Abstract:
A film-aligning device applicable to an air cushion maker implements an eclectic heater to partially heat and soften a plastic film before the plastic film receives an inflating process and a softening process. When the plastic film is tending to proceed slantingly, the heated and soften plastic film performs a plastic deformation to realign the feeding stork of the plastic film.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Technical Field 
         [0002]    The present invention relates to air cushion makers, and more particularly, to a film-aligning device for aligning a plastic film during a feeding stork, so as to ensure smooth inflating and sealing processes. 
         [0003]    2. Description of Related Art 
         [0004]    For protecting packed objects from being damaged under accidental impact, buffer or cushion materials are generally used to fill void. As can be seen in  FIG. 1 , an air-bubble sheet made of plastic films is one of the most poplar cushion materials. A manufacture employs special equipments to produce such air-bubble sheet as a large piece, and a user can later cut or pucker the sheet at will to fill void in a packing case. However, the manufactured air-bubble sheet is space-consuming at transportation and storage due to its characters of being inflated and non-compressible. Thus, such air-bubble sheet is uneconomic and inconvenient in respect of transportation and storage. 
         [0005]    A desk-top air cushion maker has been therefore developed to remedy the aforementioned problem by providing an inflated and sealed air cushion, as depicted in  FIG. 2 . Such air cushion can be made in-site for instant use by the foregoing air cushion maker and is superior in convenience as well as economy. Nevertheless, a conventional desk-top air cushion maker typically suffer from slant film in the maker that tends to cause creases on the film and leads to defective inflating and sealing processes. 
       SUMMARY OF THE INVENTION 
       [0006]    One primary objective of the present invention is to provide a film-aligning device for automatically aligning and orienting a plastic film before the plastic film receives inflating and sealing processes in an air cushion maker. 
         [0007]    To achieve this and other objectives of the present invention, the film-aligning device comprises a plastic film roll rotatably mounted on a base of a desk-top air cushion maker, a plurality of film-pulling roller sets, a heater settled on the base. The heater provides a heating temperature ranging from 55 to 60 Centigrade degrees. The heater is positioned between the plastic film roll and the film-pulling roller sets that continuously draw out a plastic film from the plastic film roll. Thereby, the plastic film over the heater is heated and softened. In the event that the film is tending to become slant, two sides of the film receive different magnitudes of pulling force from the film-pulling roller set. At this time, the side receiving the relatively great pulling force becomes taut and the other side receiving the relatively small pulling force becomes loose, so that the film crossing over the heater performs plastic deformation that stops the uneven pulling force being transmitted toward the plastic film roll. As a result, the film between the plastic film roll and the heater is protected from receiving the uneven pulling force and kept aligned, thereby rectifying the film stroke from slanting and ensuring the following film proceeding straightly. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The invention as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to- the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: 
           [0009]      FIG. 1  is a perspective view of a conventional plastic air-bubble sheet; 
           [0010]      FIG. 2  is a perspective view of an air cushion made of a conventional desk-top air cushion maker; 
           [0011]      FIG. 3  is a perspective view of an air cushion maker according to the present invention, wherein a cover thereof is closed; 
           [0012]      FIG. 4  is another perspective view of the air cushion maker according to the present invention, wherein the cover thereof is open; 
           [0013]      FIG. 5  is a schematic drawing showing a plastic film passing over a heater according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0014]    While some preferred embodiments are provided hereinafter for illustrating the concept of the present invention as described above, it is to be understood that the components in these drawings are made for better explanation and need not to be made in scale. Besides, in the following description and the drawings, resemblances are indicated by the same numerals. 
         [0015]    Referring to  FIG. 3  for a perspective view of an air cushion maker according to the present invention. The air cushion maker primarily comprises a base  10  and a cover  12  that is liftably affixed to the base  10 , wherein the cover  12  is now lying on the base  10 . The cover  12  includes an arched canopy  13 , a button switch  14 , a plurality of function buttons  15  and a latch assembly  16  for holding the cover  12  with the base  10 . 
         [0016]    Another perspective view of the air cushion maker according to the present invention can be seen in  FIG. 4 and 5 , wherein the cover  12  is presently open. A film roll  17  to be inflated into an air cushion is mounted on a pair of roll supporters  20 . A plurality of rubber rollers  211 ,  212  are arranged-on the base  10  and the cover  12 , respectively, in the manner that when the cover  12  lies on the base  10 , each pair of the rubber rollers  211 ,  212  facing each other are vertically contact so as to form at least two film-pulling roller sets  21 . One said rubber roller  211  of one said film-pulling roller set  21  is rotate by a motor so as to drive the other rubber roller  212  contacting therewith. Hence, after being settled between the two contacting rubber rollers  211  and  212 , a plastic film  171  constituting the film roll  17  can be continuously pulling out from the film roll  17  as the rubber rollers keep rotating coordinately. Then the plastic film  171  passes an inflating device  22  and a sealing device  23  settled on the base  10  to receive inflating and sealing processes, thereby forming an air cushion as shown in  FIG. 2 . 
         [0017]    A heater  30  is provided on the base  10 , between the plastic film roll  17  and the film-pulling roller set  21 , and below a plane where the plastic film passes along. A pressing roller  31  is provided on the cover  12  adjacent to the plastic film roll  17  for contacting the heater  30  so as to press the plastic film  171  on a surface of the heater  30  for enhanced heating. The heater  30  is in a bar shape, and parallel to the film-pulling roller set  21 . It is to be noted that the heater  30  has a length long enough to heat the plastic film  171  for an entire width of the plastic film  171 , as shown in  FIG. 5 . 
         [0018]    The film-pulling roller set  21  draws out the plastic film  171  from the plastic film roll  17 . Thereby, the plastic film  171  over the heater  30  is heated and softened. In the event that the film is tending to become slant, two sides of the film  171  receive different magnitudes of pulling force from the film-pulling roller set. At this time, the side receiving the relatively great pulling force becomes taut and the other side receiving the relatively small pulling force becomes loose, so that the film  171  crossing over the heater  30  performs a plastic deformation that stops the uneven pulling force being transmitted toward the plastic film roll  17 . As a result, the film between the plastic film roll  17  and the heater  30  is protected from receiving the uneven pulling force and kept aligned, thereby ensuring the plastic film  171  continuously and straightly released from the plastic film roll  17 . Consequently, the heater  30  facilitates aligning the plastic film  171  and preventing the plastic film  171  from a slanting feeding stork. 
         [0019]    Although the particular embodiment of the invention has been described in detail for purposes of illustration, it will be understood by one of ordinary skill in the art that numerous variations will be possible to the disclosed embodiments without going outside the scope of the invention as disclosed in the claims.