US3348802A - Mold box - Google Patents

Description

Oct. 24, 1967 R. B. CORBETT 3,348,802

MOLD BOX Filed Sept. 22, 1965 2 Sheets-Sheet l lNvENToR Robert B. Corbett Oct. 24, 1967 R. B. coRBETT MOLD BOX 2 Sheets-Sheet 2 Filed Sept. 22, 1965 INVENTOR Reben` B. Corbett United States Patent() 3,348,802 MOLD BOX Robert Corbett, Mars, Pa., assignor of one-half each to Sam Heppenstall & Associates, Inc., and Corbett AS- sociates, Inc., both corporations of Pennsylvania Filed Sept. 22, 1965, Ser. No. 489,326 Claims. (Cl. 249-163) The present invention relates to mold -boxes of the collapsible variety, and more particularly to a mold box of the character described adapted for molding concrete blocks, test samples or the like.

Concrete molds and the problems appertinent have long been known in the art. Such molds were usually fabricated from either various types of wood or from steel, to which the concrete would readily adhere. In the case of wood, the opened grained structure thereof presented a porous surface into which the iiner particles of the concrete tended to flow and thereby to bond with the surface in a manner akin to a knitting action. Therefore, it was diicult if not impossible, to remove the wooden mold portions without marring the surfaces of the concrete or of the mold. In the case of steel molds, the iron would tend to rust and form oxide coatings which would knit with the oxides of the cement used in the concrete, with the result that the concrete would adhere rather strongly to the steel mold. Thus, removal of the steel mold was diicult and usually carried with it surface portions of the concrete casting resulting in an inferior surface condition. Plating the steel mold surfaces alleviated the problem to some extent, until the removal of the plating by the abrasive character of the concrete again presented the rust problem of the exposed steel surfaces.

Another problem in this area has been the lack of a concrete mold or the like, from which the concrete block or casting can be quickly and easily removed without damage to the casting in its still green condition. This problem is aggravated by the fact that the considerable weight of the concrete or other material being cast tends to spring the side wall portions of the mold outwardly, which makes removal of the side walls dii'licult, in the case of a collapsible mold structure, in addition to causing dimensional distortion of the concrete casting. To combat this tendancy of the side walls to distort in this fashion, various fastening means and braces have been employed therewith, which however, become embedded slightly in the concrete, so that removal of the casting from the mold becomes ditiicult in addition to presenting an undesirable surface contour. Unfortunately, when the sides of the mold were distorted in this fashion, leaks developed, causing undesirable loss of water from the concrete mixture and in extreme cases, losses of water and of the concrete aggregate also. In this connection, no adequate means was provided in previous concrete mold structures for preventing leaks therefrom even in the absence of mold distortion. This problem fas particularly diii'icult in the case of collapsible, re-usable mold structures, as no adequate means were provided for properly clamping the parts together in a leak proof manner.

The foregoing difficulties were aggravated still further in the case of light-weight portable mold structures of the collapsible variety. The latter mold structures find extensive use in making test samples of concrete or it is being poured in highway or building construction and in similar applications where it is important to ascertain the resultant strength of the poured concrete after it has cured. Such test samples must be of uniform size and of good surface characteristics for proper comparison with standard sarnples or data obtained therefrom. It is also imperative that the mold structure admit of facile assembly and disassembly to minimize the time required for making the test samples and be of compact construction to facilitate its portability between pours or between jobs, as the case may be.

These problems are solved by the present invention which provides a collapsible mold box for concrete or the like, with a novel clamping means for vsecuring the sides and end wall components of the mold together in a closely fitting, substantially leak-proof manner and at the same time for clamping the assembly thus formed to a bottom wall component of the mold box in a similarly closely fitting, substantially leak-proof manner. With this arrangement, an essentially leak-proof mold structure is provided, which ensures, in the case of concrete casting,

that little or no loss of the measured water added to the aggregate will be lost before the concrete can set up.

Additionally, the novel mold structure includes a unique reinforcement means for the several wall components mentioned above which are arranged on the outside of the mold structure, i.e., away from the internal surfaces of the mold which engaged the charge of material poured therein. Where such reinforcing means cooperatively engaged two or more of the wall components for assembly thereof as well as for reinforcement, such engagement is arranged so as not to interfere with the substantially leakproof character of the junctions lbetween the wall components.

