EP0144207A2

EP0144207A2 - Improved franking machine

Info

Publication number: EP0144207A2
Application number: EP84308224A
Authority: EP
Inventors: Alan John Harry
Original assignee: Francotyp Postalia GmbH; PA Consulting Services Ltd
Current assignee: Francotyp Postalia GmbH
Priority date: 1983-12-02
Filing date: 1984-11-27
Publication date: 1985-06-12
Also published as: GB8332241D0; EP0144207A3; GB2150497B; YU202984A; CA1234013A; JPS60138695A; GB2150497A; PL250665A1

Abstract

A franking machine having a printed head and a platen between which mail can be located for impressing a franking mark thereon, by relative movement of the head and platen, is characterised by the printing head including a retentive pad porous rubber stamp which is either impregnated with ink for life or has a reservoir and filler into which ink can be poured from time to time and is adapted to supply ink to the retentive pad.

Description

Field of Invention

This invention concerns franking machines.

Background to the Invention

In general franking machines use complex and expensive printing systems, and it is an object of the present invention to provide an improved printing system for a franking machine.

Summary of the invention

According to one aspect of the present invention in a franking machine there is provided a printing head and a platen between which mail can be located for impressing a franking mark thereon, by relative movement of the head and platen, wherein the printing head includes a retentive pad porous rubber stamp which is either impregnated with ink for life or has a reservoir and filler into which ink can be poured from time to time, and adapted to supply ink to the retentive pad.
The inked for life pad typically comprises two layers of porous material one layer having large pores and the other, forming the printing surface, having much smaller pores. In such a device the larger pored layer serves as an ink reservoir and is impregnated with ink during manufacture. US Patent 3, 971, 315 describes such a Where a separate reservoir is provided this is conveniently located above the pad so that ink can flow down therefrom and the reservoir includes a filler by which additional ink can be supplied thereto to replenish the supply.
According to a preferred feature of the invention in a franking machine in which the franking mark includes constant data and changeable data, an inked for life retentive pad porous rubber stamp may be employed for the constant date and a reservoir supplied retentive pad porous rubber stamp may be employed for the changeable data.
In a preferred embodiment the changeable data is contained on one or more endless rubber belts or around rubber tyred wheels and an inking reservoir is provided adjacent the belt or tyre so that ink is transferred to the latter as the belt or tyred-wheel is rotated to select different characters or groups of characters therearound for printing.
In such a preferred embodiment the rubber belts can be relatively thin so as to allow them to pass around driving wheels and the like since the regular inking of the belt will ensure that there is always sufficient ink on the surface thereof to provide for a good impression.
The expression constant data is intended to cover information such as the name and address of a business which owns the franking machine or advertising or promotional material which is to be included on mail alongside the date and town of posting and the value of the postage rate applicable to the packet or envelope.
The expression changeable data is intended to cover information such as the date and the amount of the postal rate applicable to the packet or envelope.
According to a further aspect of the invention, where constant and changeable data bearing inked printing devices are contained in a single printing head of a printing machine at least that part of the head containing the constant date printing device is movable relative to the remainder of the head to permit the device containing the constant data to be replaced to allow the constant data to be changed.
According to a further aspect of the invention where constant and changeable data bearing inked printing devices are contained in a single printing head of a franking machine which includes a platen on which mail to be franked is placed below the printing head, at least a portion of the platen which aligns with the printing device containing the constant data is movable or removable, to give access to the device containing the constant data to allow the latter to be removed and replaced with another containing different constant data.
In an arrangement where only the constant data device is accessible by movement of a portion of the head or platen without giving access to the printing device or devices containing the changeable data, the franking machine is rendered more tamper proof and less likely to be the subject of unauthorised adjustment to secured franking without payment.
According to a further aspect of the invention in a franking machine incorporating a printing head containing devices for printing constant and changeable data onto packets and envelopes and which further includes a platen on which the packets and envelopes are located for franking, each of the printing devices comprises a self inking or inked for life printing device so that the printing head can be of simple construction and will contain few moving parts.
The invention will now be illustrated by way of example with reference to the accompanying drawings in which

Figure 1 is a perspective view of a printing head and platen mechanism embodying features of the invention;
Figure 2 is a second perspective view of the mechanism of Figure 1 from a different angle;
Figure 3 is a side view of the mechanism of Figure 1 viewed in the direction of arrow 3 and with the sideplate removed;
Figure 4 is a similar side view of the mechanism shown in Figure 1 viewed from the opposite direction to that of arrow 3 and with the sideplate removed;
Figure 5 is a diagrammatic side view showing part of the printing and indexing mechanism contained within the printing head of the mechanism shown in Figures 1 and 2;
Figure 6 is a top plan view of the mechanism shown in Figure 1;
Figure 7 is an underside view of the same mechanism;
Figure 8 is a top plan view, partly diagrammatic in format, of a complete printing head assembly for a franking machine incorporating printing head mechanisms such as shown in Figures 1 to 7;
Figure 9 is a front elevation of the apparatus shown in plan in Figure 8 with protective covers removed to illustrate the interior of the printing heads;
Figure 10 is a view in the direction of arrow 10 in Figure 9 with some of the elements removed for clarity to illustrate the indexing and printing mechanism within one of the printing head mechanisms of Figure 9;
Figure 11 is a side view of the apparatus shown in Figure 9 viewed in the direction of arrow 11 in Figure 9 illustrating relative layout of component parts;
Figure 12 illustrates the interior of a drive wheel ratchet having a uni-directional characteristic, and
Figure 13 is a cross-section of the drive wheel ratchet arrangement of Figure 12.
Figure 14 is an underside view of the printing head of Figures 1 - 7 shown partly in cross-section on a plane through the axis of rotation of the shafts 80, 82; and
Figure 15 is an underside of the platen and head assembly of Figures 1 - 7 with the coverplate 52 of Figure 7 removed.

Detailed description of drawings

In Figures 1 and 2 there is shown a basic printing head mechanism of the type which can be incorporated into a franking machine or the like. The mechanism shown in Figures 1 and 2 and the subsequent five Figures is intended to illustrate the principle of operation and construction more clearly than is the case when the components are miniaturised and compacted more densely than in the mechanism shown. A final form of the apparatus illustrating the use of the same type of printing head in a parallel multi-head arrangement in a franking machine is shown in later Figures.
In the drawings a baseplate 10 serves as a support for two sideplates 12 and 14. A drive motor and gearbox assembly (not shown in detail) 16 is attached to and extends beyond the side wall 14 and serves to rotate a drive shaft 18 carrying a main print head operating cam 20 and a supplementary switch-actuating cam 22.
Also between the two sidecheeks 12 and 14 extends a second shaft or rod 24 which is parallel to but spaced from and to the rear of the drive shaft 18.
The printing head comprises a generally rectangular housing 26 which is pivotally attached at 28 on the one side and at a similar point (not visible in the drawings) on the other side of the housing 26 by means of stub- axles, to opposite side members 30 and 32 respectively of a yoke assembly generally designated 34.
The latter is relatively freely floating in that it is secured to the baseplate 10 through a lost motion connection best seen in Figures 3 and 4. This comprises an upstanding pin 36 having an enlarged head 38 which holds captive the generally flat plate section of the yoke assembly 34. The latter includes an aperture (not shown) which is oversize relative to the diameter of the pin 36 so that the plate of the yoke assembly 34 can, in fact, tilt to one side or the other as well as in a generally up and down manner relative to the baseplate 10.
The yoke assembly is held in place by means of a spring 40 located between a point of attachment at 42 in the middle of the plate of the yoke assembly 34 and attached to a fisher plate 44 which itself is threaded on the rod 24 extending between the two sidecheeks 12 and 14. The spring is selected so as to still be in tension when the side arms of the yoke assembly 30 and 32 engage the underside of the axle 18 which is the normal centralised position for the assembly under the action of the spring 40.
The yoke assembly and therefore the printing head 26 can be moved in a downward direction for printing by rotation of the cam 20 to deflect the yoke 34 in the direction of the arrow 46 (see Figure 3).
The printing head includes a print face 48 containing characters which, if inked, will leave a suitable impression on an envelope or letter situated thereunder and aligned with and below the print face 48 is a platen 50 which is located in position by means of an underplate assembly 52 secured in position by means of four screws as can best be seen in Figure 7.
Removal of the plate 52 gives uninterrupted access through an aperture (not shown) in the baseplate 10, to the print face 48 to facilitate checking, cleaning and replacing members of the print head assembly.
The orientation of the print head 26 relative to the yoke arms 30 and 32 is maintained by means of at least one spring best seen in Figure 1. The spring includes two radial arms 52 and 54 and is looped at its centre around the protruding end of the stub-shaft 28 the outboard end of which is enlarged to prevent the spring loop from leaving the stub-shaft.
The outboard ends of the radial arms 52 and 54 are secured on the one hand in an aperture 56 in the arm 30 and around a fixed stand-off 58 attached to the side of the print head housing 26.
A similar spring (not shown) is provided on the other side of the housing 26 between it and the other arm 32 of the yoke assembly.
The springs are selected so as to hold the print head housing 26 in the orientation shown in Figures 1, 2 and 3. Any attempt to tilt the head 26 in either direction denoted by the double-headed arrow 60 in Figure 3 will be resisted by the spring and-the restoring force stored in the spring will tend to return the housing 26 to the orientation shown in Figures 1 to 3 as soon as any force tending to tilt the housing 26 relative to the yoke assembly is removed. Such a tilting force is, of course, exerted on the printing head assembly 26 in the event that an envelope or package is located below the print face 48 which is not of uniform thickness so that part of the print face is prevented from travelling in a downward direction by the same amount as another part of the print face.
The interaction of the two arms 30 and 32 with the rod 18 serves to centralise the yoke assembly and therefore the housing 26. However, once the cam 20 has rotated so as to depress the yoke assembly in the direction of the arrow 46, the interaction between the arms 30 and 32 ceases and the yoke assembly becomes freely floating by virtue of the fact that the point of contact between the cam 20 and the yoke plate, the point of attachment 42 of the spring 40 with the yoke plate and the rear mounting pin 36 are all on a straight line which is substantially perpendicular to the axis of pivoting of the head 26 relative to the yoke assembly and established by the stub- shafts of which one is denoted by reference numeral 28.
As a consequence the head 26 can, relative to the baseplate 10 and therefore the platen 50, tilt not only in the direction of the double-headed arrow 60 but also from side to side as indicated by the curved arrows 62 and 64 in Figure 1. The printing head can therefore accommodate gross unevenness in a packet or envelope located therebelow.
The printing head itself includes four endless belts of which one is shown at 66 in Figure 5, arranged in parallel-spaced arrangement within the head. Each follows a generally oval path and at its lower end passes around an inking reservoir and transfer pad not shown in detail but designated by reference numeral 68. To this end the material from which the endless loop 66 is formed is preferably porous at least to certain printing inks and forms a so-called retentive pad porous rubber printing medium. The belt or loop 66 is formed around its external surface with a series of upstanding segments such as 70 and 72 each of which can if desired carry a character in relief which when the material forming the belt or loop 66 is saturated with ink will form an impression of the character on-a sheet of paper or the like located below the printing head in the position designated in dotted outline at 74. To this end, an opening is provided in the underside of the housing through which the lowermost of the segments 70, 72 etc can just protrude and in the illustration this is denoted by reference numeral 76.
At its upper end the belt passes around a driving pulley 78 which is either mounted directly onto one of the two head driveshafts 80 or 82 or is connected thereto through the intermediary of a uni-directional clutch (to be described). In Figure 5 the driving wheel 78 can be thought of as comprising the shaft 80 or mounted thereon.
Drive for the shaft 82 is provided by a first electric motor 84 the output shaft of which includes a toothed pinion 86 which meshes with a gearwheel 88 which in turn drives a second toothed pinion 90 for driving a larger diameter gearwheel 92 splined or otherwise secured to the shaft 82.
For clarity, the second motor and gear train for driving the other aligned but separate shaft 80 are not shown in Figures 1 and 2. However, it is to be understood that the second motor is mounted back-to-back and may be in axial alignment with a first motor and a second gear train similar to that transmitting drive between the first motor and the shaft 82 is provided between the second motor (not shown) output shaft and the shaft 80.
Each of the two shafts 80 and 82 extends into the housing 26 by a sufficient amount to almost touch the opposite end of the other shaft. However, the two shafts are entirely separate from a rotational point of view.
Within the housing 26, two of the four endless belts such as 70 are driven by one of the shafts 80 and another two are driven by the shaft 82.
As will hereinafter be described, one of the endless belts in each pair is driven through a uni-directional clutch so that rotation of the shaft, for example, 80, in one direction will rotate both of the endless belts associated therewith but in the other direction will only drive the endless belt which is directly connected to the shaft or to a driving wheel itself non-rotatably secured on the shaft. Consequently, the two endless belts can be independently set so as to present selected characters such as 76 for printing by first of all rotating both of the endless belts in one direction until the first character associated with the clutched belt is in position and thereafter rotating the shaft in the opposite sense until the other character associated with the fixed wheel or belt has been moved into position.
The other pair of endless belts can be set in a similar manner by rotation of the other motor, first in one direction and then the other.
Although not shown, it is to be understood that a separate uni-directional clutch may be provided for each drive to each of the belts so that both belts are completely independent and rotation of the shaft such as 80 in one direction will only cause one of the belts to be rotated whilst rotation in the other direction will cause the other belt to be rotated.
It is, of course, not easy to see which particular character has been displayed in the window on the underside of the printing head for any particular belt and to this end a toothed indexing wheel is associated with each individual belt. One such wheel is shown at 94 in Figure 5. The spacing between the teeth around the indexing wheel 94 is commensurate with the spacing between the upstanding segments such as 70, 72 around the endless belt 66 so that as the belt rotates so the indexing wheel must rotate by a corresponding number of segments. The indexing wheel 94 includes one or more electrical contacts (not shown) which, as the wheel 94 is indexed, make different combinations of connection between a plurality of conductors designated by reference numerals 96 and 98 by way of example only, carried by a conductor card 100 sandwiched between the index wheel 94 and the next index wheel along. These cards are more clearly shown in Figure 1 and it will be noted that flying leads such as 102 are connected to the conductors such as 96, 98 etc for conveying the pattern of electrical connections to a microprocessor or the like to establish the precise positions of the four index wheels 94. By appropriately coding the electrical connections, so an electrical signal can be derived indicative of the angular position of each of the four wheels 94 which therefore corresponds to the rotational position of the associated four endless belts 66 and therefore the four characters or groups of characters contained by the belts in the window in the underside of the printing head 26.
The window and surrounding framework constitutes a print face 48 of Figure 3.
In Figures 2, 3 and 6 the bundle of conductors to the conductor cards 100 are only shown leading to one of the cards. In practice, a single bundle would in fact be led to and make connection with each of the cards as is shown in Figure 1.
Reverting to Figure 1, a microswitch 104 is shown mounted close to the second cam 22 mounted on the shaft 18 with the microswitch actuating lever 106 acting as a cam follower. The cam is shaped and fitted to the shaft 18 so that the microswitch is operated once every revolution of the shaft 18 and is opened (or closed) as required at a position in which the lobe of the cam 20 is furthest from the plate of the yoke assembly 34.
The design of print head assembly shown in Figures 1 to 7 is eminently suitable for incorporation into a franking machine in which a plurality of such head assemblies are located side by side. Each different head assembly can then be dedicated to one particular task associated with the franking of mail and appropiate characters and printing devices are located in each such dedicated printing head assembly.
Arrangements such as this is shown in Figure 8 where four such printing heads are mounted at the end of four freely floating yoke or arm assemblies. The four printing heads are designated 108, 110, 112 and 114 and their respective support arms by the reference numerals 116, 118, 120 and 122.
Actuating cams, each corresponding to the cam 20 of Figure 1, are denoted by reference numerals 124, 126, 128 and 130 respectively.
