GB2493357A

GB2493357A - Printer having a lid movable between closed, intermediate and open positions

Info

Publication number: GB2493357A
Application number: GB1113251.1A
Authority: GB
Inventors: Ian Keith Evans; Andrew Hardy; Stephen John Elliott
Original assignee: Able Systems Ltd
Current assignee: Able Systems Ltd
Priority date: 2011-08-01
Filing date: 2011-08-01
Publication date: 2013-02-06
Anticipated expiration: 2031-08-01
Also published as: GB2493357B; GB201113251D0

Abstract

A printer has a housing 1 containing a print head 2 and defining a compartment 3 for receipt of a printing substrate. A lid 4 is moveable between a closed position (fig.4) in which the compartment 3 is substantially covered by the lid 4 and an open position (fig.6) in which the compartment 3 is uncovered so as to allow insertion or removal of the printing substrate or a carrier therefore. The lid 4 is pivotally movable with respect to the housing 1 about a pivot 28, which defines a first axis, between the closed position and an intermediate position (fig.5) that is between the open and closed positions. The lid 4 is connected to the housing by means of a hinge 22 that defines a second axis. The lid 4 is rotatable about the second axis between the intermediate position and the open position. The first axis is spaced from the second axis such that pivotal movement of the lid about the first axis causes relative movement between the second axis and one or other of the lid 4 or housing 1. In one embodiment the printer is a thermal printer in which the lid 4 for the compartment 3 supports a platen roller. In the closed position the platen roller is disposed proximate to the print head 2 and in the open position the platen roller is distal from the print head 2.

Description

A Printer The present invention relates to a printer and more particularly, but not exclusively, to a direct thermal printer. Such printers may be, for example, hand-held portable devices or integrated into a point of sale terminal.

Direct thermal printers comprise a print head having thermal elements that create an image on a substrate, such as paper, that is treated so as to be heat sensitive. A typical printer of this kind has a body that defines a paper compartment for receipt of a continuous roll of paper or labels and houses a print head over which the end of the paper roll is passed for printing. The paper is drawn off the roll and on to the print head by means of a motor-driven platen roller that presses the paper against the print head.

When the roll of paper has been consumed the user opens a cover of the paper compartment and loads a new roll of paper. In printers that have a fixed platen roller disposed in the printer body the user must thread the leading edge of a new roll between the platen roller and the print head so that it is gripped and may be fed "* * forward. This process requires manual dexterity and may be time-consuming. *

In a more recent development, the platen roller is held captive on the underside of the *.ee cover of the paper compartment. Thus when the cover is opened in order to load a new *:*s* 20 roll of paper the platen roller moves with the cover in a direction away from the printer body and in particular the print head. This allows the leading edge of the replacement * paper roll to be placed over the print head before the cover is then closed to trap the paper between platen roller and the print head.

The opening mechanism of the cover is not always easy to operate, particularly when the printers are small in size. Features such as protruding handles or levers have been moulded into the upper surface of the cover to facilitate the opening operation but these still require some degree of manual dexterity and may be undesirable in several other respects. For example, there may be a tendency for the lever or handle to break easily or for it to catch on the operator's clothing. Furthermore it may be considered undesirable from an aesthetic point of view.

It is one object of the present invention to obviate or mitigate the aforesaid disadvantages. It is also an object of the present invention to provide for an improved or alternative printer.

According to the present invention there is provided a printer comprising: a housing containing a print head and defining a compartment for receipt of a printing substrate; a lid for the compartment; the lid being moveable between a closed position in which the compartment is substantially covered by the lid and an open position in which the compartment is uncovered so as to allow insertion or removal of the printing substrate or a carrier for the printing substrate; at least one pivot about which the lid is pivotally movable with respect to the housing about a first axis between the closed position and an intermediate position that is between the open and closed positions; the lid being connected to the housing by means of a hinge the hinge defining a second axis; the lid being rotatable about the second axis between the intermediate position and the open position; wherein the first axis is spaced from the second axis such that pivotal movement of the lid about the first axis causes relative movement between the second axis and one or other of the lid or housing.

The arrangement allows easy manipulation of the lid between the open and closed * a * * positions. For example, it allows the user to push on the lid to one side of the first axis to effect pivoting movement to the intermediate position whereupon the lid can then be a... easily moved to the open position about the second axis. * a ". 20

The second axis may be fixed relative to the housing with the rid being movable relative to second axis. Alternatively the second axis may be fixed relative to the lid and is movable with the lid relative to housing. a

The printer may further comprise a detent for releasably retaining the lid in the c]osed position. The detent is preferably releasable as the lid moves from the closed to the intermediate position. The detent may be biased into a retaining position where it retains the lid in the closed position and may be deflectable out of the retaining position against the biasing force as the lid moves from the closed to the open position. It may be so deflectable as it moves from the closed to the intermediate position. This may be achieved by virtue of the detent being inherently resilient or by employing a separate biasing member. The detent may be provided at any suitable location such as, for example, on or in the housing, the print head, or the lid.

