Abstract:
A filter plate assembly [ 1 ] comprises a filter plate [ 100 ] having a recess [ 102 ], a radially-inwardly extending shelf portion [ 108 ] having a seat surface [ 101 ], and a feed eye aperture [ 110 ] extending through the shelf portion. An adapter ring [ 170 ] is placed within said recess [ 102 ]. The adapter ring [ 170 ] has a flange [ 172 ] and a barrel [ 179 ] extending from the flange [ 172 ]. The barrel [ 179 ] has an inner wall [ 180 ] and an outer wall [ 182 ], and is positioned within said aperture [ 110 ] such that the outer wall [ 182 ] of the barrel [ 179 ] is in close proximity with said aperture [ 110 ]. The flange [ 172 ] comprises an inner surface [ 173 ] which abuts the seat surface [ 101 ]. The filter plate assembly [ 1 ] further comprises a filter cloth assembly [ 160 ] comprising a filter cloth [ 168 ] having an aperture [ 168 B], and a grommet [ 168 A] fitted within the filter cloth aperture [ 168 B]. The grommet [ 168 A] is configured to align with the adapter ring [ 170 ], and comprises a collar [ 167 ] having an inner surface [ 167 A] which is bonded or mechanically attached to a first side [ 188 ] of the filter cloth [ 168 ]. A second side [ 189 ] of the filter cloth [ 168 ] abuts a sealing surface [ 185 ] of the adapter ring [ 170].

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This invention relates to filtration processes and equipment, and more particularly to filter presses, such as those used in slurry dewatering processes during minerals processing. 
         [0002]    Filter presses generally comprise a horizontally-arranged stack of vertically extending filter plates which are separated by a small space when the filter press stack is fully opened for cake discharge. Each filter plate comprises respective filter cloths on its opposing sides. In order to facilitate installation or removal of the filter cloths, it is necessary to lift the very heavy and sizeable filter plate assemblies and in some instances, completely extract them from the horizontally-arranged stack to gain access to the securing mechanisms which join the filter cloth to the filter plate. An example of such a filter plate assembly is shown in U.S. Pat. No. 5,851,387, which is incorporated herein by reference. 
         [0003]      FIGS. 1 and 2  illustrate respective front plan and isometric cross-sectional views of one example of a conventional filter plate assembly  9 , and conventional feed eye assembly  940 , which require complete extraction from a filter press during filter cloth  968  replacement. Conventional filter plate assembly  9  comprises a first filter plate  100  defined by a base portion  104  having standoffs  120 , peripheral walls  130 , and a shelf portion  108 . The shelf portion  108  is generally composed of a seat surface  101 , a recess  102 , a tapered surface  103 , and a feed eye aperture  110 . Chamfers  112  surround the feed eye aperture  110 , and a plurality of bores  106  are provided within the shelf portion  108 . 
         [0004]    The conventional filter plate assembly  9  further comprises a conventional feed eye assembly  940 . The conventional feed eye assembly  940  comprises, on one side, a filter cloth  968  having an aperture  968 B therein, and a separate retaining ring  990  having a radial projection  998  and a ring protrusion  999  extending therefrom, which is configured to be received within the aperture  968 B of filter cloth  968 . Retaining ring  990  comprises a ring protrusion end  991 , a ring protrusion outer wall  994 , a ring protrusion inner wall  995 , a shelf  996 , an inner surface  993 , and one or more head clearance holes  992 . A backer plate ring  975  having one or more shaft clearance holes  997  may be positioned within the retaining ring  990 . 
         [0005]    The conventional feed eye assembly  940  comprises, on an opposite side, a holding ring  970  comprising a radial projection  971  and a barrel  979 , extending therefrom, which is configured to be received within the aperture  968 B of a filter cloth  968 . The holding ring  970  further comprises an inner surface  973 , a shelf  981 , one or more head clearance holes  976 , a chamfer surface  978 , a barrel inner wall  980 , a barrel outer wall  982 , and a barrel end  983 . A backer plate ring  975  having one or more shaft clearance holes  977  may be positioned within the holding ring  970 . 
         [0006]    The ring protrusion  999  of the retaining ring  990  and the barrel  979  of the holding ring  970  pass through the apertures  968 B of respective filter cloths  968  such that the inner surfaces  973 ,  993  of the radial projections  971 ,  998  abut an annular surface of the filter cloth  968  and such that the barrel outer wall  982  and ring protrusion outer wall  994  are surrounded by filter cloth apertures  968 B. When assembled, the barrel end  983  rests against the shelf  996 , the barrel outer wall  982  engages ring protrusion inner wall  995 , and ring protrusion end  991  rests against shelf  981 . 
         [0007]    One or more fasteners  974  pass through head clearance holes  976 ,  992  and shaft clearance holes  977 ,  997  of the holding ring  970  and retaining ring  990 , respectively, and engage the bores  106  in the first filter plate  100 . When fasteners  974  are tightened, the filter cloths  968  are secured to the filter plate  100  by virtue of the retaining properties of radial projections  971 ,  998 . Because a large amount of space is needed to gain access to and remove fasteners  974 , it is very difficult or nearly impossible to change filter cloths  968  on such assemblies  9 , even when the filter plates  100  are separated by their maximum distance. Moreover, the use of two different geometries for retaining ring  990  and holding ring  970  increases manufacturing and inventory costs. 
       OBJECTS OF THE INVENTION 
       [0008]    It is, therefore, an object of the invention to provide a filter cloth that can be easily be replaced without removing filter plates from the filter press plate stack. 
         [0009]    It is yet another object of the invention to provide a competitive solution for quick filter cloth changes, while still providing all of the widely accepted benefits and advantages associated with lower feed port feeding processes. 
         [0010]    Moreover, it is an object of the invention to provide a retrofittable solution for quick filter cloth changes at the preference of the customer, at any time, on an aftermarket basis. 
         [0011]    These and many other objects of the invention will be apparent from the drawings and description herein. Although every object of the invention is believed to be attained by at least one embodiment of the invention, there is not necessarily any one embodiment of the invention that achieves all of the objects of the invention. 
       SUMMARY OF THE INVENTION 
       [0012]    A filter plate assembly may comprise a filter plate having a recess, a radially-inwardly extending shelf portion having a seat surface, and a feed eye aperture extending through the shelf portion. An adapter ring may be placed within said recess and may comprise a tapered surface which is complimentary in shape with a tapered surface forming said recess. The adapter ring may have a flange and a barrel extending from the flange. The barrel may have an inner wall and an outer wall, and may be positioned within said aperture such that the outer wall of the barrel is in close proximity with said aperture, for example, by interference fit, press fit, a snug fit, a zero tolerance fit, a snap or other connection, a taper lock fit, or a loose fit. 
         [0013]    The flange may comprise an inner surface which abuts the seat surface. The filter plate assembly may further comprise a filter cloth assembly composed of a filter cloth having an aperture, and a grommet fitted within the filter cloth aperture. The grommet may be configured to align with the adapter ring, and may comprise a collar having an inner surface which can be bonded or mechanically attached to a first side of the filter cloth. The sealing surface of the collar may comprise at least one annular rib or groove defining a serpentine profile, and the adapter ring may comprise a backer plate ring for rigidity and support. A ring may extend from the collar, the ring being positioned within said barrel such that an outer wall of the ring is in close proximity with an inner wall of the barrel. A second side of the filter cloth may abut a sealing surface of the adapter ring. In some embodiments, a clearance hole may be provided to the flange, and the shelf portion of the filter plate may comprise a bore. At least one fastener may pass through the clearance hole and into the bore, in order to secure the adapter ring to the filter plate. The bore may be a threaded bore, and the at least one fastener may be an externally-threaded fastener which threadedly engages said bore. In some instances, the bore may be a clearance bore, and the at least one fastener may be an internally-threaded, smooth shank barrel bolt fastener which slidingly fits within the bore and is configured to receive an externally threaded fastener. In other embodiments, the bore may be a clearance bore, and the at least one fastener may be an externally-threaded fastener which fits within an internally-threaded fastener. 
         [0014]    The grommet may comprise a plurality of bosses, each having an abutment surface. Each boss may have tapered sidewalls with valleys being interposed between the bosses in alternating arrangement. At least one of the valleys may be oriented towards a bottommost portion of the feed eye assembly, such that it extends towards a bottom portion of the filter plate. An external portion of the grommet may comprise an external seal surface, and an internal portion of the adapter ring may comprise a complimentary internal seal surface. Two adapter rings and two filter cloth assemblies may be provided on opposing sides of the filter plate. A durometer of the adapter ring may be lower than the durometer of the grommet. 
         [0015]    A filter cloth assembly is also disclosed. The assembly may comprise a filter cloth having a first side, a second side, and an aperture extending therethrough. The filter cloth assembly may further comprise a grommet fitted within the filter cloth aperture, and the grommet may have a collar and a ring extending from the collar. The ring may protrude through the aperture and may be configured for positioning within a barrel of an adapter ring or a feed eye aperture. The collar may comprise an inner surface which may be bonded or mechanically attached to the first side of the filter cloth such that the second side of the filter cloth abuts a sealing surface. The grommet may further comprise a number of bosses, each having an abutment surface. 
         [0016]    A universal filter cloth system is also disclosed. The system may comprise a filter cloth assembly composed of a filter cloth and grommet. The filter cloth may have a first side, a second side, and an aperture extending therethrough. The grommet may be fitted within the filter cloth aperture. The grommet may comprise a collar and a ring extending from the collar. The ring may be configured for positioning within a barrel of an adapter ring or a feed eye aperture. The collar may comprise an inner surface which is bonded to the first side of the filter cloth. The grommet may also comprise a number of bosses, each boss having an abutment surface. The filter cloth assembly may be used with a first filter plate assembly comprising a first filter plate having an adapter ring positioned adjacent a feed eye aperture. The same filter cloth assembly may also be used with a second filter plate assembly comprising a second filter plate and a feed eye aperture, wherein the second filter plate has a different geometry than the first filter plate. The grommet of the filter cloth assembly may be configured to be fitted into the adapter ring of the first filter plate assembly. The grommet of the filter cloth assembly may also be configured to be fitted into the feed eye aperture of the second filter plate assembly. 
         [0017]    The adapter ring may comprise a sealing surface thereon, and the second filter plate may also comprise a sealing surface thereon. The second side of the filter cloth may be configured to abut either sealing surface to prevent slurry from passing between the grommet and feed eye aperture. In some embodiments, the sealing surfaces may comprise at least one of an annular rib, a groove, or an o-ring which defines a serpentine profile. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is front plan view of a conventional filter plate; 
           [0019]      FIG. 2  is a partial isometric cross-sectional view of the conventional filter plate assembly shown in  FIG. 1 ; 
           [0020]      FIG. 3  is a front plan view of a first filter plate assembly according to some embodiments of the invention; 
           [0021]      FIG. 4  is a partial cross-sectional view of the filter plate assembly shown in  FIG. 3 ; 
           [0022]      FIG. 5  is an isometric view of  FIG. 5 ; 
