Paper roll fixing device of printer

A paper roll fixing device of a printer includes a first supporting base, a second supporting base, a first fixing member and a second fixing member. The first fixing member comprises a rotatable first fixing slab. The second fixing member comprises a rotatable second fixing slab. When the first fixing slab and the first fixing slab are pushed by a paper roll, the first fixing slab and the first fixing slab are rotated to the position without stopping the paper roll from entering or leaving the space between the first supporting base and the second supporting base. As a consequently, the paper roll can be smoothly introduced into or removed from the paper roll fixing device. By the paper roll fixing device, the paper roll can be introduced into or removed from the paper roll fixing device with a single hand or in a single step.

CROSS-REFERENCES TO RELATED APPLICATIONS

This non-provisional application claims priority under 35 U.S.C. §119(a) to Patent Application No(s). 100101400 filed in Taiwan, R.O.C. on Jan. 14, 2011, the entire contents of which are hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to a paper roll fixing device, and more particularly to a paper roll fixing device of a printer.

BACKGROUND OF THE INVENTION

In the markets, many conventional printers (e.g. label printers) use paper rolls as print media. The label printer usually has a paper roll fixing device for fixing the paper roll within the label printer. After the paper roll is fixed within the label printer, the task of printing the label paper can be performed by the printing mechanism of the label printer.

FIG. 1Ais a schematic perspective view illustrating a label printer according to the prior art. The label printer1is disclosed in U.S. Pat. No. 6,431,492. As shown inFIG. 1A, a paper roll fixing device11is installed within the label printer1. The paper roll fixing device11comprises a first supporting base12and a second supporting base13. Please refer toFIG. 1BandFIG. 1C.FIG. 1Bschematically illustrates the first supporting base12, a first movable track14and a second movable track15of the paper roll fixing device11.FIG. 1Cschematically illustrates the second supporting base13, the first movable track14, the second movable track15and the gear16of the paper roll fixing device11. The first supporting base12comprises a supporting protrusion part12a. The second supporting base13comprises a supporting protrusion part13a. The paper roll fixing device11further comprises the first movable track14, the second movable track15and the gear16. The first movable track14and the second movable track15are parallel with each other. An end14aof the first movable track14is connected with the first supporting base12. An end15aof the second movable track15is connected with the second supporting base13. The gear16is clamped between the first movable track14and the second movable track15, and engaged with the first movable track14and the second movable track15. Through the gear16, the first movable track14and the second movable track15may be linearly moved back and forth in a reciprocating manner. In such way, the distance between the first supporting base12and the second supporting base13is adjustable.

For installing a paper roll within the label printer1, a first end of the paper roll is firstly fixed on the first supporting base12. That is, the first end of the paper roll is fixed by the supporting protrusion part12a. Then, the second supporting base13is moved toward the first supporting base12. During the process of moving the second supporting base13, the second movable track15that is connected with the second supporting base13and the first movable track14that is connected with the first supporting base12are linearly moved through the gear16. As a consequence, the first supporting base12and the second supporting base13approach each other. Until the second end of the paper roll is fixed by the supporting protrusion part13aof the second supporting base13, the paper roll is fixed within the paper roll.

For removing the paper roller from the internal portion of the label printer1, the first supporting base12or the second supporting base13needs to be pulled out. During the process of pulling out the first supporting base12or the second supporting base13, the first movable track14and the second movable track15are moved relative to each other through the gear16. As a consequence, the first supporting base12and the second supporting base13are distant from each other. Meanwhile, the both ends of the paper roll are no longer securely fixed by the supporting protrusion part12aof the first supporting base12and the supporting protrusion part13aof the second supporting base13, and thus the paper roll may be removed without difficulty.

From the above discussion, the paper roll can be fixed within the internal portion of the label printer1by the first supporting base12and the second supporting base13of the paper roll fixing device11.