In accordance with another feature of the novel mold structure, means are associated with the aforementioned clamping means and are operable to aid in removing the clamping means and the wall component or components secured thereto from the mold structure when it is desired to remove the molded material, such as the aforementioned concrete casting, therefrom.

Other features of the invention provide a particular arrangement of reinforcing means whereby the aforementioned wall components can be readily assembled and disassembled in order to utilize most fully the collapsible character of the mold structure. It is also contemplated in certain arrangements of the mold structure, or for certain applications thereof such as for concrete casting, that 'the component parts thereof can be fabricated from a structural material such as stainless steel to which the aforementioned concrete will not strongly adhere. The absence of rust formation on the stainless steel components, when used, obviate the tendency of the concrete surfaces to knit with the adjacent surfaces of the mold structure, which will occur where rusted or other oxide coated mold surfaces are employed, as noted previously.

These and other objects, features, and advantages of the invention, together with structural details thereof, will be elaborated upon during the forthcoming description of certain preferred embodiments of the invention, together with presently preferred methods of practicing the same.

In the accompanying drawings, I have .shown certain presently preferred embodiments of the invention and have illustrated presently preferred methods of practicing the same, wherein:

FIGURE l is a top, end, and right side isometric View of one form of mold structure arranged in accordance with the invention; v

FIGURE 2 is a top and end isometric view of the mold structure illustrated in FIGURE 1 and showing the side walls thereof in semi-collapsed position;

FIGURE 3 is a cross-sectional view of the mold structure as shown in FIGURE 1, and taken along reference plane III-III thereof;

FIGURE 4 is a top, left side, and end isometric partial view, somewhat enlarged of the mold structure shown in FIGURES l and 2, with the end wall removed;

FIGURE 5 is atop, left side, and end isometric partial view of the mold structure shown in FIGURE 4 and illustrating the utilization of the clamp means and associated components for loosening parts of the mold structure after the completion f the casting operation; and

FIGURE 6 is a top, left side and end isometric partial view of the mold structure shown in FIGURES 4 and 5 with the end wall partially opened.

Referring now more particularly to the drawings, the illustrative form of the invention shown therein comprises a collapsible mold structure denoted generally by the reference character 10. The mold structure 10 includes a bottom wall member 12, as viewed in the drawings, which is reinforced in this arrangement of the invention by a pair of integrally formed depending flanges 14 extending longitudinally of the bottom wall member 12 at the lateral edge portions respectively thereof.

A pair of side wall members 16 and end wall members 18 are detachably joined to the bottom wall 12 and arranged thereon so as to form an open top, generally rectangular structure. The side Walls 16 and the end Walls 18 respectively are reinforced at their upper lateral edges by means of out-turned flanges 20 and-22 extending generally longitudinally of the side and end walls 16, 18.

The side and end walls 16, 18 are further reinforced adjacent their lower edge portions by quick-detachable joining means whereby the side and end walls are mounted on the bottom wall 12. .As seen in the drawings one form of quick-detachable joining means includes a plurality of depending tabs 24 secured on the outer surfaces of the side walls 16 and positioned adjacent the lower lateral edges thereof so as to extend downwardly thereof and into suitably placed slots 26 formed therefor in the bottom wall 12. To facilitate assembly of the mold structure, desirably the tabs 24 fit rather closely in their respective slots 26 so that the narrow slots and the thickness of the material comprising the tabs 24 and the bottom wall 12 produce a wedging action to maintain the side walls 16 in an intermediate collapsed position, as shown in FIGURE 2 of the drawings, when not otherwise secured to the mold structure 10. This arrangement permits pre-positioning of the side wall members to facilitate grasping and manipulating the same when assemblying the mold structure 10. The slots 26 are further aligned with the bottom edge 28 of the associated side wall 16 so as to align and reinforce the lower edge portion of the side wall 16 and to prevent bulging thereof when a charge of relatively heavy material such as concrete is poured into the mold. Although three such tabs 24 are illustrated, it will be obvious that a greater or lesser number can beremployed depending upon the length of the mold structure, the thickness and strength of structural materials from which the mold structure is fabricated, and the type and weight of charge poured into the mold structure.

In a similar manner, end walls 18 are provided with depending tabs 29 cooperative with appropriately bottom wall slots 30 for detachably securing the end walls 18 to the bottom wall 12 and for reinforcing the lower portions thereof.

As evident from the various figures, particularly FIG- URE 3, the positioning and reinforcing tabs 24, 29 and their slots 26, 30 are disposed outwardly of the junction between the side wall bottom edges 28 and the end wall bottom edges 32 so that the tabs 24, 29 will not contact the charge and mar the surface of the resulting casting, and so that the charge will not have access to the slots 26, 30 to leak therethrough from the mold structure. In -further prevention of leaks in the mold structure, the aforementioned bottom edges 28 and 32 of the side walls 16 and the end walls 18 respectively are made parallel to one another and otherwise disposed so as to lie in the same plane, and the upper or mold surface of the bottom wall 12 is likewise made planar and smooth as possible so as to produce a closely fitting, leak-tight junction between the side and end Walls 16, 18 and the aforementioned upper surface of the bottom wall 12 about the Ilower edge periphery of the vertical wall structure of the mold. As

described more fully below, clamping means are provided for maintaining the aforementioned closely fitting relationship between the bottom wall 12 and the normally vertical wall structure and also between the side walls 16 and the end walls 18 composing the vertical wall structure.

As shown in FIGURES l, 2, 5 and 6 of the drawings, the aforementioned clamping means, indicated generally by reference character 34, are associated with each of the end plates 18. In this arrangement, each clamping means 34 are provided with a T configuration including cross bar 36 and standard 38. The cross bar 36 thereof is mounted in a pair of spaced, slotted brackets 40 secured on the outer surface of the associated end plate 18 and disposed near the upper or anged edge thereof. The cross bar 36 when thus mounted is arranged for insertion of its end portions respectively into the adjacent L-shaped slots 42 formed in the adjacent ends of the elongated side walls 16. The longitudinal slots 44 in the normally vertical, cross-bar brackets 40 (FIGURES 1 and 5) are of sufficient length to allow the cross bar ends to be inserted into and downwardly of the L-shaped notches 42.

As better shown in FIGURE 6, the cross bar brackets 40 are spaced inwardly from the vertical edges respectively, of the associated endplate 18 so as not to interfere with drawing the adjacent surfaces of the side walls 16 tightly against the end wall vertical edges by tightening cross bar wing nuts 46, which threadedly engage the threaded end portions of the cross bar 36. In this example, the aforementioned end portions are formed by threading a pair of machine bolts 48 into drilled and tapped apertures extending axially a short distance into the ends of the cross bar 36. When thus secured, the heads of the machine bolts 48 prevent inadvertent unthreading and removal of the wing nuts 46. The notches 26 along each lateral edge of the bottom wall 12 are spaced transversely thereof such that when the side walls 16 are raised to their vertical positions against the end walls 18 the side wall tabs 24 urige the side walls into close fitting engagement thereof with a least the lower portions of the aforementioned end wall vertical edges, with the clamping engagement therebetween being completed, as described below, by the clamping means 34, and in particular by the cross bar 36 thereof and associated components.

As better shown in FIGURES 1 and 5 of the drawings, the end walls 18 are positioned inwardly of the adjacent ends of the side walls 16 so that the vertical edges thereof are displaced inwardly of the side wall notches 42. Desirably, the inward displacement of the end walls 18 is equal to the width of their top flanges 22 in order to lend a neat appearance to the mold structure and to minimize projecting corners and edges which may otherwise cause injury during use. In furtherance of this purpose, the outer corners of the side wall anges 20 are removed orv rounded off asfdenoted by reference characters 43.

