Abstract:
A film-tape eraser with normally retracted dispensing head includes an upper case, a lower case, and a dispensing mechanism pivotally connected to and located in the lower case. The upper case is also pivotally connected to the lower case to shield an upper part of the latter, while the dispensing mechanism is partially exposed from a top of the upper case. A downward push at a top of the dispensing mechanism would sink the dispensing mechanism and bring the dispensing head to a position exposed from a lower front of the lower case. When the dispensing mechanism is released from the downward push, an elastic strip at the bottom of the dispensing mechanism springs the dispensing mechanism up and brings the dispensing head to a retracted position in the lower case.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a film-tape eraser, and more particularly to a film-tape eraser with normally retracted dispensing head. A downward push at a top of the eraser would sink a dispensing mechanism of the eraser and bring a dispensing head to a position projected from a lower front of the eraser for use. When the downward push is released, the dispensing mechanism is elastically lifted and the dispensing head is retracted into the eraser. 
     2. Description of the Prior Art 
     Most of the conventional film-tape erasers do not include a cap, and are therefore subject to a damaged or deformed dispensing head when the erasers are unexpectedly dropped or impacted. A damaged or deformed dispensing head fails to dispense an erasing film-tape smoothly and continuously, and possibly becomes completely useless. 
     Even if a film-tape eraser initially includes a cap to protect the dispensing head against undesired damage or deformation, the cap tends to be ignored or discarded soon because it causes inconveniences to a user who has to remove and replace the cap each time the eraser is used. 
     Taiwanese Patent Application No. 88213471 discloses a film-tape eraser that includes a main body having a dispensing opening, an upper side of which is provided with an engaging part for a cap to pivotally connect thereto. The cap may be easily closed onto the dispensing opening to isolate the film-tape from an external environment and be easily lifted to expose the film-tape for use. Since the cap is pivotally connected to the main body of the eraser, it is protected against separating from the main body and becoming lost. However, the cap must be lifted each time the eraser is to be used. And, in the case the eraser is unexpectedly dropped with the cap in the lifted position, it is possible the cap is damaged and separated from the main body due to collision with the ground. Thus, the pivotally connected cap does not provide an effective solution to protect the dispensing head of the film-tape eraser. 
     It is therefore tried by the inventor to develop a film-tape eraser having a dispensing head that is normally retracted into the eraser and could be extended from the eraser for use simply by downward pushing a top of the eraser, so that the film-tape eraser is always protected against a damaged or deformed dispensing head. 
     SUMMARY OF THE INVENTION 
     A primary object of the present invention is to provide a film-tape eraser with a normally retracted dispensing head. When a downward push is applied at a top of the eraser, the dispensing head is moved to expose from a lower front of the eraser for use, and when the downward push is released, the dispensing head automatically retracts into the eraser and is protected against damage due to any undesired drop of or impact against the eraser. 
     Another object of the present invention is to provide a film-tape eraser having a dispensing mechanism that may be elastically lifted from a lower case of the eraser for replacement of a new erasing film-tape. 
     To achieve the above and other objects, the film-tape eraser of the present invention mainly includes an upper case, a lower case, and a dispensing mechanism pivotally connected to and located in the lower case. The upper case is also pivotally connected to the lower case to shield an upper part of the latter. The lower case has a curved bottom that serves as a slide way, and the dispensing mechanism is provided at a bottom with a forward extended elastic strip that is movably pressed at a front free end against the slide way of the lower case to normally elastically pushes the dispensing mechanism upward to partially expose from a top of the upper case. 
     A downward push at a top of the dispensing mechanism would sink the dispensing mechanism and bring the dispensing head to a position exposed from a lower front of the lower case. When the dispensing mechanism is released from the downward push, the elastic strip at the bottom of the dispensing mechanism springs the dispensing mechanism up and brings the dispensing head to a retracted position in the lower case. 
