Abstract:
In a brick molding apparatus, the improvement includes a mechanical drive assembly for indexing in predetermined incremental movements a mold adapted to receive and shape clay slugs into green bricks. The drive assembly includes a conveyor for carrying the mold in the brick molding apparatus. A drive gear is mounted on a drive shaft and defines a plurality of circumferentially-spaced teeth and radially-extending slots. The drive shaft is operatively connected to the conveyor. A drive lug is adapted for movement into and out of a selected one of the plurality of slots formed in the drive gear. A gear actuator is adapted for moving the drive lug in a rotational direction relative to the drive shaft. When the drive lug is positioned in the selected slot of the drive gear, the gear actuator causes rotation of the drive gear and drive shaft thereby indexing the conveyor and mold.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to a brick molding apparatus, and more specifically to a mechanical drive assembly adapted for moving a section of the apparatus in predefined increments in a continuous loop for receiving, molding, and discharging green brick. The present apparatus is especially applicable for manufacturing brick which closely resembles a traditional “hand thrown” product. As compared to conventional machine-made brick, brick made by hand is generally more attractive, and can be produced in a wider variety of colors and texture. A significant disadvantage of this product, however, is the labor intensive and time consuming manufacturing process. 
     The key value of a successfully molded hand-thrown brick lies in the aesthetic visual appearance of the finished product. The physical size of the brick is controlled by the dimension of the mold cavity. More difficult to achieve are the elements of color, finish texture, and other irregularities in shape or surface texture that are obtained during the hand molding process. Bricks thus produced are distinctive in appearance and popular with commercial and residential builders as well as architects and home design professionals. At first glance, it would seem that the only problem to resolve would be to increase volume enough to satisfy demand. This problem could be solved, then, by hiring more molders or designing a machine to produce bricks at a higher rate than is possible using manpower. If volume were the only consideration, the machines developed to meet the demand for hand made (or hand thrown) bricks would have satisfied that demand. With more attention given to an evaluation of the product usage, units sold per lot size, style, color, texture, the like, it has been noticed that hand thrown brick sales do not follow the same patterns as standard bricks, and that the requirements for a machine to simulate hand thrown bricks are considerably different than originally envisioned. 
     To successfully re-create this product mechanically, any machine designed to produce simulated hand-thrown bricks must be able to mold a high quality product, consistently, and at the same time be flexible enough to manufacture short run special orders for custom design shapes, colors and textures. This need creates a formidable challenge for the hand-thrown brick market—the ability to meet the high-end “designer-type” products without losing time to modify the machine tools and/or materials. While several machines currently available in the industry are able to produce bricks which appear to be hand thrown, the machines are maintenance nightmares and are unable to quickly change either brick size (replace molds) or brick color/texture (change in tooling) to meet the requirement for custom demands. 
     BRIEF SUMMARY OF THE INVENTION 
     Therefore, it is an object of the invention to provide a brick molding apparatus which creates brick that closely resembles a hand-thrown product. 
     It is another object of the invention to provide a brick molding apparatus which enables the production of custom-designed bricks in a cost efficient manner. 
     It is another object of the invention to provide a brick molding apparatus which is capable of simultaneously manufacturing a variety of colored bricks during a single production run without requiring color changeovers. 
     It is another object of the invention to provide a brick molding apparatus which is capable of doing a short color run without losing valuable production time. 
     It is another object of the invention to provide a brick molding apparatus which can be readily and conveniently modified to adjust the brick size. 
     It is another object of the invention to provide a brick molding apparatus which requires relatively little floor space. 
     It is another object of the invention to provide a brick molding apparatus which is provides unique markings on the brick for identification. 
     It is another object of the invention to provide a brick molding process and apparatus which utilizes computer software developed for enabling a fully integrated operating system. 
     These and other objects of the present invention are achieved in the preferred embodiments disclosed below by providing a mold section of a brick molding apparatus adapted for receiving a plurality of individual clay slugs and molding the clay slugs into green bricks. The mold section includes first and second opposing spaced-apart end plates extending from one end of the mold section to the other. A plurality of spaced-apart side plates are perpendicularly disposed between the opposing end plates. A plurality of adjustable base plates are positioned between the end plates and the side plates. The end plates, side plates, and base plates cooperate to form respective end, side, and bottom walls of a plurality of individual mold cavities. Each of the mold cavities has a length defined by a distance between the opposing end plates, a width defined by a distance between adjacent ones of the side plates, and a depth defined by a distance between the base plate and an open top of the mold cavity. An adjustable base plate support assembly engages the plurality of base plates to locate the base plates a predetermined distance from the open tops of the mold cavities, thereby adjustably setting of the depths of the mold cavities. 
     According to another preferred embodiment of the invention, the base plate support assembly includes a plurality of base beams located beneath respective base plates and adapted for positioning the base plates within the mold cavities. 
