Abstract:
A device is provided for unloading a mold from the mold support surface of a concrete products producing machine and moving it to a remote mold replacement station, and then loading a replacement mold to the support surface of the machine. It incorporates a carriage supporting framework, a mold carriage transport system on the framework extending into the molding machine from the mold replacement station, which is mounted by the framework for vertical travel, and a mold transport carriage for moving from the replacement station along the transport system to a position juxtaposed vertically with the machine mold support surface. An actuatable mechanism interacts with the transport system for moving the transport system vertically relative to the carriage supporting framework from a remote support position aligned vertically with the mold to a mold support position in which the transport system can move the mold out of the machine.

Description:
This invention relates to mechanical mold insertion and removal methods and machinery to be used conjunctively with concrete products molding machines to facilitate the changing of concrete product molds. The application relates to apparatus and methods disclosed in provisional application 60/014,044, filed Mar. 25, 1996 whose priority is claimed for the present application. 
    
    
     BACKGROUND OF THE INVENTION 
     Typically, concrete products machinery operators have struggled with moving the relatively heavy vibratable molds for making concrete blocks and other concrete products into and out of the molding machine. While in the past, mold changes were effected perhaps only once a week, or once a month, today concrete products producers operate high speed concrete products molding machinery which must make a variety of products and require a number of mold changes in a single work shift. The lift capacity of overhead crane machinery for carrying such molds must be in the 4,000 pound neighborhood with the present large molding machines being used by concrete products producers which utilize partitioned molds making a number of products at a time. 
     SUMMARY OF THE INVENTION 
     The mold insertion assembly which is incorporated with an appropriate conventional concrete products molding machine includes a pair of spaced apart left hand and right hand frames mounting carriage tracks along which simultaneously operating mold carriages are movable from an external position to an interior position in which they position the mold they carry on the throat plates of the molding machine. Mechanically operated cam mechanisms are provided for lowering the tracks and carriages simultaneously to deposit the mold on the machine&#39;s throat support surfaces and to raise it from the throat support surfaces so that it can be moved out of the molding machine. 
     One of the prime objects of the present invention is to design a mold insertion assembly for use on large, high production concrete product molding machines which makes it relatively physically easy for an operator to make mold changes. 
     Still another object of the invention is to provide apparatus of the character described which greatly shortens the time required to make mold changes and, thus, speeds up the production process. 
     Still a further object of the invention is to provide a simplified mold insertion apparatus incorporating tracks which can be relatively simply raised or lowered by cam plates which raise or lower the mold carriage tracks. 
     Still a further object of the invention is to provide a durable and reliable mold insertion apparatus which marries easily to existing concrete products molding machinery, on either a retrofit basis or as a part of newly manufactured molding machines. 
     Another object of the invention is to provide a mold insertion assembly which is capable of lifting and carefully lowering the heavy loads which are carried, and yet can be relatively inexpensively manufactured and sold at an economically attractive price. 
     Other objects and advantages of the invention will become apparent with reference to the accompanying drawings and the accompanying descriptive matter. 
    
    
     THE DRAWINGS 
     The presently preferred embodiment of the invention is disclosed in the following description and in the accompanying drawings, wherein: 
     FIG. 1 is a side elevational view of one of the carrier and track assemblies of the mold insertion assembly, with the carriage and track illustrated in lowermost position; 
     FIG. 2 is a top plan view thereof; 
     FIG. 3 is an end elevational view thereof; 
     FIG. 4 is a front elevational view of a typical contemporary concrete products molding machine with the right and left hand elements of the mold insertion assembly shown conjunctively therewith; 
     FIG. 5 is a side elevational view of the concrete products molding machine showing the mold insertion assembly supporting a typical replacement mold in ann &#34;out&#34; position ready to be loaded to the machine; 
     FIG. 6 is a similar view with the mold shown interiorly disposed in lowered position on the concrete products mold supporting throat surfaces; 
     FIG. 7 is a fragmentary schematic side elevational view illustrating the insertion apparatus and one of the mold throat plates particularly; 
     FIG. 8 is a schematic end elevational view illustrating only some of the parts shown in FIG. 7; and 
     FIG. 9 schematically illustrates a portion of an electrical circuit for operating the control cylinders. 
    
    
     DETAILED DESCRIPTION 
     Referring now more particularly to the accompanying drawings, it is to be understood, first of all, that the concrete products molding machine, generally designated 10, is illustrated only as being typical of this type of machinery and will not be described in any detail because the detail of the molding machine forms no part of the present invention. Mold insertion devices of the character to be described are available for the concrete products machines manufactured by Besser Company of Alpena, Mich. as the V3 -12, Dynapac, and Ultrapac machines, all of which are in the marketplace and are known to the many companies worldwide which own them. The various elements of such machinery, in a broad or general sense, are disclosed in the present assignee&#39;s U.S. Pat. Nos. 4,235,580 and 4,312,242 which disclose a vibratory mold assembly of the type which is contemplated to be inserted. U.S. Pat. No. 4,941,813 discloses a mold support assembly for one of applicants&#39;assignees machines. All of these patents are incorporated herein by reference for an understanding of the general environment in which the mold insertion assembly is operable. The machine in U.S. Pat. No. 4,235,580 incorporates forwardly projecting arms which are notched to provide throats with flat horizontal support surfaces and it is upon these mold support surfaces that the open top and open bottom molds utilized are supported. 
     In the present instance, the frame F of the molding machine 10 (see FIGS. 7 and 8 particularly) incorporates a frame bed 11 and side walls, plates or frames 12. The plates 12 include or support a pair of outwardly projecting frame throat plates 13 with projecting arms having mold support surfaces 13a providing the throat surfaces on which the mold, generally designated M, is to rest when it is moved interiorly into the machine 10 and lowered. Positioned within or transversely between the throat plates 13 are the carriage tracks 14 of each of a pair of mechanically discrete laterally spaced apart right and left hand carriage and track assemblies, generally designated R-MID and L-MID, to denominate respectively a right hand mold insertion device and a left hand mold insertion device. The devices R-MID and L-MID together constitute a mold insertion assembly generally designated MID. Either of the tracks 14 of the devices R-MID or L-MID, or both of them together may be termed a transport system having an interior portion interiorly in general vertical alignment with said mold support surface and an exterior portion extending outside the machine therefrom generally to the vicinity of a mold replacement station. 
     As FIG. 1 particularly shows, each of the tracks 14 supports a mold carriage, generally designated 15, which travels along its track 14 from the exterior position or mold replacement station MRS shown in FIG. 5 to the interior position shown in FIG. 6. Each carriage 15 has a plurality of sidewall openings or bores 16 for selectively positioning and securing a pusher member 17, with a pusher plate 17a, which is carried by the carriage 15 in any one of a number of longitudinally adjusted positions, depending on the size of the mold M being transported. Each carriage 15 may be aptly termed a carriage assembly or both considered together may be so identified. The right hand mold insertion assembly R-MID and left hand mold insertion assembly L-MID operate conjunctively to transfer the mold M which spans them, and are mirror image identical in configuration , one being a right hand machine and the other a left hand machine. It will, therefore, be sufficient to describe only one of them, as it is particularly disclosed in FIGS. 1-3. 
     In FIG. 1, it is to be noted that the track 14 is supported for vertical movement on a separate framework base plate or support frame 18 which is provided for each device or mechanism R-MID or L-MID, and which has leg openings or bores 18a permitting its positioning attachment to the throat plates 13 or other frame supports on the molding machine. The respective frames or frame sections 18 function as forwardly projecting extensions of the molding machine frame F. As FIGS. 2 and 3 particularly indicate, the carriage 15 is comprised of parallel side wall portions 15a, mounting and connected by transverse bearing pins 15b (FIG. 1) which carry carriage-supporting guide roller members 15c for easing travel of the carriage along the upper surface of track 14. The carriage walls 15a, which are also connected at their front ends by a block 15e, may be considered to define an inverted channel which extends downwardly to embrace the sides of track 14 and rotatably mount side guide rollers 15d which travel along the sides of the track 14 and transversely maintain the position of the rolling carriage 15 thereon. Rollers 15d are mounted on schematically indicated vertical pins 15f carried by the side walls 15a. The track 14 incorporates a vertically movable member or part 19 which supports the track 14 from the base plate or frame 18 in a manner which shortly will be described. The tracks 14 and parts 19 of each device R-MID and L-MID can be aptly considered components of a mold carriage support transport system. 
     At the upper and lower ends of frame 18, bearings 20 support shafts 21 for flanged rollers 22 which horizontally guide an intermediate cam plate or subframe 23 (between member 19 and frame 18) which has cam slots or grooves 24 therein. Mounted in the cam slots 24 are flanged cam follower rollers 26 which are supported on shafts 25 carried by bearings 26a provided on the track supporting member 19. Cam plate 23 has a dependant neck portion 23a which pivotally connects at its lower end, as with clevis pin 23b, to the clevised end of the piston rod 28 of a conventional double acting, solenoid energized, preferably air operated, actuator cylinder or motor 29 which is connected at its opposite end at 29a to a strap 30 carried by the frame 18. The cam plates 23 and cylinders 29 of either, or both, devices R-MID and L-MID may be considered to constitute actuatable mechanism for interacting with the mold carriage transport system. 
     As FIGS. 1 and 2 particularly show, a series of vertically spaced track bearing guides 31, 32, 33, and 34 are provided at each end of plate 18 for a pair of vertically disposed guide posts 35 which are carried by the base plate 18. The bearings 32 and 33 bolt to the track plate support member 19 and guide its vertical travel along posts 35. 
     In FIG. 9 a schematic electrical control circuit for each of the cylinders 29 incorporates a retract solenoid 36 and an extend solenoid 37. Switches 38 and 39 are provided for simultaneously energizing the solenoids of each cylinder 29, which can be push button or otherwise closed and opened. The details of the control circuit are not critical or novel and form no part of the present invention. 
     FIGS. 4-6 show a typical conventional mold M which includes compartments within which the concrete mix is molded in the usual manner. This partitioned mold M, for simultaneously forming a plurality of products, has spaced apart, vertically extending mold frame or side bar members 40 depending from the usual laterally projecting mold top plate frame 41 which is received on the throat surfaces 13a when the mold M is lowered. The frame side bars 40, which transmit vibratory motion to the mold cavities, support the vibrator shaft bearings 42 for the pair of vibratory shafts housed in shaft assembly housings 43. The drive sheave assemblies for driving each of the vibratory shafts are shown at 44 and it is these sheave assemblies 44 and the opposite bearings 42 which are supported on the carriages 15 adjacent the pusher members 17 of the mold insertion device MID so that the weight of the mold M is borne by carriages 15. 
     As is well known, once the mold M is in position in the machine, it is supported in a manner which permits it to be lifted off the throat supports 13a by a pallet support and supply assembly 48 during normal operation of the molding machine to permit the vibrator shafts to vibrate the mold M, thereby effecting even distribution and compaction of the moldable concrete material throughout the mold. The chute or concrete mix supplying element C for filling the mold in the first place is shown in FIGS. 5 and 6 in an interior position, but is movable in the usual manner to a position directly above the inserted mold M to charge the mold with the concrete mix. 
     During the time that the vibrators shafts are operating, there is a stripper head frame assembly 46 which is lowered by its drive so as to cause the stripper heads 47 to enter the mold to the level permitted by stop members. Upon engagement of the stripper head with the stop members, vibration of the mold M is discontinued and it is customary then to strip the molded product or products from the mold, immediately following the termination of vibration, by simultaneously effecting downward movement of the stripper head assembly 46 and the pallet support assembly 48 which has been moved upwardly in the first place to clamp the pallet 49 to the bottom of the mold M. 
     THE OPERATION 
     With particular reference to FIG. 5, it will be assumed that a mold or mold assembly M which is to be initially loaded to a &#34;mold empty&#34;molding machine has been placed on the left and right hand carriages 15 at the mold replacement station MRS with its pulley assemblies 44 adjacent the pusher parts 17. Typically, an overhead crane or the like will be used to transfer the mold M from a mold storage station to a position spanning the pair of carriages 15. In this loaded position, the mold rests on the vibrator sheaves 44 and the vibrator bearings 42 of the carriages 15. With the tracks 14 and carriages 15 in a raised position in which the cam rollers 26 are in the uppermost rear ends of cam slots 24, the operator can easily manually roll the carriages 15 inwardly by pushing on the mold M until the mold assembly M is received in vertically centered position with respect to the molding machine slide shaft S, slightly above the throat support surfaces 13a. The members 41, 42, and 44 will be received between the pair of throat plates 13. 
     Once the mold assembly M is in mold depositing position, the cylinders 29 are simultaneously activated to return the piston rod 28 of each L-MID and R-MID from right to left in FIG. 1 and move the cam plates 23 and slots 24 from right to left. This allows the track plates 19 to lower and the mold bearing carriages 15 to thereby also lower linearly. The lowering action will cause the mold M plate 41 to be deposited in a rest position on the throat support surfaces 13a, while carriages 15 continue to lower slightly to clear the mold. The empty mold carriages 15 then can be easily rolled manually outwardly to the (FIG. 5) mold replacement station position. 
     To change the mold M, it is simply necessary to move the lowered carriages 15 to a position below mold M. After that, the pneumatic cylinders 29 are simultaneously activated to raise the tracks 14 and carriages 15 to engage the underside of mold assembly M once again and raise it off throat support surfaces 13. It is then relatively easy to manually roll the loaded carriages 15 outwardly to the position shown in FIG. 5. There the mold M shown can be removed from carriages 15 and transported to the mold storage station, and a replacement mold M can be substituted for reinsertion purposes. 
     It is to be understood that other embodiments of the invention which accomplish the same function are incorporated herein within the scope of any ultimately allowed patent claims.