Abstract:
An electric press with dust generation preventing device, especially used in a clean spaced room, is disclosed, wherein the electric press has the essential elements including a pressing ram, an electric drive motor and a transmission provided between the drive motor and the pressing ram and transmitting the driving force of the drive motor to the pressing ram to reciprocatingly move the ram relative to a work to be pressingly processed, the electric press substantially comprises a casing structured airtight for covering the essential elements, an pipe elongated and having one end thereof being located within the casing and the opposite end being located in an open air outside of the clean spaced room and an air absorbing means provided in connection with said pipe and operated to cause the air in the casing to flow through said pipe out into the open air outside of the clean spaced room.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to an electric press and more particularly relates to an electric press provided with a device for preventing the electric press from generating dusts while the electric press is operated especially in a clean spaced factory and/or in a product studying and researching room. 
     2. Prior Art 
     The precision instruments and electronic parts are generally protected from dusts while these instruments and parts are assembled and/or manufactured so as to avoid the risk that the dusts will come into the instruments and the parts and deteriorate the quality of the same. Under the circumstances, many factories have a clean spaced room, or the factories themselves are made clean spaced to protect such instruments and parts from the dusts. 
     In the clean spaced room, the workers are generally forced to take on the working clothes which will not generate dusts. In this connection, the machine tools and testers which are used in the clean spaced room are required to have a function for preventing the dusts from being generated. The dust generation preventing function mentioned herein is the function which will prevent the dusts which may be generated from the vibrations, impacts, friction, etc. of machines and which may come into the products. 
     Generally, a small sized machine tool including a small sized machine robot has a casing covering the essential parts thereof. The casing is generally composed of a plurality of parts which are closely connected to each other, and generally has slight gaps or openings formed between the connected parts. Such gaps or openings may be neglected when the machine tool is used at a place where the problem of dusts is not a significant matter. 
     However such a machine tool is not suitable to be used in the clean spaced room where the above mentioned precision instruments and/or electronic parts are assembled or manufactured, because the gaps or openings of the casing will allow the dusts to come out of the casing into the clean space of the room and come into the products, the dusts being generated due to the impacts and vibrations which may be caused during the operations of the machine tool. 
     More particularly the dusts include the pulverized fine particles of metal, synthetic resin, gum, etc. which may be generated due to the abrasions of the working parts of the machine tool including the machine drive motor, the-mechanisms driven by the machine drive motor and the transmission belts provided between the machine drive motor and the driven mechanisms and between the driven mechanisms. 
     It is therefore required that the machine tool which is used in the clean spaced room has a device or function for preventing the dusts from being generated while the machine tool is operated. The machine tools having such dust generation preventing device or function have been known. However, the dust generation preventing device or the function part is totally big sized and complicated in structure. 
     Moreover, the casing of such machine tools has the slits formed thereat for air-cooling the machine drive motor. Such slits will easily allow the dusts to flow out of the casing. Further, the motor cooling fan will additionally increase the amount of dusts flowing out of the casing. 
     The invention has been provided to eliminate the defects and disadvantages of the prior art. It is therefore a principle object of the invention to provide an electric press with a dust generation preventing device which is simple in structure and effective in function and is moreover adapted to use in a clean spaced room. 
     It is another object of the invention to provide an air tight casing covering the essential parts of the machine tool. 
     Further it is another object of the invention to provide a pipe extending from the inside of the casing to the outside of the clean spaced room for blowing out the dusts generated in the casing into the outer air through the pipe. 