     According to another preferred embodiment of the invention, the base plate support assembly further includes a cross beam extending from one end of the mold section to the other. The cross beam carries each of the base beams to effect simultaneous position adjustment of the base plates within the mold cavities. 
     According to another preferred embodiment of the invention, the base plate support assembly further includes first and second cross beam mounting plates attached to respective opposite ends of the cross beam for supporting the cross beam beneath the mold cavities. 
     According to another preferred embodiment of the invention, opposing mold section mounting plates are located at opposite ends of the mold section for supporting the mold section on respective guide rails of the brick molding apparatus. 
     According to another preferred embodiment of the invention, the base plate support assembly further includes first and second vertical guide shafts having respective top-and bottom ends. The bottom ends of the guide shafts pass vertically through openings in respective cross beam mounting plates, and the top ends of the guide shafts are secured to respective mold section mounting plates. 
     According to another preferred embodiment of the invention, the top ends of respective guide shafts are threaded and adapted for receiving complementary-threaded lock nuts. Threaded vertical movement of the guide shafts provides position adjustment of the cross beam and base plates relative to the mold cavities, thereby adjusting the depth of the mold cavities. 
     According to another preferred embodiment of the invention, the base plate support assembly further includes respective springs formed around the guide shafts between the cross beam mounting plates and the mold section mounting plates. The springs cooperate to normally urge the cross beam away from the mold cavities, such that the position of the base plates within the mold cavities is maintained upon inversion of the cross beam and mold cavities by the brick molding apparatus. 
     According to another preferred embodiment of the invention, a mold cavity end spacer is adapted for residing adjacent one of the end plates and between adjacent side plates of the mold cavity to adjust the length of the mold cavity. 
     According to another preferred embodiment of the invention, a pallet is removably positioned over the open top of the mold cavities, and extends from one end of the mold section to the other to hold the green bricks within the mold cavities upon inversion of the mold section by the brick molding apparatus. 
     In another embodiment, the invention is an adjustable mold cavity adapted for receiving a clay slug and molding the clay slug into a green brick. The mold cavity includes first and second opposing spaced-apart end plates forming respective end walls of the mold cavity. The end plates are spaced-apart a distance defining a length of the mold cavity. First and second opposing spaced-apart side plates are perpendicularly disposed between the opposing end plates and form respective side walls of the mold cavity. The side plates are spaced-apart a distance defining a width of the mold cavity. An adjustable base plate is positioned between the end plates and the side plates to form a bottom wall of the mold cavity. The base plate is spaced-apart from an open top of the mold cavity a distance defining a depth of the mold cavity. The adjustable base plate is adapted for movement relative to the end and side plates to adjust the desired depth of the mold cavity. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     Some of the objects of the invention have been set forth above. Other objects and advantages of the invention will appear as the description proceeds when taken in conjunction with the following drawings, in which: 
     FIG. 1 is a plan view of a brick molding facility employing a brick molding apparatus according to one preferred embodiment of the invention; 
     FIG. 2 is a side elevation of the wet sand supply assembly located adjacent the clay extrusion assembly of the brick molding apparatus; 
     FIG. 3 is a side elevation of the clay extrusion assembly; 
     FIG. 4 is a top plan view of the wet sand supply system illustrating delivery of wet sand to the sand tubs of the clay extrusion assembly; 
     FIG. 5 is a side elevation of an extruder head and showing the attached rotary extrusion processing assembly; 
     FIG. 6 is a top plan view of the extruder head and attached rotary extrusion processing assembly; 
     FIG. 7 is an end elevation of the brick molding apparatus with the throw belts removed for clarity; 
     FIG. 8 is an end elevation of the brick molding apparatus with the throw belts included; 
     FIG. 9 is an elevational view of the throw belts; 
     FIG. 10 is a fragmentary top plan view of a portion of the mold section; 
     FIG. 10A is an enlarged, fragmentary side elevation showing one end of a portion of the mold section; 
     FIG. 11 is an end elevation showing the individual mold cavities of the mold section; 
     FIG. 12 is a side elevation of the mold conveyor of the brick molding apparatus; 
     FIG. 13 is a fragmentary elevational view showing the discharge end of the mold conveyor; 
     FIG. 14 is an elevational view of the drive gear used for actuating the mold conveyor; 
     FIG. 15 is an end elevation of a mold section showing the clamping assembly used for clamping the pallet to the mold section; 
     FIG. 16 is a fragmentary top plan view showing one end of a portion of the mold section; 
     FIG. 17 is a fragmentary side elevation showing one end of a portion of the mold section, and demonstrating operation of the clamping arm for holding the pallet on the mold section; 
     FIG. 18 is a side elevation of a chain conveyor employed in the brick molding process of the present invention; 
     FIG. 19 is a top plan view of the chain conveyor; 
     FIG. 20 is a top plan view of a pallet shuttle employed in the brick molding process of the present invention; 
     FIG. 21 is a side elevation of the pallet shuttle; 
     FIG. 22 is an end elevation of the pallet shuttle; 
     FIG. 23 is a side elevation of a pallet elevator employed in the brick molding process of the present invention; 
     FIG. 24 is a top plan view of the pallet elevator; 
     FIG. 25 is a view of the horizontal drive assembly of the pallet elevator; 
     FIG. 26 is a view of the vertical drive assembly of the pallet elevator; 
     FIG. 27 is a side elevation of the brick stripper assembly employed in the brick molding process of the present invention; 
     FIG. 28 is a top plan view illustrating a portion of the magnetic pallet spotter; 
     FIG. 29 is a side elevational view of the discharge end of the chain conveyor used for moving the pallets to the pallet inversion station; 
     FIG. 30 is a side elevation of the pallet inversion station; and 
     FIG. 31 is an end elevation of the pallet inversion station, and showing the horizontal conveyor assembly and magnetic pallet spotter which cooperate to receive and transfer the inverted pallets onto the mold section of the mold conveyor. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now specifically to the drawings, a brick molding apparatus according to the present invention is illustrated in FIG.  1  and shown generally at reference numeral  10 . The brick molding apparatus  10  is especially applicable for manufacturing bricks which resemble a traditional hand-thrown product. 
     Overview of Brick Molding Process 
     As shown in FIG. 1, the brick molding apparatus  10  includes a clay extrusion assembly  20  which receives clay from a conveyor (not shown), extrudes the clay, and applies wet sand delivered from a wet sand supply assembly  30 . The extruded clay is then cut into slugs and thrown into respective cavities of a mold conveyor  40 . The mold conveyor  40  transfers the molded clay slugs on a pallet to a chain conveyor “C1”. The chain conveyor “C1” moves the pallets downstream away from the mold conveyor  40  for the loading into transport racks “R”. The transport racks “R” pass through a dryer room “D” and over to conveyor “C2” where the pallets are removed from the racks “R”. Conveyor “C2” moves the loaded pallets to a brick stripper station  60  where the dried bricks are unloaded and transferred to an oven “O” for final processing. The empty pallets are then transferred onto conveyor “C3” and moved downstream for re-loading into the transport racks “R”. The transport racks “R” move the empty pallets to a storage area “S”. From the storage area “S”, the empty pallets are transported to a chain conveyor “C4” which moves the pallets to a pallet inversion station  80 . In the pallet inversion station  80 , the pallets are inverted and returned to the mold conveyor  40 . 
     Clay Preparation and Delivery 
     Clay used in the brick molding process of the present invention is first processed in a grinding room and then delivered to a clay storage bin upstream of first and second pug mills (not shown). Each pug mill includes a mixing housing jacketed by a steam-heated chamber, and a centrally-disposed longitudinal rotating shaft and paddle assembly. As clay is fed from the storage bin into the first pug mill, warm water is added to the clay while the paddle assembly mixes the clay and water to the proper consistency at the selected temperature maintained by the outer steam chamber. The clay/water mixture passes through both pug mills, and is moved by a conveyor to a clay hopper  102  of the extrusion assembly  20  shown in FIG.  3 . Six motor-driven rotating shafts  104  (only three shown) are longitudinally-disposed within the clay hopper  102 , and include respective mixing paddles  106  operating to maintain proper consistency of the of the clay mix prior to extruding. The terminal end each shaft  104  defines a longitudinal auger  108  which receives and moves the clay mix downwardly through an extruder head  110  and outwardly from a first forming die  112  positioned above a wet sand tub  114 . The extrusion assembly  20  preferably includes six extruder heads  110  and six wet sand tubs  114  arranged in two rows of three. 
     Wet Sand Storage and Delivery 
     The clay mix exits each of the six extruder heads  110  and forming dies  112  (only three shown) in the shape a continuous length column, and is further shaped by a flexible rubber die  116  formed with a center opening through each of the wet sand tubs  114 , as shown in FIG.  4 . Wet sand contained in the sand tubs  114  is applied to each of the moving clay columns by means of respective rotary extrusion processing assemblies  118 , described below. In order to maximize its flexibility of operation, each of the six extruder heads  110  of the brick molding apparatus  10  must be capable of producing a different colored brick. To achieve this, each extruder head  110  is served by its own wet sand supply to the sand tub  114 . 
     Referring to FIGS. 2 and 4, the wet sand supply assembly  30  is located adjacent the clay extrusion assembly  20 , and includes an asymmetrical sand delivery cone  120  rotatably mounted to a vertical drive shaft  122  extending above six divided wet sand hoppers  124 . The drive shaft  122  is powered by a drive chain  126  and cone motor  128 . Actuation of the drive shaft  122  rotates the sand delivery cone  120  through a 360-degree path such that the feed end of the cone  120  can be positioned over each of the six wet sand hoppers  124 . A vibrator  130  is preferably mounted to the exterior of the sand delivery cone  120  to promote the flow of wet sand outwardly through the feed end and into the selected wet sand hopper  124 . As shown in FIGS. 2 and 4, a rotary conveyor assembly  132  is located at the base of the wet sand hoppers  124 , and includes six rotary augers  134  arranged at the open bottom of the sand hoppers  124  and extending horizontally to respective wet sand tubs  114  positioned beneath the extruder heads  110 . The rotary augers  134  operate to transport the wet sand exiting the sand hoppers  124  to the wet sand tubs  114 . Preferably, vibrators  136  are mounted to each of the sand hoppers  124  to promote the flow of wet sand outwardly to the rotary augers  134  and to prevent the occurrence of sand “bridging”. 
     Rotary Extrusion Processing Assembly  118   
     Referring to FIGS. 5,  6 , and  7 , a rotary extrusion processing assembly  118  is provided for each of the six extruder heads  110  to mark and further process the moving clay extrusion. Each assembly  118  includes a stationary roller track  138  fixed to an annular mounting flange  140  welded to the exterior of the extruder head  110 . A number of spaced-apart V-grooved roller runners  142  are carried on the track  138 , and attached to an annular double-grooved revolving sheave  144 . The runners  142  are preferably spaced-apart evenly around the circumference of the roller track  138 , and are adapted for being actuated by respective drive belts  146  positioned within the grooves and extending laterally from one side of the clay extrusion assembly  20  to the other. The drive belts  146  are operatively connected to opposing drive pulleys  148 A and  148 B, shown in FIG.  7 . As previously indicated, the clay extrusion assembly  20  includes two rows of three laterally-spaced extruder heads  110 . Thus, a first assembly of drive belts  146  and pulleys  148 A,  148 B serves to actuate the revolving sheave  144  on each of the first row of extruder heads  110 , while a second assembly of drive belts  146  and pulleys  148 A,  148 B actuates the revolving sheave  144  on each of the second row of extruder heads  110 . The drive pulleys  148 A,  148 B cooperate to move the revolving annual sheave  144  360-degrees around the circumference of each of the roller tracks  138  of the extruder heads  110 . 
     The revolving annular sheave  144  carries any number of pivotable cam shafts  152  vertically mounted within a bearing box  154  and extending downwardly through the revolving sheave  144  towards the sand tub  114 . A cam arm  156  is attached to a cam body clamp  158  mounted to the pivotable cam shaft  152  below the revolving sheave  144 , and is spring loaded to normally urge the cam arm  156  inwardly towards the center of the extruder head  110 . Any number of stationary arm-engaging posts  160  are mounted to the underside of the roller track  138 , and extend downwardly to operatively engage the cam arms  156  upon movement of the revolving sheave  144  along the circumference of the roller track  138 . One or more radially-extending clay-processing tools, such as a sand spoon  162  and clay probe  164 , is attached to a terminal end of the cam shaft  152 , and is actuated upon pivoting movement of the shaft  152  caused by engagement of the spring-loaded cam arm  156  and posts  160 . As the cam arm  156  engages the post  160 , the tool  162 ,  164  is forced in a direction towards the extruded clay column passing centrally through the second forming die  116  in the sand tub  114 . The sand spoon  162  is adapted for scooping together and applying the wet sand contained in the sand tub  114  onto the moving clay column. The sand spoons  162  are preferably spaced 180 degrees apart along the circumference of the roller track  138 . The clay probes  164  are preferably attached to each of the remaining cam shafts  152 . The clay probes  164  are adapted to intermittently engage the moving clay column in a manner creating impressions which result in unique identification patterns in the finished brick. 
     Clay Slug Formation and Throw 
     Referring to FIGS. 7,  8 , and  9 , as the moving clay column exits the wet sand tub  114  through the second forming die  116 , the column is cut laterally into brick-sized slugs by a lateral moving cutting wire  166 . The cutting wire  166  is carried by a trolley  168  actuated by a trolley cylinder  170 . Once cut, the clay slugs drop vertically between opposing, counter-rotating throw belts  172  and  174  which cooperate to “throw” the brick slug downwardly into a mold cavity of the mold conveyor  40  located below. As best shown in FIGS. 8 and 9, the throw belts  172 ,  174  are carried on respective drive rollers  176 A,  176 B and idle rollers  178 A,  178 B. The drive rollers  176 A,  176 B for each section of throw belts  172 ,  174  are interconnected and powered by a single drive chain  180  and motor  182 . Preferably, the spacing of the lower idle rollers  178 A,  178 B of each pair of throw belts  172 ,  174  is readily adjustable using a threaded adjustment screw  184 . This adjustment allows the user to either change the landing point of the slug in a given mold cavity to assure proper coverage, or to shape the slug to achieve a desired effect on the finished brick. In addition, the vertical spacing between the rollers  176 A,  176 B and  178 A,  178 B may also be adjusted using tension adjustment screws  186  to account for stretching of the throw belts  172 ,  174  over time. According to one embodiment, the throw belts  172 ,  174  are approximately four inches wide and eighteen inches long, respectively, and are spaced about four inches apart. 
     Mold Conveyor and Filling Station 
     Referring to FIGS. 8,  10 ,  10 A, and  11 , from the throw belts  172 ,  174 , the brick slugs are delivered into respective mold cavities  188  of the mold conveyor  40 . According to one embodiment, the mold conveyor  40  includes  40  12-cavity adjustable elongate mold sections  190  attached at respective opposite ends to continuous-loop drive chains  192  (See FIG. 12) located at opposite sides of the mold conveyor  40 . While the following description refers to only a single mold section  190 , it is understood that the remaining mold sections are identical in construction and operate in an identical manner to that described. 
     As shown in FIG. 10, the mold section  190  includes opposing, spaced-apart, longitudinal end plates  193  and  194  extending the entire length of the mold section  190 , and defining respective opposing end walls of the mold cavities  188 . The end plates  193  and  194  are joined at respective opposite ends to mold section mounting plates  196  (only one shown). Each mounting plate  196  is secured by axial bolt  198  to a chain link  192 A of the drive chain  192 . A guide wheel  200  is located between the head  198 A of the bolt  198  and the chain link  192 A to engage the outer guide rail  202  of the mold conveyor  40  during operation. The mold cavities  188  are further defined by a plurality of side plates  204  attached to each of the end plates  193  and  194 , and spaced-apart a predetermined distance to define opposing side walls of each mold cavity  188 . As best shown in FIGS.  1 OA and  11 , the bottoms of the mold cavities  188  are formed by respective base plates  206  mounted to respective base beams  208 . The short base beams  208  are carried by a single cross beam  210  ending from one end of the mold section  190  to the other, and including respective opposing cross beam mounting plates  212  cooperating with spring-loaded guide shafts  214  to support the cross beam  210  a predetermined distance from the mold cavities  188 . The guide shafts  214  are threaded at respective top ends, and are secured to the cross beam mounting plates  212  at their respective bottom ends using fixed shaft collars  216  and bushings  218 . The threaded top ends of the guide shafts  214  extend through respective internally-threaded openings of keeper plates  197 , and through respective openings in the mounting plates  196 . The guide shafts  214  are secured to the mold section mounting plates  196  using complementary-threaded lock nuts  220 . Releasing the lock nut  220  of each guide shaft  214  allows ready and convenient depth adjustment of the mold cavities  188  by enabling threaded vertical movement of the guide shaft  214  to manipulate the position of the base plate  206  relative to the end plates  193 ,  194  and side plates  204 . The length of each mold cavity is defined by the distance between the end plates  193  and  194 , and is likewise conveniently adjusted by inserting metal spacers  222  between the adjacent side plates  204 . The width of the mold cavity  188  is defined by the distance between adjacent side plates  204 . In addition, to maintain proper spacing between adjacent mold sections  190  during operation of the mold conveyor  40 , a frame rail spacer  224  is bolted to a top edge of the end plate  194 . 
     In order to fill all mold cavities  188  of the mold section  190 , the extruder heads  110  and throw belts  172  and  174  of the clay extrusion assembly  20  must travel over the mold conveyor  40  to inject a clay slug into each of the empty mold cavities  188 . As shown in FIGS. 7 and 8, to achieve this movement, the clay extrusion assembly  20  is mounted on base rollers  226  and actuated by a drive cylinder  228 . Opposing travel stops  230  and  232  define maximum lateral movement of the clay extrusion assembly  20  over the mold conveyor  40 . 
     After all cavities  188  of the mold section  190  are filled, the opposing drive chains  192  of the mold conveyor  40  cooperate to move the mold section  190  downstream of the filling station such that an empty mold section  190  can now be filled, as previously described. The drive chains  192  are attached at opposite ends of the mold conveyor  40  to respective first and second pairs of rotating conveyor sprocket wheels  234  and  236 , as best shown in FIG. 12. A drive shaft  238  extends through the second pair of conveyor sprocket wheels  236  at the discharge end of the mold conveyor  40 , and is operatively connected to a drive ratchet assembly  240  described below. 
     The drive ratchet assembly  240 , best shown in FIGS. 13 and 14, includes a drive gear  242  positioned adjacent the conveyor sprocket wheel  236  and fixed to the drive shaft  238  through a locking collar  243  secured to a bearing  244 . A pair of operating arms  246  (only one shown) are attached to the bearing  244  on either side of the drive gear  242 , and extend outwardly from the drive shaft  238  a prescribed distance beyond the outside diameter of the drive gear  242 . A slot along the length of each operating arm  246  defines a longitudinal lug track  248 . The lug track  248  receives a metal drive lug  250  adapted for inward and outward sliding movement within the track  248 . The drive lug  250  is powered by an attached drive-lug cylinder assembly  252  mounted on the end of the operating arms  246 . The drive-lug cylinder assembly  252  includes an extendable/retractable piston which operates to move the drive lug  250  between a retracted position, wherein the drive lug  250  is fully positioned within the track  248 , and an extended position, wherein the drive lug  250  enters into one of a plurality of radial slots  254  formed between respective adjacent teeth of the drive gear  242 . A master drive cylinder assembly  256  is mounted on the conveyor frame, and includes an extendable/retractable piston  258  attached to the underside of the operating arms  246 . 
     Movement of the mold conveyor  40  is effected by first actuating the drive-lug cylinder assembly  252  to move the drive lug  250  into the extended position within a slot  254  of the drive gear  242 . With the drive lug  250  in the extended position, the master drive cylinder assembly  256  is then actuated to move the piston  258  outwardly, thereby advancing the drive gear  242  a predetermined angular distance. As the drive gear  242  advances, the fixed drive shaft  238  rotates causing rotation of the attached conveyor sprocket wheels  234  and  236  and drive chains  192 . The drive chains  192  cooperate to index the mold section  190  downstream in a clockwise direction away from the mold filling station. Preferably, a compact roller (not shown) located adjacent the mold filling station rolls over the open top of the mold section  190  to help assure that all corners of the mold cavities  188  are properly filled. 
     Overfill Cutoff and Removal Station 
     Referring to FIGS. 7,  11 , and  12 , from the mold filling station, the mold section  190  moves downstream to an overfill cutoff and removal station where excess clay is sheared off the open top of the mold cavities  188  and removed for recycling. As best shown in FIGS. 7 and 11, this station includes a continuous-loop cutting wire  260  carried by guide pulleys  262 ,  264 ,  266 , and  268 , and actuated by drive cylinder  270  to produce a back-and-forth sawing-type motion. The guide pulleys  262 ,  264 ,  266 , and  268  are rotatably mounted to respective tension adjustment plates  272  and  274  secured to a frame member adjacent the clay extrusion assembly  20 . The lower section of the cutting wire  260  is positioned at a precise elevation relative to the mold section  190  such that any excess clay in the mold cavities  188  is sheared off by the sawing motion of the cutting wire  260 . 
     As shown in FIG. 12, as excess clay is removed by the cutting wire  260 , it is loaded onto an inclined conveyor assembly  276 . Preferably, a heat strip (not shown) extending the width of the mold conveyor  40  and located upstream of the inclined conveyor assembly  276  heats the excess clay to facilitate its loading onto the conveyor assembly  276 . The conveyor assembly  276  includes pick-up belt  278  spanning the entire width of the mold conveyor  40 , and carried by respective nose and head pulleys  280  and  282 . A drive chain  284  connects the head pulley  282  to a motor  286  which operates to drive the pick-up belt  278 . Upon reaching the upper end of the pick-up belt  278 , the excess clay is passed to a second conveyor assembly  279  which transports the clay away from the mold conveyor  40  for re-mixing with the next batch of clay. 
     Pallet Application Station 
     Referring to FIGS. 11,  13 ,  15 ,  16 , and  17 , prior to reaching the downstream end of the mold conveyor  40 , a pallet  290  is transferred from the pallet inversion station  80 , and applied over the open top of the mold section  190  in a pallet application station. The pallet  290  is secured to the mold section  190  by opposing releasable locking assemblies  292 A and  292 B. As shown in FIG. 11, upon application of the pallet  290  to the mold section  190 , an air cylinder  294  actuates a spring cushion  296  which extends outwardly to engage a pivoted holding lever  298 . The holding lever  298  is fixed at one end to a pallet clamping arm  300  and at an opposite end to a control pin  302 . The spring cushion  296  forces the holding lever  298  forward a distance defined by a travel slot  304  formed in the holding lever  298 . A compression spring  306  then urges the holding lever  298  upwardly against the biasing force of a torsion spring  308  attached to the pallet clamping arm  300 , such that the pallet clamping arm  300  extends over the pallet  290  to hold the pallet  290  in position upon inversion of the mold section  190  as it travels around the end of the mold conveyor  40 . 
     Upon movement of the mold section  190  around the downstream end of the mold conveyor  40 , as shown in FIG. 13, the pallet  290  remains clamped over the mold cavities  188  until engagement with a release mechanism  310  causing the clamping arms  300  to retract to their original open positions. The release mechanism engages the holding lever  298  which effects movement in a downward and rearward direction defined by the travel slot  304 . In this position, the biasing force of the torsion spring  308  is sufficient to hold the clamping arm  300  open against the force of the compression spring  306 . 