The detent may take any suitable form. In one embodiment it may be a spring-loaded catch which may be made, for example, from wire.

The hinge may comprise at least one shaft which defines the second axis and at least one guidance track defined in the lid or the housing for guiding movement of the shaft or movement of the lid relative to the shaft. For example, in one embodiment the shaft is an elongate spindle that extends across the housing and is received in guide tracks (on the lid or housing at each end). In another embodiment there may be provided a pair of short stub shafts fixed to one of the housing or the lid for receipt in corresponding guide tracks defined by the other of the housing or lid.

The at least one guidance track may take any suitable form but is preferably in the form of a slot defined in the housing or the lid.

At least one biasing member may be provided for biasing the lid from the intermediate * position to the open position. The (or each) biasing member may be any sort of resilient * . * member or spring such as for example a torsion spring that is disposed around the second axis. The torsion spring may have a first end that bears against the lid and a second end that bears against the housing.

* . . * * The lid preferably has a leading edge and a trailing edge. The first axis may be located between the leading edge and the trailing edge. The first axis may be located between * the leading edge and the second axis. * . * .*

The at least one pivot may be defined by at least one projection on the lid or the housing. The projection may define a point or a profiled surface. In one embodiment the at least one projection may comprise a rib defined on one of the lid or housing with an arcuate surface for contact with the other of the lid or housing.

The printer may be a thermal printer with a thermal print head.

There may be a platen roller supported by the lid. In the closed position of the lid the platen roller may be disposed proximate to the print head and in the open position of the lid the platen roller may be distal from the print head. The detent may act on the platen roller to retain the lid in the closed position. For example, it may act on a shaft of the platen roller or a collar provided on the platen roller shaft.

The printing substrate may be paper or any other suitable material. It may be n the form of labels which may or may not be supported on a backing substrate. The printing substrate may be wound into a roll and may be supported on a carrier in the form of a tube or the like. Alternatively the substrate may comprise discrete sheets that are supported in a carrier such as a cartridge.

A specific embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a perspective view of a printer according to one embodiment of the present invention, shown with a lid open; Figure 2 isa plan view of the printer of figure 1; Figure 3 is a plan view of the printer of figure 1 but with the lid shown in a closed position; Figure 4 is a sectioned view along line A-A of figure 3; * * Figure 5 is a sectioned view along line A-A of figure 3 but with a lid of the printer shown partially open; and "" 20 Figure 6 is a sectioned view along A-A of gure 3 but with the lid of the printer shown fully open. S... * . .

* Referring now to the drawings, the exemplary printer is a direct thermal printer having a * * . * housing 1 containing a print head unit 2 (shown only in dotted line in figures 4 to 6) and defining a paper compartment 3 for receipt of a roll of paper (not shown). A hinged lid 4 for closing the paper compartment 3 supports1 on its underside, a detachable platen roller 5.

In use, the platen roller 5 is designed to grip and draw paper from the roll and urge it against the print head unit 2.

In the exemplary embodiment, the platen roller 5 comprises a metal shaft 6 with a siiicone rubber sleeve 7 for gripping the paper and a gear wheel 8 fixed at one end.

Towards each end of the rollerS there is a plastics collar 9, 10 by which the shaft S is rotatably supported. The underside of the lid 4 has two integrally moulded support members 11 that are spaced apart by a distance slightly shorter than the width of the paper compartment 3. The support members 11 each define a pair of resilient jaws 12 that support a respective plastics collar 9, 10. At both ends of the shaft 6 outer portions of the plastics collars 9, 10 extend beyond the jaws 12. The gear wheel 8 is fixed to the shaft 6 immediately outboard of a first of the collars 9. At the opposite end the outer portion ba of the second plastics collar 10 has a larger diameter than the rest of the collar.

The print head unit 2 is a removable assembly that fits into a recess 13 adjacent to the paper compartment 3. It includes an array of print head thermal elements that extend across a significant width of the housing 1. The thermal elements are selectively activated by a control circuit 14 to apply heat to the paper and are flanked at each end by a U-shaped cradle 15 for receipt of the shaft 6 of the platen roller 5. Immediately outboard of the print head unit 2 at one end is a gear train 16 that is drivingly connected to an output shaft of a motor (not shown) disposed in the housing 1. The *... : motor and gear train are operable to drive the gear wheel 8 and platen roller 5 in * rotation. * **. * .