     The upper case is provided at two sidewalls near lower rear portions thereof with two locking holes for normally engaging with two locking studs projected from two release button provided on two sidewalls of the lower case. When the release buttons are inward pushed to disengage the locking studs from the locking holes, the upper case together with the dispensing mechanism are sprung up by the elastic strip at the bottom of the dispensing mechanism to locate above the lower case. A user may then remove an erasing film-tape from the dispensing mechanism and replace it with a new one. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein 
     FIG. 1 is a front perspective view of a film-tape eraser according to a preferred embodiment of the present invention, wherein a dispensing head of the eraser is in a retracted position when the eraser is not in use; 
     FIG. 2 shows a dispensing mechanism of the film-tape eraser of FIG. 1 is elastically depressed to project the dispensing head from the eraser; 
     FIG. 3 is an exploded perspective view of the film-tape eraser of FIG. 1; 
     FIG. 4 is a sectioned side view of FIG. 1; 
     FIG. 5 is a front perspective view of a case of the dispensing mechanism of the present invention; 
     FIG. 6 is a sectioned side view of FIG. 2; 
     FIG. 7 is a sectioned front view of the film-tape eraser of the present invention; 
     FIG. 8 is a vertical sectional view of the present invention showing release buttons on two sides of a lower case of the eraser are inward pushed to disengage the lower case from an upper case; and 
     FIG. 9 is a sectioned side view showing the dispensing mechanism and the upper case of the film-tape eraser are pivotally lifted from the lower case. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Please refer to FIG. 1 that is a front perspective view of a film-tape eraser with normally retracted dispensing head according to a preferred embodiment of the present invention, and to FIG. 3 that is an exploded perspective view of the film-tape eraser of FIG.  1 . As shown, the film-tape eraser of the present invention includes an upper case  1 , a lower case  2 , a dispensing mechanism  3 , and an erasing film-tape  4  mounted on the dispensing mechanism  3 . 
     The upper case  1 , as viewed from a top thereof, is an n-shaped hollow member having a rear wall and two sidewalls  11 . Upper and lower edges of the two sidewalls  11  are designed into predetermined curves. The sidewalls  11  are provided near their respective lower rear portions with a row of holes, a first hole of which is a locking hole  111 ; and at their respective front inner ends with an inward projected pivot shaft  12 . Each of the pivot shafts  12  is further provided with an open-bottomed pivoting hole  121  defining a lower opening  122 . Moreover, the upper case  1  is provided at a top of the rear wall with a stopper  13  that extends toward an inner side of the hollow upper case  1 . 
     The lower case  2  is a hollow case having a curved bottom  24  serving as a slide way and two sidewalls  25  to define a space  23  therein. The lower case  2  has a profile close to an inverted right-angled triangle to provide a front opening  231  and a top opening  232 . A connecting part  21  extends across a joint of the front and the top opening  231 ,  232  to connect the two sidewalls  25 . Two lateral ends of the connecting part  21  are formed into two shaft rings  211 , each of which defines a shaft hole  212  for one of the pivot shafts  12  at the front inner ends of the upper case  1  to engage therewith, so that the upper case  1  is pivotally turnable relative to the lower case  2  to a lifted position to locate above and expose the lower case  2  or to a lowered position to shield an upper part of the lower case  2 . 
     The two sidewalls  25  of the lower case  2  are provided near their respective rear ends with a round release button  22 , which is integrally formed at a lower end with the sidewall  25  and bordered by a slit  222 . A locking stud  221  is outward projected from an upper half of each release button  22 . When the upper case  1  is turned to the lowered position to partially shield the lower case  2 , the locking studs  221  are forced to engage into the locking holes  221 ; and when the release buttons  22  are inward depressed, the locking studs  221  are disengaged from the locking holes  221 , allowing the upper case  1  to be turned to the lifted position. A window  26  may be provided on one of the sidewalls  25  near a front portion thereof for a user to observe the dispensing mechanism  3  moving in the lower case  2 . 
     Please refer to FIG. 5 that is a front perspective view of one of two side cases  31  forming a part of the dispensing mechanism  3 . The dispensing mechanism  3  includes a left and a right side case  31 . The two side cases  31  are provided at their respective upper fronts with two outward projected shafts  311  that are adapted to pivotally position in the pivoting holes  121  via the lower openings  122 , allowing the dispensing mechanism  3  to locate in the upper case  1  and the inner space  23  of the lower case  2 . When the two side cases  31  are assembled to each other, a dispensing opening  312  is left at a lower front of the assembled side cases  31 . A mounting channel  313  is provided behind the dispensing opening  312  for a dispensing head  314  to mount thereto. The dispensing head  314  is coated with a thin layer of Teflon that enables a smooth contact of the erasing film-tape  4  mounted on the dispensing mechanism  3  with the dispensing head  314  without becoming stuck or even broken due to any friction between the erasing film-tape  4  and the dispensing head  314 . 