     Green Brick Ejector Station 
     Referring again to FIG. 13, once released, the pallet  290  falls downwardly onto a pair of spaced pallet transfer arms  311  (only one shown) of an elevator assembly  312 , while a brick ejector assembly  314  operates to eject the green bricks from the mold cavities  188  and onto the released pallet  290 . The brick ejector assembly  314  includes a drive cylinder  316  connected to a cam plate  318  pivotably mounted on a pivot shaft  320 . Cam push arms  322  are fixed to the cam plate  318 , and operate to engage the cross beam  210  of the mold section  190  (See FIG. 11) upon actuation of the drive cylinder  316  and pivoting movement of the cam plate  318 . As the cam push arms  322  engage the cross beam  210 , the cross beam  210  is urged against the biasing force of the spring-loaded guide shafts  214  in a direction towards the mold cavities  188 . This movement of the cross beam  210  causes simultaneous movement of the base plates  206  inside respective mold cavities  188 , thereby forcing the green bricks outwardly from the mold section  190  and onto the released pallet  290 . As the drive cylinder  316  retracts, the cam arms  322  disengage the cross beam  210  of the mold section  190 , while the spring-loaded guide shafts  214  return the cross beam  210  and base plates  206  of the mold section  190  to their original position. The loaded pallet  290  is then carried downwardly on the transfer arms  311  of the elevator assembly  312 . The elevator assembly  312  is actuated by control cylinders  324  attached to respective guide plates  326  on each side of the mold conveyor  40 . Each guide plate  326  includes a number of followers  328  which engage the cam track  330  as the transfer arms  311  are lifted and lowered. From the elevator assembly  312 , the loaded pallet  290  is moved away from the mold conveyor  40 , as described below, for loading onto transport rack “R”. As shown in FIG. 1, the transport rack “R” transports the loaded pallet  290  to a remote brick drying room “D” where the green bricks are heated and dried. 
     Mold Reconditioning Station 
     Referring to FIG. 12, with the pallet  290  removed, the mold section  190  is further indexed downstream through a mold reconditioning station including a washing chamber  332 , a drying chamber  334 , a misting chamber  336 , and a sand coating chamber  338 . In the washing chamber  332 , two pairs of laterally-spaced oscillating water spray nozzles  340  and  342  cooperate to clean the interior surfaces of all mold cavities  188 . The first pair of nozzles  340  produces a high-pressure water spray sufficient to remove a majority of clay residue adhering to the interior walls of the mold cavities  188 . The second pair of nozzles  342  provides a final rinse to remove any remaining reside. In the drying chamber  334 , two pairs of laterally-spaced oscillating dryer vents  344  and  346  cooperate to dry the interior surfaces of all mold cavities  188 . Preferably, oscillation of the spray nozzles  340 ,  342  and dryer vents  344 ,  346  of each respective pair is controlled by a single drive cylinder  348  and drive rod  350 . In the misting chamber  336 , laterally-spaced low pressure misting nozzles  352  (only one shown) operate to apply a carefully controlled volume of water to all interior surfaces of the mold cavities  188 . In the sand coating chamber  338 , a chamber housing  354  contains dry sand which is agitated by paddles  356  to create an atmosphere of sand particles. Fan blades  358  positioned within the housing  354  create air streams entraining the sand particles and directing them towards the water-misted mold cavities  188 . A protective grid plate  360  is preferably attached to the chamber housing  354  to control and further direct the flow of dust particles. The paddles  356  and fan blades  358  are powered by a drive chain  362  and motor  364 . After sand coating, the mold section  190  passes over a laterally-extending surface brush  366  which removes any excess sand from outside the mold cavities  188 . At this point, the mold section  190  is fully processed and ready for movement back into the filling station to receive another batch of clay slugs. 
     Processing Green Bricks and Pallets 
     As shown in FIGS. 1,  18  and  19 , from the elevator assembly  312  of the brick ejector station, the loaded pallet  290  is transferred to the load end of the chain conveyor “C1”. The chain conveyor “C1” is mounted on support frame  368 , and moves in the direction indicated by arrow  370 . The chain conveyor “C1” includes laterally spaced pallet chains  372  attached to respective pairs of idler sprocket wheels  374  and guide rails  376 . The pallet chains  372  are operatively connected to a lateral drive shaft  378  actuated by motor  380 , drive chain  382 , and drive sprocket wheel  384 . 
     A pallet shuttle  400 , shown in FIGS. 20-22, is mounted on base frame  402  at the discharge end of the chain conveyor “C1” and includes a pair of spaced transfer arms  404  adapted for movement in both a vertical and horizontal direction in order to lift and remove the eight loaded pallets  290  from the chain conveyor “C1”. The transfer arms  404  are moved vertically by cooperating pairs of gear racks  406 , bearing rails  408 , linear bearings  410 , drive chains  412 , and sprocket wheels  414 . The sprocket wheels  414  are attached to opposing ends of a drive shaft  416  actuated by drive motor  418 . Horizontal movement of the transfer arms  404  is effected by cooperating pairs of gear racks  420 , bearing rails  422 , linear bearings  424 , drive chains  426 , and sprocket wheels  428 . The sprocket wheels  428  are attached to opposing ends of a drive shaft  430  actuated by drive motor  432 . 