           [0023]      FIG. 6  is a partial cross-sectional view of a second filter plate assembly according to yet other embodiments; and 
           [0024]      FIG. 7  is an isometric view of  FIG. 6 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]    As shown in  FIG. 3 , a first filter plate assembly  1  is provided. First filter plate assembly  1  comprises a first filter plate  100  defined by a base portion  104  having standoffs  120 , peripheral walls  130 , and a shelf portion  108 . The shelf portion  108  is generally composed of a seat surface  101 , a recess  102 , a tapered surface  103 , and a feed eye aperture  110 . Chamfers  112  surround the feed eye aperture  110 , and a plurality of bores  106  are provided within the shelf portion  108 . 
         [0026]    The first filter plate assembly  1  further comprises a first feed eye assembly  140 . The first feed eye assembly  140  comprises at least one filter cloth assembly  160 . The filter cloth assembly  160  further comprises a filter cloth  168  having a first side  188 , a second side  189 , and an aperture  168 B which extends from the first side  188  to the second side  189 . The filter cloth assembly  160  further comprises a separate grommet  168 A provided within the aperture  168 B. The grommet  168 A comprises a longitudinally-extending ring  164  having a ring inner wall  163  and a ring outer wall  166 . The grommet  168 A further comprises a radially-extending collar  167  having an undersurface  167 A configured for securing to the filter cloth  168 . The first side  188  of the filter cloth  168  may be bonded to the undersurface  167 A of the collar  167  using chemical means, ultrasonic welding, staples, tacks, adhesives, friction welding, stitching, embedding, or other mechanical fastening means. 
         [0027]    A plurality of bosses  165  are also provided on the grommet  168 A. Each boss  165  comprises at least one sidewall  169 , and an abutment surface  165 A which is configured to contact an abutment surface  165 A of an adjacent boss  165  provided on an adjacent filter plate assembly  1 . One or more valleys  161  are formed between the sidewalls  169  and extend between the bosses  165 . The valleys  161  provide a channel for egress of slurry from within the feed eye assembly  140  to the filter chamber area defined between standoffs  120  and peripheral wall  130 , where cake formation occurs. Sidewalls  169  are preferably tapered by an acute angle  192  (measured from a theoretical longitudinal feed eye axis  190 ) in order to reduce slurry buildup and/or clogging in valleys  161 . At least one of the valleys  161  may preferably be oriented towards a bottom portion  132  of the feed eye assembly  140 , such that it extends downwardly with respect to the first filter plate  100 . An external seal surface  162  may be provided to the grommet  168 A, which spans between the collar  167  and the ring  164 . An oblique internal surface  163 A may also be provided to the grommet  168 A, in order to improve slurry flow between filter plate assemblies  1  and help residual slurry fall away from the ring inner wall  163 . 
         [0028]    The first filter plate assembly  1  further comprises a first adapter ring  170  having a radially-extending flange  172  and an axially-extending barrel  179  formed between a barrel inner wall  180 , a barrel outer wall  182 , and a barrel end  183 . The barrel  179  may comprise one or more sealing features such as a lip  181 . A second adapter ring  170 ′ may be used in combination with the first adapter ring  170  to sandwich the first filter plate  100  as shown in  FIGS. 4 and 5 . In some embodiments, the adapter rings  170 ,  170 ′ may have similar or identical geometries. As shown, the barrel  179  of the first adapter ring  170  may be configured with one or more sealing features  181  which interlockingly engage complimentary sealing features  181 ′ provided on the barrel  179 ′ of the second adapter ring  170 ′, thereby forming a leak-resistant serpentine path therebetween. 
         [0029]    The flange  172  may comprise a tapered surface  184  which is designed to prevent slurry from passing between the first adapter ring  170  and the first filter plate  100 . The flange  172  may also be configured with an inner surface  173  for abutting the seat surface  101  of the filter plate&#39;s shelf portion  108 . Flange  172  may further be provided with an outer sealing surface  185  comprising one or more annular ribs or grooves  171 . A backer plate ring  175  may be provided within portions of the adapter rings  170 ,  170 ′ for example within the flange  172 , in order to stiffen and strengthen the overall structure of the adapter rings  170 ,  170 ′. In the shown embodiment, flange  172  comprises a shaft clearance hole  177  through the backer plate ring  175 , and head clearance hole  176  suitable for either an externally-threaded fastener  174 A or an internally-threaded barrel bolt fastener  174 B to pass through. Adapter rings  170 ,  170 ′ provided on opposing sides of a first filter plate  100  are joined to the first filter plate  100  by first placing one or more externally-threaded fasteners  174 A and one or more internally-threaded barrel bolt fasteners  174 B through bores  106  in the shelf portion  108 , and then threadedly connecting them. The fasteners  174 A,  174 B are then tightened to clamp the adapter rings  170 ,  170 ′ to the first filter plate  100 . In some embodiments, the adapter rings  170 ,  170 ′ may comprise an internal seal surface  178  which is tapered and complimentary to the external seal surface  162  of grommet  168 A. 
         [0030]    Prior to use, first filter plate  100  and adapter rings  170 ,  170 ′ are secured together in the manner previously mentioned. The barrel  179  of each adapter ring  170 ,  170 ′ is received in the feed eye aperture  110 , and the flange  172  of each adapter ring  170 ,  170 ′ is received in the recess  102  of the first filter plate  100 . Fasteners  174 A,  174 B secure the adapter rings  170  to the first filter plate  100 . In the particular embodiment shown in  FIGS. 4 and 5 , a first adapter ring  170  on one side of the filter plate comprises an externally-threaded fastener  174 A and a second adapter ring  170 ′ on the opposite side of the filter plate comprises an internally-threaded barrel bolt fastener  174 B which threadedly accepts the externally-threaded fastener  174 A. Both fasteners  174 A,  174 B extend through bore  106 . While not shown, it is anticipated that the bore  106  may be a threaded bore, and both fasteners  174 A,  174 B may instead be shortened externally-threaded fasteners which threadedly engage said internally-threaded bore  106  from opposing sides. 
         [0031]    Filter cloth assembly  160  can be installed with the first filter plate assembly  1  by first spreading the stack of first filter plates  100  in the filter press, dropping the filter cloth assembly  160  between the stack of first filter plates  100 , and then pressing the ring  164  of the grommet  168 A into the inner wall  180  of the barrel  179  by hand or with an elongated tool. Removal of filter cloth assembly  160  is done in an opposite manner by first spreading the stack of first filter plates  100  in the filter press and then pulling the ring  164  of the grommet  168 A out of the respective adapter ring  170 ,  170 ′. 
         [0032]    Filter cloth assembly  160  can also be installed into a second filter plate assembly  5  having different geometries than the first filter plate assembly  1 , by first spreading the stack of second filter plates  200  in the filter press and then pressing the ring  164  of the grommet  168 A directly into the feed eye aperture  210  of a second feed eye assembly  240  provided in one of the second filter plates  200 , without the need for adapter plates  170 ,  170 ′. The external seal surface  162  on the grommet  168 A may sit flush in sealing arrangement with one or more chamfers  212  surrounding the feed eye aperture  210 . The second filter plate assembly  5  shown in  FIGS. 6 and 7  is similar to the first filter plate assembly  1  in that the second filter plate assembly  5  similarly comprises a seat surface  201 , one or more standoffs  220 , and a peripheral wall  230 . However, the second filter plate assembly  5  differs from the first filter plate assembly  1  by further comprising one or more grooves  250  within the seat surface  201 , wherein each groove  250  holds an o-ring  271  or equivalent seal or packing means. The o-ring(s)  271  prevent slurry and filtrate from moving between the second filter plate  200 , the grommet  168 A, and the filter cloth  168 , thereby reducing potential wear. Removal of filter cloth assembly  160  is done in an opposite manner by first spreading the stack of second filter plates  200  in the filter press and then pulling the ring  164  of the grommet  168 A from the feed eye aperture  210  and breaking all seals between chamfers  212  and external seal surface  162 . 
         [0033]    A contractor or other entity may provide a filter plate assembly, or operate a filter plate assembly configured with a filter cloth assembly in whole, or in part, as shown and described. For instance, the contractor may receive a bid request for a project related to designing or operating a filter plate or filter cloth apparatus, or the contractor may offer to design such a system or a process for a client. The contractor may then provide, for example, any one or more of the devices or features thereof shown and/or described in the embodiments discussed above. The contractor may provide such devices by selling those devices or by offering to sell those devices. The contractor may provide various embodiments that are sized, shaped, and/or otherwise configured to meet the design criteria of a particular client or customer. The contractor may subcontract the fabrication, delivery, sale, or installation of a component of the devices disclosed, or of other devices used to provide said devices. The contractor may also survey a site and design or designate one or more storage areas for stacking the material used to manufacture the devices, or for storing the devices and/or components thereof. The contractor may also maintain, modify, or upgrade the provided devices. The contractor may provide such maintenance or modifications by subcontracting such services or by directly providing those services or components needed for said maintenance or modifications, and in some cases, the contractor may modify preexisting filter presses, filter plates, filter cloth apparatus, assemblies, or parts thereof with a “retrofit kit” to arrive at a modified device comprising one or more method steps, devices, components, or features of the systems and processes discussed herein. 
         [0034]    Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed. 
         [0035]    For instance, while not shown, rings  164  may be omitted from grommets  168 A in certain instances, such as to facilitate the installation and removal of filter cloth assemblies. Moreover, while not shown, in some embodiments, filter cloth  168  may be overmolded within collar  167  or otherwise captured within a peripheral circumferential groove provided within collar  167 . Additionally, instead of o-rings  271  provided within grooves  250 , one or more annular projections may be provided which integrally and monolithically extend from the second filter plate  200 , and which are composed of the same material as the second filter plate  200 . 
         [0036]    Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof. 
         [0000]    
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 Reference numeral identifiers 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                  1 
                 First filter plate assembly 
               