     The side cases  31  are partially provided at a top with a plurality of antislip lines  317 , and at their respective inner sides at predetermined positions with inward projected front and rear mounting shafts  318 , onto which a driving tape reel  321  and a driven tape reel  322  forming a film-tape driving mechanism  32  are respectively mounted. One of the side cases  31  is provided below its upper front portion with a longitudinally extended guide strip  319 . Transverse ribs  319   a  are formed on a top surface of the guide strip  319 , so that the erasing film-tape  4  mounted on the driving and the driven tape reels  321 ,  322  and passing the dispensing head  314  is guided through tops of the transverse ribs  319   a  to substantially float over the guide strip  319 , enabling stable and smooth dispensing of the erasing film-tape  4 . 
     The side cases  31  are also provided at their respective lower portions with a forward extended and inward projected elastic strip  315  having a predetermined curved configuration. Each of the elastic strips  315  has a front section that is not connected at an inner edge to an inner surface of the side case  31 , enabling the elastic strips  315  to have sufficient elastic tension. Meanwhile, the side cases  31  are provided at rear ends with rearward projected stoppers  316 . 
     Please refer to FIG. 4 that is an assembled sectioned side view of the film-tape eraser of the present invention. When the dispensing mechanism  3  is mounted in the lower case  2 , the elastic strips  315  normally extend their free ends downward to elastically press against the slide way  24  and thereby force the dispensing mechanism  3  to pivotally turn about the shafts  311  to lift a rear portion of the dispensing mechanism  3  until the stoppers  316  at the rear end of the assembled side cases  31  abut against the stopper  13  at the upper rear end of the upper case  1 , so that the dispensing mechanism  3  is held in the lower case  2 . With the dispensing mechanism  3  held in this lifted position, the dispensing head  314  is in a retracted position to locate behind the dispensing opening  231  without exposing from the lower case  2  and is therefore protected from damage in case of unexpected dropping of the whole film-tape eraser. 
     Please refer to FIGS. 2 and 6. When a user downward pushes the dispensing mechanism  3  at the antislip lines  317 , the elastic strips  315  are compressed to slide their free ends forward along the slide way  24 , allowing the whole dispensing mechanism  3  to sink in the lower case  2 . At this point, the dispensing head  314  is brought to a position projected from the dispensing opening  231  for the user to dispense a length of the erasing film-tape  4 . After the erasing, the user needs only to release the downward push from the antislip lines  317 , the elastic tension of the compressed elastic strips  315  immediately springs the whole dispensing mechanism  3  upward until the stoppers  316  abut against the stopper  13  again. At this point, the dispensing head  314  is brought back to the retracted position in the lower case  2  behind the dispensing opening  231 . 
     FIG. 7 is a sectioned front view of the film-tape eraser of the present invention in a normal condition. When a user wants to replace an old erasing film-tape  4  with a new one, he or she needs only to push the two release buttons  22  inward, as indicated by the arrows in FIG. 8, to disengage the locking studs  221  from the locking holes  111  and thereby release the upper case  1  from the lower case  2 . At this point, the elastic strips  315  in the lower case  2  pressed against the slide way  24  are no longer subjected to any downward force from the upper case  1 , and the elastic tension of the elastic strips  315  immediately springs the whole dispensing mechanism  3  and the upper case  1  up at the same time. The pivot shafts  12  of the upper case  1  are turned to orient the lower openings  122  of the pivoting holes  121  upward, and the user may easily remove the dispensing mechanism  3  from the upper case  1  by disengaging the projected shafts  311  from the pivoting holes  121 , and then use a new erasing tape  4  to replace the old one. 
     The present invention has been described with a preferred embodiment thereof and it is understood that many changes and modifications in the described embodiment can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims.