Abstract:
A caulking tool ( 20 ) comprises mechanisms ( 24, 25, 26, 27 ) for temporarily securing the tool to a filter plate and a pivotally operable caulking body ( 29, 30, 31 ) which urges a caulking rope into a groove in the filter plate so as to capture a part of the filter cloth therein. This secures the filter cloth to the filter plate.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a filter caulking tool. 
     Some types of filter apparatus, such as filter presses comprise a number of filter plates. Conventionally, both sides of the filter plate are covered with a filter cloth. A central feed hole is provided through the plate. This feed hole is unobstructed by the filter cloth. A connecting device passes through the feed hole connecting the two filter plates. One such arrangement is shown in GB 2088231. The filter cloths need to be secured to the periphery of the filter plates. In some presses a rubber seal is provided between adjacent plates and the cloths are caulked into a groove in the plate which is located just outside the filter area, but within the seal area. A tool is required to achieve this caulking. 
     Caulking is traditionally achieved by forcing a rope or cord into a groove containing a peripheral region of the filter cloth. This method is very slow and labour intensive in that two people are required for each caulking operation. One is required to hold the cloth in the right position and another is required to caulk the filter. The fact that a press plate will generally need to be removed from the press and laid flat to be caulked, and then turned over and laid flat to install the filter cloth on the other side, makes the known method even more slow and cumbersome, the plates usually being large and heavy. Filter cloths are also often easily damaged by the wedge or hammer. The known caulking method is also a common cause of injury to workers installing the filters, mainly to the band fingers or elbow or wrist ligaments since the rope must be tightly fitted to ensure that it stays in the groove when the filter cloth distorts due to high flow pressures. The fact that workers often have to kneel down to caulk the filters also results in potential back injuries or strains. 
     The present invention has been made from a consideration of these problems. 
     SUMMARY OF THE INVENTION 
     According to the present invention, there is provided a caulking tool comprising means for temporarily securing the tool to a filter apparatus and a pivotally operable caulking body for urging a retaining member into a groove in the filter apparatus so as to capture a part of a filter cloth therein and thus secure the filter cloth to the filter apparatus. 
     The above referenced apparatus may be used to successfully and speedily caulk a filter cloth to a filter press plate by a single operation with less physical exertion and with a much reduced risk of injury. The apparatus also usually facilitates a better fit of the cloth into the groove of a filter plate. 
     The means for securing the tool to the filter apparatus preferably comprises a clamp. The tool may be clamped into position on the plate by any standard technique, such as by one or more screw clamps. 
     The tool preferably comprises a guide body, such as a bar or rod, along which the lever operable caulking body travels in an axial direction parallel to the filter plate groove. The caulking tool preferably comprises a bracket which is connected to the guide body so as to facilitate travel along the guide body. Each end of the guide body is ideally secured to the filter plate, preferably at the plate ends. The ends of the guide body may be secured to parts which are held in an external clamp. This tool can be fixed onto the top, bottom sides or comers of any filter plate. This allows just one person to caulk a filter, with one hand operating the lever and the other hand free to hold the cloth in the correct position. 
     The caulking body preferably comprises a foot for engaging the retaining member and a handle, which acts as a lever for the foot. The lever preferably pivots about the guide body in a direction perpendicular to the axial direction of movement for the lever. As the lever is pulled towards the operator and away from the plate, in a direction perpendicular to the groove, the base section of the lever is urged toward the plate and into the groove, pressing in the rope and filter cloth. 
     A further advantage is that the tool may be mounted on a stand outside the press and revolve around the filter plate to follow the groove. Therefore, cloths may be fitted without removing the plate. 
     The rope or other retaining member being caulked may be loose on top of the cloth or temporarily bonded to it, for example, by sewing, adhesive or pins, or it may be sewn into a hem or false hem around filter cloth periphery. 
     The guide body may be of any length corresponding to the length of grooves normally found in press plates. The lever foot may be wedge-shaped or T-shaped. The lever, bracket and foot are ideally an integral part. Most of the lever preferably lies about the guide body so that less physical effort is needed to caulk the cloth effectively. 
     The components may comprise any material, although metal, such as steel, is preferred. 
     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
     In order that the present invention may be more readily understood, specific embodiments thereof will now be described by way of example only and with reference to the accompanying drawings in which: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevation of a typical filter press plate on which the caulking tool of the present invention may be used; 
     FIG. 2 is a perspective view of one caulking tool of the present invention; and 
     FIG. 3 is a plan view of a second caulking tool of the present invention. 
    
    
     DESCRIPTION OF THE INVENTION 
     Referring to FIG. 1, a filter plate  10  for a filter press has two main faces only one of which is illustrated. A rubber seal  11  is provided around the periphery of the filter plate  10 . An aperture  12  is provided though the centre of the filter plate  10 . A filter cloth is provided on each main face of the filter plate  10 . The two filter cloths, only one of which  13  is shown, are connected via a tubular barrel neck that extends through the aperture  12  in the filter plate. 
     A groove  14  is provided in each main face of the filter plate. The filter cloth  13  on that face of the filter plate lies over that groove. A caulking rope  15  is then placed over the cloth and groove in a position which is in register with the groove. The rope is then urged into the groove so as to capture the filter cloth  13  on that side of the filter plate. The rope  15  is urged into position by the caulking tools which are illustrated in FIGS. 1 and 2. 
     Referring to FIG. 2, a caulking tool  20  comprises a bar  21 , the ends of which are each secured to a flange  22 , 23 . Each flange  22 , 23  is secured to an open box section  24 , 25  which is operative to be received over a corner of the filter plate  10 . In use, the two box sections  24 , 25  are received over adjacent corners of the filter plate  10  and the apparatus is thus secured in place by spring-loaded locating screws  26 , 27  which are urged towards the filter plate  10 , the filter plate  10  being retained between the rear walls only one of which  28  is illustrated, of the box sections  24 , 25  and the end of the spring-loaded located screws  26 , 27 . 
     A short tube  29  is received over the bar  21  such that it can slide along the length of the bar  21 . A long rod  30  is secured to the short tube  29 , a short T-shaped rod  31  extending from the base of the long rod  30  substantially perpendicular thereto. The short T-shaped rod  31  may be pivoted about the bar  21  by securing the short tube  29  about the bar  21 . 
     In use the caulking tool is secured in position such that the end of the T-shaped rod  31  is in register with the caulking rope  15 . The end of the T-shaped rod  31  may be used to urge the caulking rope  15  into position by pulling on the end of the long handle  30  so as to pivot the T-shaped rod  31  towards the rope  15  and thus urge it into the groove  14 . Different parts of the caulking rope  15  may be urged into position by first moving the short tube  29  along the bar  21  and then appropriately moving the T-shaped rod  31  into position. 
     The apparatus of FIG. 2 is used to move the caulking rope  15  into position in the long sections  32  of the filter plate groove. The caulking rope  15  may be caulked into position in the short angled sections  33  by a similar apparatus as illustrated in FIG. 3 having corner box section  34 , 35  operative to bring the T-shaped rod  31  into register with these short sections  33 . 
     It is to be understood that the above described embodiments have been made by way of illustration only. Many modifications and variations are possible. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be recognized by one skilled in the art are intended to be included within the scope of the following claims.