     SUMMARY OF THE INVENTION 
     In short, the present invention substantially relates to an electric press with a dust generation preventing device used in a clean spaced room and having the essential elements including a work pressing means including a ram, a drive means including an electric drive motor and a transmission means provided between the drive means and the work pressing means and transmitting the driving force of the drive means to the work pressing means reciprocatingly move the ram relative to a work to be pressingly processed, the electric press substantially comprising a casing structured airtight for covering the essential elements, a pipe elongated and having one end of thereof being located within the casing and the opposite end being located in an open air outside of the clean spaced room and an air absorbing means provided in connection with said pipe and operated to cause the air in the casing to flow through said pipe out into the open air outside of the clean spaced room. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the electric press according to the invention; 
     FIG. 2 is a side elevational view of the electric press shown partly in vertical section to show the inner essential elements of the electric press; 
     FIG. 3 is a perspective view of the electric press showing the inside of the casing of the electric press where the essential press elements and the dust absorbing pipe are arranged according to the invention; 
     FIG.  4 (A) is a plan elevational view of the essential press elements and the dust absorbing pipe partly shown and partly cut out to show the dust absorbing pipe for absorbing the dusts; 
     FIG.  4 (B) is a side elevational view of the essential press elements and the dust absorbing pipe partly shown and partly cut out to show the pipe absorbing the dust 
     FIG. 5 is another perspective view of the electric press according to the invention; 
     FIG. 6 is a perspective view of the electric press showing a second embodiment of the invention; 
     FIG. 7 is a side elevational view of the electric press shown partly in vertical section to show the inner essential elements of the second embodiment of the invention; 
     FIG. 8 is a perspective view of a third embodiment of the invention having air cooling slits provided to the casing of the electric press; 
     FIG.  9 (A) is a perspective view of a movable group of air cooling slits and a fixed group of air cooling slits to be applied to the electric press; 
     FIG.  9 (B) is a side elevational view of the movable slits and the fixed slits shown in vertical section wherein the movable slits are moved with respect to the fixed slits to open the air cooling slits; 
     FIG.  9 (C) is a side elevational view of the movable slits and the fixed slits shown in vertical section wherein the movable slits are moved with respect to the fixed slits to close the air cooling slits; and 
     FIG. 10 is another embodiment of the cooling device shown in vertical section. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention will now be described in reference to the attached drawings. In reference to FIGS. 1 and 2, the electric press of the invention has an airtight casing A covering the upper essential parts of the electric press and a lower working bed  3 . The casing A is composed of a head  1  and a column  2  extending from the head  1  to the working bed  3  for supporting thereon a work to be pressed. 
     The head  1  has an operation board (though not shown) provided on the front side thereof. The joint between the head  1  and the column  2  is sealed to be substantially airtight. 
     The working bed  3  has a controller  4  provided on the front side thereof. The column  2  of the casing A has the lower end fixedly connected to the upper surface of the working bed  3  and sealed to be airtight. In any case, the casing A must be airtight even if the casing is composed of more than the head  1  and the column  2 . 
     In the casing A there are provided a drive part  5 , a transmission part  6 , a pressing part  7  and a control part  8  which are all movable with their own functions. More particularly, the drive part  5  includes an electric motor. The transmission part  6  is arranged between the drive part  5  and the pressing part  7  and includes pulleys  6   a  and a transmission belt  6   b  extended around the pulleys  6   a.    
     The pressing part  7  is substantially composed of a ram  7   a  and a ram driving member  7   b  which is operated to move the ram  7   a  vertically of a work (not shown) placed on the working bed  3  to be pressed. The ram driving member  7   b  is of a cylindrical structure in which an elongated threaded member is rotated with ball bearings to vertically move the ram  7   a  with a stroke S relative to a work placed on the working bed  3  to be pressed by the ram  7   a.    
     The ram  7   a  is axially covered with a vertically flexible dust boot  14 . The dust boot  14  has the upper end sealingly connected to the lower end of the head  1  of the casing A and has the lower end sealingly connected to the lower part of the ram  7   a  such that the dust boot  14  may be vertically flexible with the vertical movements of the ram  7   a , thereby to prevent the dusts from coming out of the casing A while the ram is vertically moved. 
     A dust absorbing pipe  10  is provided in the casing A. The dust absorbing pipe partly extends along a route adjacent to the moving vibration and/or impact generating elements including the drive part  5 , the transmission part  6  and the work pressing part  7 . 
     As shown in FIG. 3, the dust absorbing pipe  10  includes a dust guiding portion  10   a  and a dust absorbing portion  10   b  and is made of the materials including a metal such as a stainless steel and a synthetic resin such as silicon gum. 
     Particularly the dust absorbing portion  10   b  is extended along the entire route around and adjacent to the moving and vibration and/or impact generating elements including the drive part  5 , the transmission part  6  and the work pressing part  7 . 
     The dust absorbing portion  10   b  has a plurality of apertures or openings  10   b   1  formed thereat with a predetermined interval provided therebetween for the purpose of absorbing thereat the dusts as well as the heat which will be generated from the drive part  5 , the transmission part  6  and the work pressing part  7  and the control part  8  as shown in FIGS.  4 (A) and (B). The apertures  10   b   1  may be circular or oval. 