The print head unit 2 further includes a microswitch 17 and a wire spring catch 18. The microswitch 17 is designed to sense when the platen roller 5 is in place and the spring * catch 18 is designed to retain the rorler 5 in prace in the manner of a detent. The spring * catch 18 has an upper portion 18a that is biased into the path described by the platen * roller shaft 6 as the lid 4 moves from the open to the closed positions. *

The lid 4 has a front end 20 at which the platen roller 5 is mounted and a rear end 21 at which the hinge 22 is located. The hinge 22 is of the floating type so as to permit a small degree of movement of the lid 4 towards or away from the housing 1 other than by rotation More specifically, the hinge 22 comprises a pair of stub shafts 23 that are fixed to the housing 1 on each side and which are received in short guide slots 24 defined in depending lugs 25 at the rear of the lid 4. The stub shafts may be integrally formed with the housing or may be separate components that are fixed to the housing in any suitable fashion. This cam arrangement allows the slots 24 to travel over the fixed shafts 23 so as to raise or lower the rear end 21 of the lid 4. On an inside surface of each side wall of the housing 1, at a location approximately half-way between the front and rear ends 20. 21 of the lid 4, there is a fulcrum 26 provided by vertical rib 27 terminating in an upper arcuate surface 28. In the closed position and the partially open position the underside of the lid 4 abuts the arcuate surface 28 of the fulcrum 26 on both sides.

When the lid 4 is closed, the outer portions of the plastics collars 10 on the platen roller are received in the U-shaped cradles 15 and the gear wheel 8 on the end of the platen roller shaft 6 meshes with the gear train 16 in the housing 1 such that the rolier 5 may be driven in rotation by the motor.

In use, the lid 4 is opened by applying a force at its rear end 21 above the region of the hinge 22, as indicated by arrow 6 in figure 5. This causes the guide slats 24 in the tugs to ride over the stub shafts 23 such that the lid 4 pivots on the fulcrums 26 about a fixed pivot axis and, as a consequence, the front end 20 is raised to the partially open position shown in figure 5 This movement lifts the platen roller 5 upwardly out of the cradles 15 such that the spring catch 18 is deflected out of the way allowing the lid 4 to be opened further. Ribs 35 are provided on the upper surface towards rear end of the lid 4 as an indication to the user where the opening force should be applied. They may * : * also provide a degree of grip to assist in the opening process. e. .

" 20 Torsion springs 29 are provided around the stub shafts 23 to bias the lid to the fully * S S Se -open position shown in figure 6. A first end of each torsion spring 29 acts on the underside of the lid 4 and the other end bears against part of the housing 1. Thus once * . S *5 the lid 4 has moved to the partially open position in figure 5, the torsion springs 29 * S S * apply a force to bias the lid to the fully open position whee it is inclined at substantially 90° to its dosed position as shown in figures 1, 2 and 6. With the lid 4 in this position the empty tube on which the paper was carried is removed from the compartment 3 and a replacement roll of paper fitted.

In order to close the lid 4 the user simply pushes on the front end as indicated by' arrow C in figure 6. This serves to pivot the lid in a reverse movement to that described above such that it moves into the intermediate position shown in figure 5. Further application of the force as indicated by arrow D in figure 5 closes the lid. As the lid 4 moves into the closed position (shown in figure 4) the large diameter outer portion ba of the second collar 10 bears against the upper portion iSa of the spring catch 16 and deflects it out of its path so that the collar 10 can pass into the U-shaped cradle 15 whereupon the catch 18 resumes its original position and bears against the collar 10 so as to retain the roller 5 in place in the manner of a detent. At this point the collar 10 bears against a plunger of the m)croswitch 17 so as to signal electrically that the platen roller 5 is in the operative position for printing.

The printed paper emerges through a small clearance 30 between the front end 20 of the lid 4 and an adjacent part of the housing 1. A serrated strip 31 is provided on the housing at this location to allow printed paper to be torn from the rest of the roll.

The floating hinge arrangement allows the lid to move relative to the axis of rotation defined by the stubs shafts 23 of the hinge 22. The axis of rotation is thus fixed relative to the housing 1. In an alternative embodiment the stub shafts 23 may be fixed to the lid 4 and are slidable in slots defined in the housing 1. In this arrangement the axis of rotation is fixed relative to the lid but moves relative to the housing It is to be understood that the roll of paper may be in the form of labels with or without a * * . . * backing sheet. It will also be appreciated that any other suitable printing substrate may be used besides paper.