     The pallet shuttle  400  lifts and transfers the loaded pallets  290  from the chain conveyor “C1” to an elevator  440 , shown in FIGS. 23-26. Upon horizontal movement away from the chain conveyor “C1”, the transfer arms  404  of the shuttle  400  lower vertically to place the pallets  290  onto a pair of spaced elevator placement arms  442 . The elevator placement arms  442  are adapted for both horizontal and vertical movement in order to insert the loaded pallets  290  into the pallet transport rack “R”. The elevator placement arms  442  are moved vertically by cooperating pairs of gear racks  444 , bearing rails  446 , linear bearings  448 , drive chains  450 , and sprocket wheels  452 . The sprocket wheels  452  are attached to opposing ends of a drive shaft  454  actuated by drive motor  456 . Horizontal movement of the transfer arms  442  is effected by cooperating pairs of gear racks  458 , bearing rails  460 , linear bearings  462 , drive chains  464 , and sprocket wheels  466 . The sprocket wheels  466  are attached to opposing ends of a drive shaft  468  actuated by drive motor  470 . After the pallet transport rack “R” is filled, it is moved to the drying room “D” where the green bricks are dried. 
     From the drying room “D”, the loaded pallets  290  are transferred on transport racks “R” to the brick stripper station  60 , shown in FIGS. 1,  27 , and  28 . The pallets  290  are unloaded from the pallet transport rack “R” by reverse operation of an elevator and shuttle, identical to those previously described. The elevator and shuttle cooperate to load the pallets  290  onto a conveyor “C2” to a cylinder-driven index assembly  470  the brick stripper station  60 . In the brick stripper station  60 , the loaded pallets  290  are moved downstream where the dried bricks engage a stripper arm  482 . The stripper arm  482  is powered by cooperating air cylinders  484  and  486  which actuate causing the stripper arm  482  to push the dried bricks off the pallet  290  and onto a brick transport conveyor  487  to the oven “O”. A magnetic pallet spotter  490  including a carrier frame  492 , a magnetic shuttle plate  494 , a hanger frame  496 , and bipolar magnet  498  engages the empty metal pallets  290  and delivers the pallets  290  to conveyor “C3” (See FIG.  1 ). A rodless air cylinder  500 , bearing rail  502 , and linear bearing  504  cooperate to move the pallet spotter  490  horizontally, while air cylinder  508  enables vertical movement. Conveyor “C3” moves the empty pallets  290  downstream to a shuttle and elevator which cooperate, as previously described, to load the pallets  290  into transport racks “R” for transport to the pallet storage area “S”. 
     Referring to FIGS. 1,  29 ,  30 , and  31 , from the pallet storage area “S”, the transport racks “R” are moved in sequence to the loading end of chain conveyor “C4”. An elevator and shuttle, identical to those previously described, remove the empty pallets  290  from the transport rack “R” and position the pallets  290  onto the chain conveyor “C4”. The chain conveyor “C4” moves the pallets  290  downstream to a stop guide  518  located at an opposite discharge end of the chain conveyor “C4”, as shown in FIG.  29 . Pallets  290  accumulate at the discharge end of the chain conveyor “C4” and are indexed by a rocker arm  520 , index plate  522 , and index cylinder  524  in a preferred group of eight pallets  290 . Laterally-spaced alignment rails  526  cooperate to align the pallets  290  and deliver the pallets  290  to the inversion station  80  one at a time. The inversion station  80 , shown in FIGS. 30 and 31, includes a support frame  532 , guide rollers  534 , and roller conveyors  536 . The roller conveyors  536  are carried on a rotating inversion wheel  538  actuated by a drive shaft pulley  540  operatively attached to a drive motor  542  and drive chain  544 . The inversion wheel  538  rotates counterclockwise to invert and deliver the empty pallet  290  onto a horizontal pallet conveyor assembly  550 . The horizontal pallet conveyor assembly  550  is mounted on a base frame  552  and includes a roller conveyor  554  with guide wheels  556  and opposing conveyor chains  558 . A drive motor  560  cooperates with drive chain  562  to actuate conveyor chain sprocket wheels  564  operatively attached to the conveyor chains  558 . The conveyor chains  558  move the empty pallets  290  to a magnetic pallet spotter  570 . The magnetic pallet spotter  570  includes bipolar magnets  572  and  574  which engage the metal pallets  290  on the horizontal pallet conveyor assembly  550 , and transfer the pallets  290  horizontally as indicated by direction arrow  576  to the mold conveyor  40 . When properly positioned in registration over the open mold section  190 , the magnets  572 ,  574  release the pallet  290  onto the mold section  190 . The pallet  290  is then clamped to the mold section  190  of the mold conveyor  40 , as previously described. 
     A brick molding apparatus and method are described above. Various details of the invention may be changed without departing from its scope. Furthermore, the foregoing description of the preferred embodiment of the invention and the best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation—the invention being defined by the claims.