               
                   
                  5 
                 Second filter plate assembly 
               
               
                   
                  9 
                 Conventional filter plate assembly 
               
               
                   
                 100 
                 First filter plate 
               
               
                   
                 101 
                 Seat surface 
               
               
                   
                 102 
                 Recess 
               
               
                   
                 103 
                 Tapered surface 
               
               
                   
                 104 
                 Base portion 
               
               
                   
                 106 
                 Bore 
               
               
                   
                 108 
                 Shelf portion 
               
               
                   
                 110 
                 Feed eye aperture 
               
               
                   
                 112 
                 Chamfer 
               
               
                   
                 120 
                 Standoff 
               
               
                   
                 130 
                 Peripheral wall 
               
               
                   
                 132 
                 Bottom portion 
               
               
                   
                 140 
                 First feed eye assembly 
               
               
                   
                 160 
                 Filter cloth assembly 
               
               
                   
                 161 
                 Valley 
               
               
                   
                 162 
                 External seal surface 
               
               
                   
                 163 
                 Ring inner wall 
               
               
                   
                 163A 
                 Oblique internal surface 
               
               
                   
                 164 
                 Ring 
               
               
                   
                 165 
                 Boss 
               
               
                   
                 165A 
                 Abutment surface 
               
               
                   
                 166 
                 Ring outer wall 
               
               
                   
                 167 
                 Collar 
               
               
                   
                 167A 
                 Undersurface 
               
               
                   
                 168 
                 Filter cloth 
               
               
                   
                 168A 
                 Grommet 
               
               
                   
                 168B 
                 Aperture 
               
               
                   
                 169 
                 Sidewall 
               
               
                   
                 170 
                 Adapter ring 
               
               
                   
                 170′ 
                 Adapter ring 
               
               
                   
                 171 
                 Annular rib or groove 
               
               
                   
                 172 
                 Flange 
               
               
                   
                 173 
                 Inner surface 
               
               
                   
                 174A 
                 Externally-threaded fastener 
               
               
                   
                 174B 
                 Internally-threaded barrel bolt fastener 
               
               
                   
                 175 
                 Backer plate ring 
               
               
                   
                 176 
                 Head clearance hole 
               
               
                   
                 177 
                 Shaft clearance hole 
               
               
                   
                 178 
                 Internal seal surface 
               
               
                   
                 179 
                 Barrel 
               
               
                   
                 179′ 
                 Barrel 
               
               
                   
                 180 
                 Barrel inner wall 
               
               
                   
                 181 
                 Outer interlocking feature (e.g., sealing lip) 
               
               
                   
                 181′ 
                 Inner interlocking feature (e.g., sealing lip) 
               
               
                   
                 182 
                 Barrel outer wall 
               
               
                   
                 183 
                 Barrel end 
               
               
                   
                 184 
                 Tapered surface 
               
               
                   
                 185 
                 Sealing surface 
               
               
                   
                 188 
                 First side of filter cloth 
               
               
                   
                 189 
                 Second side of filter cloth 
               
               
                   
                 190 
                 Longitudinal feed eye axis 
               
               
                   
                 192 
                 Acute angle 
               
               
                   
                 200 
                 Second filter plate 
               
               
                   
                 201 
                 Seat surface 
               
               
                   
                 210 
                 Feed eye aperture 
               
               
                   
                 212 
                 Chamfer 
               
               
                   
                 220 
                 Standoff 
               
               
                   
                 230 
                 Peripheral wall 
               
               
                   
                 240 
                 Second feed eye assembly 
               
               
                   
                 250 
                 Groove 
               
               
                   
                 271 
                 O-ring 
               
               
                   
                 940 
                 Conventional feed eye assembly 
               
               
                   
                 968 
                 Filter cloth 
               
               
                   
                 968B 
                 Aperture 
               
               
                   
                 970 
                 Holding ring 
               
               
                   
                 971 
                 Radial projection 
               
               
                   
                 973 
                 Inner surface 
               
               
                   
                 974 
                 Fastener 
               
               
                   
                 975 
                 Backer plate ring 
               
               
                   
                 976 
                 Head clearance hole 
               
               
                   
                 977 
                 Shaft clearance hole 
               
               
                   
                 978 
                 Chamfer surface 
               
               
                   
                 979 
                 Barrel 
               
               
                   
                 980 
                 Barrel inner wall 
               
               
                   
                 981 
                 Shelf 
               
               
                   
                 982 
                 Barrel outer wall 
               
               
                   
                 983 
                 Barrel end 
               
               
                   
                 990 
                 Retaining ring 
               
               
                   
                 991 
                 Ring protrusion end 
               
               
                   
                 992 
                 Head clearance hole 
               
               
                   
                 993 
                 Inner surface 
               
               
                   
                 994 
                 Ring protrusion outer wall 
               
               
                   
                 995 
                 Ring protrusion inner wall 
               
               
                   
                 996 
                 Shelf 
               
               
                   
                 997 
                 Shaft clearance hole 
               
               
                   
                 998 
                 Radial projection 
               
               
                   
                 999 
                 Ring protrusion