The printer may be, for example, a hand-held portable device or panel-mounted at the * * point of sale, It may be used in many applications such as, for example, labelling (bar codes or otherwise), vehicle parking restriction enforcement, sales transactions where * * * receipts are required and self-service such as petrol forecourts, ticket machines, cash * * ** dispensers etc. It will be appreciated that numerous modifications to the above described design may be made without departing from the scope of the invention as defined in the appended claims. For example, the catch for the roller may take any suitable form and indeed there may be more than one such catch provided. In addition, the fulcrum may be provided by any kind of protrusions. It may be provided on the lid and may bear against a surface defined by the housing. Moreover, the guide slots of the hinge may be replaced by any suitable form of guide track for guiding the travel of the lid.

Furthermore, the stub shafts may be replaced by any shaft-like component of any length. For example, the lid may be connected to the housing by means of an elongate spindle that is fixed to the lid and is received in corresponding slots or guide tracks

B

defined in the housing on each side. Alternatively the spindle may be fixed to the housing and the guide tracks defined by the lid.

It is to be understood that the present invention may have application to other types of printers besides a direct thermal printer. Moreover, the printing substrate may be provided in other forms besides being arranged on a roll. For example it may be arranged into discrete sheets that may be supported in a cartridge or by any other

suitable carrier.

The described and illustrated embodiments are to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and mod[fications that come within the scope of the inventions as defined in the claims are desired to be protected. It should be understood that while the use of words such as "preferable", "preferably", "preferred" or "more preferred" in the description suggest that a feature so described may be desirable, it may nevertheless not be necessary and embodiments lacking such a

S S

* feature may be contemplated as within the scope of the invention as defined in the appended claims. In relation to the claims, it is intended that when words such as "a," "an," "at least one," or "at least one portion" are used to preface a feature there is no " 20 intention to limit the craim to only one such feature unless specifically stated to the S.....

* contrary in the claim. When the language "at least a portion" and/or "a portion" is used the item can include a portion andIor the entire item unless specifically stated to the contrary. *. .:

Claims

<claim-text>CLAIMS1 A printer comprising: a housing containing a print head and defining a compartment for receipt of a printing substrate; a lid for the compartment; the lid being moveable between a closed position in which the compartment is substantially covered by the lid and an open position in which the compartment is uncovered so as to allow insertion or removal of the printing substrate or a carrier therefor; at least one pivot about which the lid is pivotally movable with respect to the housing about a first axis between the closed position and an intermediate position that is between the open and closed positions; the lid being connected to the housing by means of a hinge, the hinge defining a second axis; the lid being rotatable about the second axis between the intermediate position and the open position; * * wherein the first axis is spaced from the second axis such that pivotal Se S. movement of the lid about the first axis causes relative movement between the second axis and one or other of the lid or housing. S...</claim-text> <claim-text>
2. A printer according to claim 1, wherein the second axis is fixed relative to the housing and lid is movable relative to second axis.</claim-text> <claim-text>
3. A printer according to claim 1, wherein the second axis is fixed relative to the lid and is movable relative to housing.</claim-text> <claim-text>
4. A printer according to any one of claims 1 to 3, further comprising a detent for releasably retaining the lid in the closed position, the detent being releasable as the lid moves from the closed to the open position.</claim-text> <claim-text>
5. A printer according to claim 4, wherein the detent is biased into a retaining position where it retains the lid in the closed position and is deflectable out of the retaining position so as to release the lid as it moves from the closed to the open position.</claim-text> <claim-text>
6. A printer according to claim 5, wherein the detent is a spring-loaded catch.</claim-text> <claim-text>
7. A printer according to any preceding claim, wherein the hinge comprises at least one shaft and at reast one guide track defined in the lid or the housing.</claim-text> <claim-text>
8. A printer according to claim 7, wherein the at least one guide track is in the form of a slot.</claim-text> <claim-text>
9. A printer according to any preceding claim, further comprising at east one biasing member for biasing the lid from the intermediate position to the open position.</claim-text> <claim-text>
10. A printer according to claim 9, wherein the at least one biasing member comprises at least one torsion spring disposed around the second axis.</claim-text> <claim-text>
11. A printer according to any preceding claim, wherein the lid haè a leading edge and a trailing edge! the first axis being located between the leading edge and the trailing * * . * edge. *</claim-text> <claim-text>
12. A printer according to any preceding claim, wherein the first axis is located between * the leading edge and the second axis. * *</claim-text> <claim-text>
13. A printer according to any preceding claim, wherein the at least one pivot is defined byat least one projection on the lid or the housing * S.
14. A printer according to claim 13, wherein the at least one projection comprises a rib defined on one of the lid or housing with an arcuate surface for contact with the other of the lid or housing.
15. A printer according to any preceding claim, wherein the printer is a thermal printer having a thermal print head and in which a platen roller is supported by the lid, wherein in the closed position the platen roller is disposed proximate to the print head and in the open position the platen roller is distal from the print head.
16. A printer according to any preceding claim wherein the compartment is configured to receive a roll of printing substrate.</claim-text>