Abstract:
An automatic screw feeder serves to automatically align a plurality screws laying in disarray and feed the aligned screws one by one to a power screwdriver so as to avoid screw clogging.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Technical Field 
         [0002]    The present relates to automatons and, more particularly, to an automatic screw feeder which serves to automatically align a plurality of screws and feed the aligned screws one by one to a power screwdriver. 
         [0003]    2. Description of Related Art 
         [0004]    Power-driven screwdrivers or pneumatic screwdrivers are tools facilitating rapidly screwing screws one the strength of electric power or pneumatic power. For the convenience of illustration, power-driven screwdrivers or pneumatic screwdrivers are hereinafter referred to as power screwdrivers. In one conventional application of the screwdriver, a user may manually hold and position a screw at a preset location and operate a power screwdriver to screw the screw tight. Such manual delivery of screws however retards the overall operation and nullifies the advantageous efficiency of the power screwdriver. Therefore, a screw feeder has been developed to align plural screws with heads of the screws upward and deliver the aligned screws to a feeding pipe for a power screwdriver to use. However, the conventional screw feeder tends to suffer from screw clogging and is not adaptive to screws smaller than a certain extent. 
       SUMMARY OF THE INVENTION 
       [0005]    One primary objective of the present invention is to provide an automatic screw feeder that serves to automatically align a plurality of screws laying in disarray and automatically deliver said screws one by one to a power screwdriver so as to prevent the feeder from screw clogging. Besides, since the screws are delivered one by one to the screwdriver, it is possible to count the amount of the screws used in one process by providing a counter to the automatic screw feeder. 
         [0006]    Another objective of the present invention is to provide an automatic screw feeder that is adaptive to screws of various dimensions, and is especially advantageous to fit very small screws. 
         [0007]    To achieve the aforesaid objectives, the automatic screw feeder of the present invention primarily comprises a feeding device, a distribution board and a rail. The feeding device has a sliding block that is able to linearly reciprocate. The distributing board is able to linearly reciprocate between a screw receiving position and a screw delivering position. The distributing board receives one screw at the screw receiving position, and then moves to the screw delivering position to make the sliding block abut against an immovable seat so that the screw is pushed into a blowing vent formed between the sliding block and the immovable seat by the sliding block and in turn falls into a feeding pipe. Then, when a high-pressure air is introduced into the feeding pipe, the screw is pushed to advance along the feeding pipe and delivered to a power screwdriver. 
         [0008]    Thereupon, the present invention enables delivering the screws one by one to the screwdriver with a predetermined time interval. Besides, it is possible in the present invention to use the rail and distribution board  30  of dimensions fitting specifications of the desired screws. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    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: 
           [0010]      FIG. 1  is a perspective view of an automatic screw feeder of the present invention; 
           [0011]      FIG. 2  is another perspective view of the automatic screw feeder of the present invention, wherein a distribution board is moved to receive a screw; 
           [0012]      FIG. 3  is another perspective view of the automatic screw feeder of the present invention, wherein the distribution board returns and the screw received thereby is delivered to a feeding device; 
           [0013]      FIG. 4  is another perspective view of the automatic screw feeder of the present invention, wherein a sliding block pushes the screw at the feeding device into a feeding pipe; 
           [0014]      FIG. 5  is a top view of the automatic screw feeder of the present invention; 
           [0015]      FIG. 6  is another top view of the automatic screw feeder of the present invention, wherein the distribution board is moved to receive a screw; 
           [0016]      FIG. 7  is another top view of the automatic screw feeder of the present invention, wherein the distribution board returns and the screw received thereby is delivered to the feeding device; and 
           [0017]      FIG. 8  is another top view of the automatic screw feeder of the present invention, wherein the sliding block pushes the screw at the feeding device into the feeding pipe. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    While a preferred embodiment is provided herein 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. 
         [0019]    Referring to  FIGS. 1 and 5 , an automatic screw feeder of the present invention comprises a feeding device  10 , a feeding pipe  20 , a distribution board  30 , and a rail  40 . 