The lost motion free pivot points corresponding to the rear pin 36, 38 of Figure 3 are denoted by reference numerals 132, 134, 136 and 138 respectively.
Springs corresponding to the spring 40 of Figure 3 are shown at 140, 142, 144 and 146.
The cams 124 to 130 are all mounted on a common shaft 148 and drive therefor is derived therefrom.a motor and gearbox assembly (not shown) similar to the item 16 of Figure 1.
Figure 9 illustrates the assembly of Figure 8 from the front as an elevation thereof in the direction of arrow 8.
Print head 114 and 112 are each an ink-loaded porous rubber stamp having a printface 115 and 113 respectively containing characters or indicia which when urged into contact with a sheet of paper such as the outside of an envelope or packet will produce a pattern of information thereon.
The print heads 110 and 108 respectively are constructed basically in the same way as the head shown in Figures 1 to 7 in that they comprise a series of endless belts (see Figure 11) of which one is designated 148 which have outwardly protruding segments containing characters for printing. Each of the belts can be indexed by appropriate rotation of one or the other of two drive shafts 150 and 152 which are themselves driven by toothed wheels 154 and 156 respectively themselves driven by worm gears 158 and 160 respectively on the outward shafts of two motors 162 and 164.
The print head 110, however, is not motor-driven but is manually rotatable to adjust the print head characters and to this end two thumbwheels 166 and 168 are provided which have external serrations such as at 170 which engage appropriately toothed wheels 172 and 174 respectively. The toothed wheels just referred to serve to drive one or other of two short axles (not shown) to rotate one or other of the endless belts such as 176 and the endless belts are engaged by externally segmented indicator wheels of which one is designated at 178 each having external protrusions for engaging in the segments around the endless belt 176 so as to rotate therewith.
By providing one indicator wheel for each of the endless belts 176 etc, so the characters lined up in the printing station by adjustment of the four endless belts 176 etc can be displayed on the appropriate indicator wheels behind a window 180 provided in a front inclined wall of a housing 182 which covers the whole assembly.
The franking machine thus incorporates three different types of printing head within the overall assembly, two in which the printing plates are self-inked for life and two in which the endless belts are of a porous material and are replenished by ink from a reservoir such as at 184 (see Figure 10).
Figure 11 shows the layout of the various parts making up the overall assembly at least insofar as the print head 108 is concerned. To this end there is a yoke 116 and spring 140, operating cam 124 on shaft 148 and a stop shaft 186 (not shown in Figure 8) extends across and prevents upward movement of the yoke assembly 116 beyond a certain amount under the action of the spring 140.
The encoder assembly 188 corresponds to the encoder cards 100 of Figures 1 to 7 embodiment and shown diagrammatically at 190 is one of the toothed wheels containing the electrical conductors which set up the contacts and circuits on the encoder boards and which rotates with rotation of the endless belt 148.
Below the printing stage is shown a soft resiliently deformable pad 192 to absorb unevenness and thick contents of envelopes and packets. A stop 194 running along the length of the base 196 behind the platen area 192 serves as a guide as to where the envelope, packet or the like should be pushed before the printing head is lowered.
Figures 12 and 13 illustrate a uni-directional clutch arrangement in which a shaft 196 has secured therein a diametrically extending dog 198 for engaging the inside of an annulus 200 which is formed as a circular internal ratchet. The dog 198 is slidable axially within the shaft 196. As the shaft 196 rotates in the direction of the arrow 202, drive is transmitted between the end 204 of the dog 198 and one of the teeth of the ratchet. Rotation of the shaft 196 in the opposite direction to arrow 202 causes the dog to ride up the inclined surface 206 and to enter the cutaway region 208 on the opposite side of the ratchet wheel so that there is no tendency for any rotational drive to occur between the shaft 196 and the internal ratchet wheel 200.
Figure 14 shows more clearly than the views of Figures 1 - 7 the internal detail of the printing head 26. The shafts 80, 82 are formed with reduced axially parallel grooves at their inboard ends one of which is shown in the cross- sectioned half view of Figure 14, at 210. Rolling elements such as 212 are located in the grooves and support an annular member such as at 214 forming part of one of the driving wheels 78. The design of the grooves and rolling elements and shape of the interior of the annular member 214 is such that rotation of the shaft in one direction transmits drive to the driving wheel 78_' whilst in the other direction, to the driving wheel 78". Endless bands containing printing characters are fitted arround the driving wheels 78 as previously described.
An electrical position-indicating signal is obtained from the rotation of the indexing wheel 94 co-operating with the driving wheel 78', 78" etc. In the view shown in Figure 14 indexing wheel 94' co-operates with driving wheel 78'. On the lefthand side in Figure 14 the indexing wheels etc are shown in cross-section and the sliding electrical contact between the wheel and the conductive tracks on its associated card 100'. However, in the non- section half of Figure 14 there can clearly be seen at 216 and 218. The indexing wheels 94', 94" etc are freely rotatable above their central supporting axle 220 whilst the cards are non-rotatable relative thereto.
Figure 15 demonstrates how, after removing the coverplate 52 (shown in Figure 7) the underside of the printing head 26 can be clearly seen to permit the semi-permanent printing matter to be changed if required. This is shown as the rectangular cross-hatched region 222 defining the aperture 224 through which the variable printing characters protrude. The region 222 is held in place by six screws 226 and is replaceable by other surrounds as required by removing the screws 226.