     The dust absorbing pipe  10  has one end, that is, the end of the dust guiding pipe  10   a , brought to an opening  11  provided at one side wall of the column  2  of the casing A where the dust absorbing pipe  10  is conductive with the outer air of the casing A. 
     A pressure adjusting valve  12  is provided on the casing A. The pressure adjusting valve  12  may be operated to adjust the atmospheric pressure which may be varied in the casing A due to the vertical motion of the ram  7 . The pressure adjusting valve  12  may be a valve to be manually operated or to be electromagnetically operated with a pressure sensor. 
     As shown in FIG. 2, the electric press of the invention has an outer pipe  15  extending therefrom to the outside of the clean spaced room for guiding the absorbed dusts out into the atmosphere outside of the clean spaced room where the electric press is located. The outer pipe  15  has one end connected to the end of the dust absorbing pipe  10  at the opening  11  of the casing A and has the opposite end connected to a blower  16  located outside of the clean spaced room. The blower  16  located outside of the clean spaced room. The blower  16  is operated to suck the dust generated within the casing A into the dust absorbing pipe  10 , and blow the dust through the outer pipe  15  outside of the clean spaced room. A flow meter  17  may be provided to the outer pipe  15 . 
     FIGS. 6 and 7 show a second embodiment of the invention, wherein the electric press has no dust absorbing pipe  10 , which is provided in the first embodiment of the invention. According to the second embodiment, the outer pipe  15  has one end connected to the opening  11  of the casing A and has the opposite end connected to the blower  16  located outside of the clean spaced room in the same manner as in the first embodiment. In the second embodiment, the dusts generated in the casing A are absorbed at the opening  11  of the casing A and the absorbed dusts are blown out of the clean spaced room through the outer pipe  15  out into the outer atmosphere by the blower  16 . 
     FIG. 8 shows a third embodiment of the invention, wherein the electric press has cooling slits  13  provided to the head  1  of the casing A such that the electric press may be functionally effective when it is used at a place other than the clean spaced room as well. 
     When the electric press is used at a place other than the clean spaced room, the cooling slits  13  are opened to allow the outer air to flow into the casing A, thereby to cool down the essential elements generating heat in the casing A including the drive part  5 , the work pressing part  7  and the control part  8 . 
     The cooling slits  13  may be optionally closed to render the casing A airtight. More particularly the cooling slits  13  are composed of a fixed group of slits collectively denoted by the reference numeral  13   a  and comprising a plurality of slits  13   a   1  and a group of slits  13   b   1  provided to a plate  13   b  as shown in FIG.  9 (A). 
     As shown in FIGS.  8  and  9 (A), the fixed group of slits  13   a  may be provided optionally to the top and side walls of the casing A in a manner that the respective slits  13   a   1  are arranged in parallel with each other with a predetermined interval provided therebetween. 
     The plate  13   b  has a plurality of slits  13   b   1  provided thereto in a manner that the respective slits  13   b   1  are arranged in parallel with each other with a predetermined interval provided therebetween. The plate is movably attached to the casing A in reference to the fixed group of slits  13   a.    
     For the purpose of movably attaching the plate  13   b  to the casing A, an optional proper number of threaded holes  13   c   1  are provided to the casing A with reference to the fixed group of slits  13   a . On the other hand, the same number of elongated openings  13   c   2  are provided to the plate  13   b  with reference to the slits  13   b   1 . The plate  13   b  may be fixedly attached to the casing A by means of screws  13   d  which are inserted into the elongated openings  13   c   2  of the plate  13   b  respectively and threaded into the respective threaded holes  13   c   1  of the casing A. 
     When the screws  13   d  are loosened, the plate  13   b  may be moved in the longitudinal directions of the elongated openings  13   c   2  to the place where the slits  13   b   1  are vertically in alignment with the slits  13   a   1  as shown in FIG.  9 (B) and to the place where the slits  13   b   1  are displaced from the slits  13   a   1  to close the cooling slits  13 , thereby to render the casing A airtight as shown in FIG.  9 (C). 
     As shown in FIG. 10, the plate  13   b  may be replaced by a plate  13   e  having no slits provided thereto as shown in FIG.  10 . The plate  13   e  is fixedly attached to the casing A by means of the screws  13   d  to close the slits  13   a   1  to render the casing A airtight. With the screw  23   d  being unscrewed, the plate  13   e  may be removed from the casing A to allow the outer air to flow into the casing A through the slits  13   a   1 . 
     Although the invention has been described in conjunction with the specific embodiments thereof, it is to be understood that many variations and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.