However, the paper roll fixing device11of the label printer1still has some drawbacks. For introducing the paper roll into the internal portion of the label printer1, a first end of the paper roll is firstly held by one hand of the user and fixed on the first supporting base12, and then the distance between the first supporting base12and the second supporting base13is adjusted by the other hand of the user until the second end of the paper roll is fixed on the second supporting base13. Whereas, for removing the paper roll, the distance between the first supporting base12and the second supporting base13is adjusted; and until the both ends of the paper roll are no longer fixed on the first supporting base12and the second supporting base13, the paper roll is removed. In other way, since two hands or at least two steps are necessary to introduce the paper roll into the paper roll fixing device or remove the paper roll from the paper roll fixing device, the operations of the paper roll fixing device are inconvenient to the user.

Therefore, there is a need of providing an improved paper roll fixing device of a printer so as to obviate the drawbacks encountered from the prior art.

SUMMARY OF THE INVENTION

The present invention provides paper roll fixing device of a printer for allowing the user to introduce the paper roll into the paper roll fixing device or remove the paper roll from the paper roll fixing device with a single hand and in a single step.

In accordance with an aspect of the present invention, there is provided a paper roll fixing device of a printer for fixing a paper roll within the printer. The paper roll fixing device includes a first supporting base and a second supporting base. The first supporting base includes a first inner surface, a first outer surface and a first fixing member. The first fixing member includes a first fixing slab, a first shaft and a first elastic element. The first fixing slab further includes a first post. The first shaft and the first elastic element are installed on the first supporting base. The first fixing slab is pivotally connected with the first shaft. The first elastic element is connected with the first fixing slab, so that the first post of the first fixing slab is not protruded outside the first inner surface. The second supporting base includes a second inner surface, a second outer surface and a second fixing member. A space is defined between the first supporting base and the second supporting base for accommodating the paper roll. The second fixing member includes a second fixing slab, a second shaft and a second elastic element. The second fixing slab further includes a second post. The second shaft and the second elastic element are installed on the second supporting base. The second fixing slab is pivotally connected with the second shaft. The second elastic element is connected with the second fixing slab, so that the second post of the second fixing slab is not protruded outside the second inner surface.

In an embodiment, the first supporting base further includes a first position-confining recess in the first outer surface, and the second supporting base further includes a second position-confining recess in the second outer surface. The first elastic element is disposed within the first position-confining recess. The first shaft is arranged under the first elastic element. The second elastic element is disposed within the second position-confining recess. The second shaft is arranged under the second elastic element.

In an embodiment, the first post is arranged at a first end of the first fixing slab, a second end of the first fixing slab is protruded outside the first inner surface of the first supporting base, the second post is arranged at a first end of the second fixing slab, and a second end of the second fixing slab is protruded outside the second inner surface of the second supporting base.

In an embodiment, the first post and the second post have respective slant surfaces for guiding the paper roll to be introduced into or removed from the space between the first supporting base and the second supporting base.

In an embodiment, the first supporting base further includes a first through-hole and a first backing sheet. The second supporting base further includes a second through-hole and a second backing sheet. The first backing sheet is disposed within the first through-hole, and the second backing sheet is disposed within the second through-hole. The first backing sheet further includes a third post protruded outside the first inner surface of the first supporting base. The second backing sheet further includes a fourth post protruded outside the second inner surface of the second supporting base.

In an embodiment, each of the third post and the fourth post further includes two slant surfaces for guiding the paper roll to be introduced into or removed from the space between the first supporting base and the second supporting base.

In an embodiment, the first fixing slab is disposed over the first backing sheet, and the second fixing slab is disposed over the backing sheet. Moreover, the first backing sheet and the second backing sheet are made of flexible materials.

In an embodiment, the paper roll fixing device further includes a first movable track, a second movable track and a rotating wheel. The first movable track and the second movable track are parallel with each other. The rotating wheel is clamped between the first movable track and the second movable track and engaged with the first movable track and the second movable track. An end of the first movable track is connected with the first supporting base. An end of the second movable track is connected with the second supporting base. The first movable track and the second movable track are linearly moved back and forth in a reciprocating manner through the rotating wheel, so that a distance between the first supporting base and the second supporting base is adjustable.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides a paper roll fixing device of a printer (e.g. a label printer).

FIGS. 2A and 2Bare schematic exploded views illustrating a paper roll fixing device of a printer according to an embodiment of the present invention and taken along different viewpoints. The paper roll fixing device2comprises a first supporting base21, a second supporting base24, a first movable track27, a second movable track28and a rotating wheel29.

The first supporting base21comprises a first inner surface211, a first outer surface212, a first through-hole213, a first position-confining recess214, a first fixing member22and a first backing sheet23. The first position-confining recess214is formed in the first outer surface212. The first fixing member22comprises a first fixing slab221, a first shaft222and a first elastic element223. The first fixing slab221further comprises a first post221a. The first post221ahas a slant surface221ab. The first backing sheet23is made of a flexible material. In addition, the first backing sheet23comprises a third post231. The third post231has a first slant surface231aand a second slant surface231b.

The second supporting base24comprises a second inner surface241, a second outer surface242, a second through-hole243, a second position-confining recess244, a second fixing member25and a second backing sheet26. The second position-confining recess244is formed in the second outer surface242. The second fixing member25comprises a second fixing slab251, a second shaft252and a second elastic element253. The second fixing slab251further comprises a second post251a. The second post251ahas a slant surface251ab. The second backing sheet26is made of a flexible material. In addition, the second backing sheet26comprises a fourth post261. The fourth post261has a first slant surface261aand a second slant surface261b.

FIGS. 3A and 3Bare schematic assembled views illustrating a paper roll fixing device of a printer according to an embodiment of the present invention and taken along different viewpoints. Please refer toFIGS. 3A and 3B. The first elastic element223is disposed within the first position-confining recess214of the first supporting base21and penetrated through a first end221bof the first fixing slab221. The first shaft222is arranged under the first elastic element223, and penetrated through a middle portion of the first fixing slab221. The first backing sheet23is disposed within the first through-hole213, and arranged under the first fixing slab221. The third post231of the first backing sheet23is protruded from the first inner surface211of the first supporting base21. The second elastic element253is disposed within the second position-confining recess244of the second supporting base24and penetrated through a first end251bof the second fixing slab251. The second shaft252is arranged under the second elastic element2523, and penetrated through a middle portion of the second fixing slab251. The second backing sheet26is disposed within the second through-hole243, and arranged under the second fixing slab251. The fourth post261of the second backing sheet26is protruded from the second inner surface241of the second supporting base24.

Moreover, the first supporting base21is connected with an end of the first movable track27. The second supporting base24is connected with an end of the second movable track28. The first movable track27and the second movable track28are parallel with each other. The both sides of the rotating wheel29are clamped between the first movable track27and the second movable track28, and engaged with the first movable track27and the second movable track28. Through the rotating wheel29, the first movable track27and the second movable track28may be linearly moved back and forth in a reciprocating manner. In such way, the distance between the first supporting base27and the second supporting base28is adjustable.

Hereinafter, the operations of the paper roll fixing device according to the embodiment of the present invention will be illustrated with reference toFIGS. 4A and 4B.FIG. 4Ais a schematic cross-sectional view illustrating a paper roll fixing device of a printer according to an embodiment of the present invention, in which the paper roll has not been installed within the paper roll fixing device.FIG. 4Bis a schematic cross-sectional view illustrating a paper roll fixing device of a printer according to an embodiment of the present invention, in which the paper roll has been installed within the paper roll fixing device.

The paper roll31has a central channel31a. Before the paper roll31is installed within the paper roll fixing device2, due to a pulling force of the first elastic element223, the first end221bof the first fixing slab221is rotated toward the first outer surface212of the first supporting base21by using the first shaft222as a fulcrum. Under this circumstance, the first post221ais not protruded outside the first inner surface211, a second end221cof the first fixing slab221is protruded outside the first inner surface211, and the slant surface221ab of the first post221ais parallel with the first supporting base21. As a result, the paper roll31can be smoothly transported across the first post221a. Similarly, due to a pulling force of the second elastic element253, the first end251bof the second fixing slab251is rotated toward the second outer surface242of the second supporting base24by using the second shaft252as a fulcrum. Under this circumstance, the second post251ais not protruded outside the second inner surface241, a second end251cof the second fixing slab251is protruded outside the second inner surface241, and the slant surface251ab of the second post251ais parallel with the second supporting base24. As a result, the paper roll31can be smoothly transported across the second post251a.

During the process of introducing the paper roll31into the space between the first supporting base21and the second supporting base24, the second end221cof the first fixing slab221and the second end251cof the second fixing slab251are pushed by the both ends of the paper roll31, respectively. Under this circumstance, the second end221cof the first fixing slab221is rotated toward the first outer surface212of the first supporting base21by using the first shaft222as a fulcrum, and the second end251cof the second fixing slab251is rotated toward the second outer surface242of the second supporting base24by using the second shaft252as a fulcrum. As a result, the paper roll31can be smoothly advanced without being stopped. As the paper roll31is continuously moved downwardly, the third post231of the first backing sheet23and the fourth post261of the second backing sheet26are pressed by the both ends of the paper roll31. Under this circumstance, the third post231is moved toward the first outer surface212of the first supporting base21, the fourth post261is moved toward the second outer surface242of the second supporting base24, and the paper roll31can be smoothly transported through the region between the first slant surface231aof the third post231and the first slant surface261aof the fourth post231. After the paper roll31is completely introduced into the space between the first supporting base21and the second supporting base24, the first fixing slab221and the second fixing slab251are rotated to be parallel with the first supporting base21and the second supporting base24. Meanwhile, the first post221aof the first fixing slab221is protruded outside the first inner surface211of the first supporting base21, and the second post251aof the second fixing slab251is protruded outside the second inner surface2411of the second supporting base24. As a result, the first post221aand the second post251aare sustained against the both ends of the top portion of the central channel31aof the paper roll31. Since the pulling force is no longer exerted on the first backing sheet23and the second backing sheet26, the first backing sheet23and the second backing sheet26are returned to the original positions due to the toughness properties thereof. As a result, the third post231and the fourth post241are sustained against the both ends of the bottom portion of the central channel31aof the paper roll31. In this situation, the paper roll31is securely fixed between the first supporting base21and the second supporting base24.

For removing the paper roll31from the space between the first supporting base21and the second supporting base24, the paper roll31is moved upwardly, so that the third post231of the first backing sheet23and the fourth post241of the second backing sheet26are pushed upwardly by the both ends of the paper roll31. Under this circumstance, the third post231is moved toward the first outer surface212, the fourth post261is moved toward the second outer surface242, and the paper roll31can be smoothly transported through the region between the second slant surface231bof the third post231and the second slant surface261bof the fourth post231. At the same time, the second end221cof the first fixing slab221and the second end251cof the second fixing slab251are no longer pushed by the both ends of the paper roll31. Due to a restoring force of the first elastic element223, the first end221bof the first fixing slab221is rotated toward the first outer surface212of the first supporting base21by using the first shaft222as a fulcrum. Consequently, the first post221ais returned to the original position, and is no longer protruded outside the first inner surface211. Similarly, due to a restoring force of the second elastic element253, the first end251bof the second fixing slab251is rotated toward the second outer surface242of the second supporting base24by using the second shaft252as a fulcrum. Consequently, the second post251ais returned to the original position, and is no longer protruded outside the second inner surface241. Under this circumstance, the paper roll31can be removed upwardly. After the paper roll31is completely removed, the pulling force of the paper roll31is no longer exerted on the third post231and the fourth post261. Consequently, the third post231and the fourth post261are returned to the original positions due to the toughness properties thereof.

From the above description, by means of the first fixing member22, the first backing sheet23, the second fixing member25and second backing sheet26, the paper roll31can be securely fixed between the space between the first supporting base21and the second supporting base24during the paper roll31is placed on the paper roll fixing device2. Moreover, by moving the paper roll31upwardly, the paper roll31is no longer securely fixed between the space between the first supporting base21and the second supporting base24, so that the paper roll31can be smoothly removed. By using the paper roll fixing device of the present invention, the paper roll can be introduced into or removed from the paper roll fixing device with a single hand and in a single step. In such way, the process of replacing the paper roll is time-saving, and the convenience of using the paper roll fixing device is enhanced.