FIG. 8  is a view of the arrangement shown in  FIG. 7  from above.  FIG. 8  also shows how the opposing end edges of each booklet  1  are clamped between dogging yokes  107  and associated support elements  108  of a second dogging device  46  situated centrally opposite the first dogging device  47 . 
     FIG. 9  is a perspective view of part of the dogging device  47  shown in FIG.  7 . Each dogging yoke  105  has the form of an elongated, flat plate which has at its inner end a collar  109  that extends perpendicular to the plate. Each dogging yoke  105  has at its top and bottom inwardly of the collar  109  a projection  110  which slides against a respective guide body  111 ,  112  as the dogging yoke  105  moves. The dogging yokes  105  are disposed sequentially in an endless belt that is driven by a shaft  60  via top and bottom toothed drive bodies  113 ,  114 . Each drive body  113 ,  114  engages a respective projection  110  on the dogging yoke. It will be seen from the figure that a support element  106  is arranged at each dogging yoke  105 . 
     FIG. 10  shows a dogging yoke  105  and a support element  106  attached thereto.  FIGS. 11 ,  12 ,  13  are sectioned views through the dogging yoke of  FIG. 10 , taken on the lines XI—XI, XII—XII and XIII—XIII respectively. The dogging yoke  105  has the form of an elongate, generally rectangular plate, and the support element  106  has essentially the same size and shape. In the figure, the support element  106  is situated in front of the dogging yoke  105 , this latter thus being substantially hidden from view. The collar  109  of the dogging yoke  105  Is arranged to the right of the figure (see FIG.  11 ). The support element  106  is fastened to the dogging yoke  105  in a hinge-like manner, by virtue of three tabs  115 ,  116  and  117  on the support element  106  extending through respective slots  118  and  119  in the collar  109  of said dogging yoke (see FIGS.  11  and  13 ). The two outermost tabs  115  and  117  define with the main body of the support element  106  an angle that is slightly greater than 90°. These two tabs  115 ,  117  are relatively long and contribute towards activating/deactivating the support element. The centre tab  116  is divided into three parts  116   a ,  116   a ,  116   b . The two outer tabs  116   a ,  116   a  extend straight through the slot  119 , whereas the centre tab  116   b  is angled at about 90° in the opposite direction compared to the tabs  115 ,  117  (see FIG.  13 ). The tab parts  116   a ,  116   a ,  116   b  are intended primarily for contributing towards and holding the support element attached to the dogging yoke. Furthest out at each end of the dogging yoke  105  are the two projections  110  by means of which the dogging yoke is caused to move. 
   The support element  106  also includes two tongues  120  and  121  formed by making slots in the material of the support element. The manner in which these tongues  120  are formed will be more apparent from FIG.  12 . The tongue  120  is bent out from the remainder of the plane of the support element and there defines an angle to said plane when no load acts thereon. The material from which the dogging yoke is made and the thickness of said material are chosen so as to enable the tongue  120  to be folded down towards the plane of the dogging yoke  106 , about the bending line  122 . The resistance to bending will therewith exert a counter-force that induces a spring effect. 
   The resilient tongues  120 ,  121  of the support element shown in  FIGS. 10-13  are in a relaxed or non-loaded state. The resilient tongues  120 ,  121  are subjected to load, by bending the tabs  115 ,  117  downwards/inwards against the collar  109  of the dogging yoke.  FIG. 14  is a sectioned view corresponding to FIG.  11  and shows how the support element  106  takes a position parallel with and adjacent to the dogging yoke  105  subsequent to the tab  115  having been folded down. This takes place whilst overcoming the flexural resistance of the resilient, or springy, tongues  120 ,  121 . These tongues will then take the position illustrated in  FIG. 15 , said figure being a sectioned view corresponding to the view in FIG.  12 . 
   The support element  106  is therewith deactivated in the position shown in FIG.  15 . The support element  106  is in an activated state in FIG.  12 . 
   In the deactivated state of the support element, one side edge of a booklet  1  can be inserted with clearance between two mutually adjacent dogging yokes  105 , as illustrated in FIG.  16 . In this illustration, the support element  106  is locked in its position adjacent the dogging yoke  105 , by virtue of the tabs  115 ,  117  being locked in the position illustrated in FIG.  14 . 
   Correspondingly,  FIG. 17  shows the case when the support element  106  is activated by releasing the lock on the tabs  115 ,  117 . The tongues  120 ,  121  then strive to press the support element  106  out towards the position illustrated in FIG.  12 . As will be evident from  FIG. 17 , movement of the booklet  1  is stopped and the booklet therewith clamped between the support element  106  and the opposing dogging yoke  105  and is pressed against the latter by the springy tongues  120 ,  121 . 
   Locking of the tabs  115 ,  117  takes place at the beginning of the movement of a dogging yoke  105  in the transport direction. This takes place by virtue of ridge means (not shown) arranged on the support bodies  111 ,  112  at their commencement on a level corresponding to the level of the tabs. The ridge elements thus urge the tabs into the position shown in  FIG. 14 , therewith creating the clearance shown in FIG.  16 . After a short time, the tabs  115 ,  117  will have passed the ridge elements and go free so that the resilient tongues  120 ,  121  will be activated, as in FIG.  17 . Clamping of the booklets is released in the final stage of transportation, by virtue of the dogging yokes deviating from the direction of transport as they move around the end of respective support bodies  111 ,  112  located where transportation terminates. 
   The dogging yokes  105  and the support devices may conveniently be made of a plastic material.