Claims

1. A franking machine having a printing head and a platen between which mail can be located for impressing a franking mark thereon, by relative movement of the head and platen, wherein the printing head includes a retentive pad porous rubber stamp which is either impregnated with ink for life or has a reservoir and filler into which ink can be poured from time to time and is adapted to supply ink to the retentive pad.

2. A franking machine as claimed in Claim 1 wherein the inked for life pad comprises two layers of porous material one layer having large pores and the other, forming the printing surface, having much smaller pores.

3. A franking machine as claimed in Claim 1 wherein a separate reservoir is provided above the pad so that ink can flow down therefrom and the reservoir includes a filler by which additional ink can be supplied thereto to replenish the supply.

4. A franking machine as claimed in any of Claims 1 to 3 wherein the franking mark includes constant data and changeable data and an inked for life retentive pad porous rubber stamp is employed for the constant data and a reservoir supplied retentive pad porous rubber stamp is employed for the changeable data.

5. A franking machine as claimed in Claim 4 wherein the changeable data is contained on one or more endless rubber belts or around rubber tyred wheels and an inking reservoir is provided adjacent the belt or tyre so that ink is transferred to the latter as the belt or tyred-wheel is rotated to select different characters or groups of characters therearound for printing.

6. A franking machine as claimed in Claim 5 wherein the rubber belts are relatively thin so as to allow them to pass around driving wheels and the like since the regular inking of the belt will ensure that there is always sufficient ink on the surface thereof to provide for a good impression.

7. A franking machine as claimed in any of claims 4 to 6 wherein constant and changeable data bearing inked printing devices are contained in a single printing head of a printing machine and at least that part of the head containing the constant data printing device is movable relative to the remainder of the head to permit the device containing the constant data to be replaced to allow the constant data to be changed.

8. A franking machine as claimed in any of Claims 4 to 7 wherein constant and changeable data bearing inked printing devices are contained in a single printing head and at least a portion of the platen which aligns with the printing device containing the constant data is movable or removable, to give access to the device containing the constant data to allow the latter to be removed and replaced with another containing different constant data.

9. A frankirgmachine as claimed in Claim 1 in which the printing head contains devices for printing constant and changeable data onto packets and envelopes and which further includes a platen on which the packets and envelopes are located for franking, and wherein each of the printing devices comprises a self inking or inked-for- life printing device so that the printing head can be of simple construction and will contain few moving parts.

10. A franking machine when fitted with at least one porous pad rubber stamp printing element as claimed in any of claims 1 to 9 additional to at least one conventional printing element.

11. A franking machine as claimed in Claim 1 constructed, arranged and adapted to operate substantially as herein described with reference to and as illustrated in the accompanying drawings.