         [0020]    The feeding device  10  includes an immovable seat  11  and a sliding block  12 . The immovable seat  11  consistently stands at a predetermined position while the sliding block  12  is able to linearly reciprocate with respect to the immovable seat  11  along a direction described by Arrow A in the drawings so as to approach or leave the immovable seat  11 . The immovable seat  11  and the sliding block  12  jointly define a blowing vent  13  at contacting surfaces therebetween. In the present embodiment, the sliding block  12  is driven by an extendable shaft  51  of a feeding cylinder  50  to perform a linear reciprocation. 
         [0021]    The feeding pipe  20  is connected to the immovable seat  11  and has an upper opening communicated with the blowing vent  13 . 
         [0022]    The distribution board  30  is configured to be perpendicular to the feeding device  10  and is capable to perform a linear reciprocation with respect to the sliding block  12  between a receiving position and a feeding position, as indicated by Arrow B. The distribution board  30  has one lateral  31  formed with a receiving recess  32  (shown in  FIGS. 2 and 6 ), whose upped end and lower end open to a top and a bottom of the distribution board  30 , respectively. When the distribution board  30  is at its receiving position, the receiving recess  32  receives one screw  33  and when the distribution board  30  is at its feeding position, the screw at the recess  32  falls into the feeding pipe  20 . The screw  33  is a known one having an expanded screw head and a screw body. The screw body of the screw  33  is received in the receiving recess  32  while the expanded screw head of the screw  33  is propped by the top of the distribution board  30  surrounding the receiving recess  32 . In the present embodiment, a distribution cylinder  60  has its extendable shaft  61  driving a driven board  62  so as to move the distribution board  30  fastened to the driven board  62 . 
         [0023]    The rail  40  allows a plurality of screws  33  aligned therein in the manner that the screw bodies of the screws  33  are received in a groove  41  of the rail  40  while the screw heads of the screws  33  are propped by a top of the rail  40 . A depressor  42  is set along the top of the rail  40  and separated from the top of the rail  40  by a predetermined distance so that the depressor  42  contacts tops of the screws  33  in the rail  40  to level the screws. Two ends of the rail  40  are defined as an inlet end  43  and an outlet end  44 , respectively, while the rail  40  tilts with the inlet end  43  standing higher than the outlet end  44  that contacts the lateral  31  of the distribution board  30  where the receiving recess  32  is formed. 
         [0024]    As can be seen in  FIGS. 2 and 6 , when the distribution board  30  leaves the feeding device  10  along a direction indicated by Arrow B 1  to a preset position, the headmost screw  33  at the outlet end  44  of the rail  40  slides into the receiving recess  32  of the distribution board  30 . Meanwhile, the sliding block  12  leaves the immovable seat  11  along a direction indicated by Arrow Al. 
         [0025]    Referring to  FIGS. 3 and 7 , the distribution board  30  moves along a direction indicated by Arrow B 2  to meet the feeding device  10  so that the receiving recess  32  and the screw  33  correspond to the upper opening of the feeding pipe  20 . Then the lateral  31  of the distribution board  30  abuts against the outlet end  44  of the rail  40  to uphold the screws  33  in the rail  40  from falling. 
         [0026]    Reference is now made to  FIGS. 4 and 8 . The sliding block now moves along a direction indicated by Arrow A 2  to meet the feeding device  10  and pushes the screw  33  to make the screw  33  in turn fall into the feeding pipe  20 . When the immovable seat  11  and the sliding block  12  are completely combined, a blowing unit can be implemented to give a high-pressure air to the blowing vent  13  so that the screw  33  is pushed to advance along the feeding pipe  20  to a power screwdriver (not shown). 
         [0027]    Through the previous description, it is learned that each time of said reciprocation of the distribution board  30  merely allows one screw to be received and delivered to the feeding device, so as to deliver the screws one by one to the screwdriver with a predetermined time interval. The rail  44  aligns and levels the screws in advance so that the screw can slide into the receiving recess  32  of the distribution board  30  one by one. According to specifications of the desired screws, the rail  40 , distribution board  30  and feeding device  10  can be properly designed or replaced, thereby allowing the present invention to be used with screws of various dimensions. The present invention is particularly advantageous for being adaptive to very small screws. 
         [0028]    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 embodiment without going outside the scope of the invention as disclosed in the claims.