When the side and end walls 16, 18 are assembled with the clamping means 34 and with the aid of the wall tabs 24 and 29 and cooperatively spaced slots 26 and 30 of the bottom wall member 12, the vertical wall assembly thus for-med can then be clamped against the bottom wall member in order to produce the aforementioned closefitting engagement therebetween for essentially leak proofing the mold structure 10. In furtherance of this purpose, the standard 38 of each clamping means 34 is moved to the vertical position as shown in FIGURE 1 such that the lower end thereof is inserted into a notch 50 in the associated end of the bottom wall 12. Standard wing nut 52, which is threaded upon the lower threaded end portion of the standard 38, is then tightened to complete the clamping engagement of the clamping means 34 with the bottom wall 12, whereby the lower peripheral edges 28, 32 of the vertical wall structure 16, 18 are compressed into engagement with the bottom wall member 12. Desirably,

the lower ends of the L-shaped notches 42 and of the cross bar slots 44 are mated on the same elevational plane so that the cross bars 36 engage both side walls 16 and the cross-bar brackets 40 of the associated end walls 18 to apply clamping force to all components 16, 18 of the vertical wall structure when the standard wing nuts 52 are tightened, without relying necessarily on the mere frictional engagement of the subsequently tightened cross bar wing nuts 46 with the side walls 16 respectively. Following this operation the cross bar wing nuts 46 are tightened to complete the clamping engagement of the clamping means 34.

Means are also contemplated by the invention for facilitating opening and loosening the mold components from the material cast therein. One arrangement of the lastmentioned means includes the provision of a slidably mounted impact member 54 on each of the clamping means 34. In this arrangement the impact member 54 is a heavy walled tubular member through the axial opening of which the standard 38 is inserted. The impact member 54 is retained on the standard 38 at the upper end by means of the cross bar 36 and at the lower end by the standard wing nut 52 and washer 56.

In order to loosen the vertical wall structure 16, 18 after the charge has solidied, or set up and/ or c-ured in the case of concrete, clamping means wing nuts 48, 52 are loosened and the clamping means standard 38 is angularly displaced outwardly from the Side wall a suicient -distance so that the impact member 54 can be grasped and slid forcefully against the cross bar 36 in order to apply impacting forces to the end walls 18 through cross bar 36 and .brackets 40. The impacting lforces thus delivered to the end walls 18 need not be large since the relatively non-adherent construction minimizes the adherent forces between the mold structure components and the concrete or other charge.

Although stainless steel is desirable structural material for the side and end walls 16, 18 and the bottom wall 12, in the case of concrete casting, it is to be understood that other suitable structural materials can be utilized depending upon the application of the invention. Those components of the mold structure 10, such as the clamping means 34, which do not Contact the charge can, of course, be constructed from ordinary structural materials without regard to the charge or material being cast in the mold structure. Thus, for example, the clamping means 34 can be fabricated from ordinary carbon steel.

In the operation of the invention, for assembling the mold structure the side walls 16 and the end walls 18 are disposed at outwardly ared angles, and their tabs 24 or 29 are inserted into the respective bottom wall slots 26, 30 (FIGURE 2). Each of the tabs 24 and 29 are bent outwardly as indicated `by reference characters S8 (FIGURE 3) to facilitate inserting the tabs 24, 29 in their slots. The outwardly bent tab portions 58 also serve to retain the vertical wall structure 16, 18 upon the 4bottom wall 12 when the side and end wall are otherwise secured in their vertical positions, in the event of inadvertent or premature loosening of the standard wing nuts 52 of the clamping means 34. For this purpose, the bottom wall slots 26 and 30 are suiciently narrow that the tabs 24 and 29 are prevented from verticalv withdrawal therefrom by engagement of the bent tab portions 58 with the adjacent outer edges of the slots.

After insertion of the side and end Walls, as depicted in FIGURE 2, the side walls 16 are then moved to their vertical positions as shown in FIGURE l and the end walls 18 are moved toward their vertical positions While at the same time the clamping means cross bars 36 are moved upwardly in their bracket slots 44 so that the threaded end portions thereof can be inserted into the L-shaped notches 42 of the side walls. The end walls are then positioned vertically whereupon the clamping means cross bars 36 drop to the bottoms of the notches 42 and the bracket slots 44. The clamping means 'are then pivoted about the axes of their cross bars 36 so that the lower ends of their standards 38 can be inserted into the bottom wall notches 50. The wing nuts 46, 52 of each clamping means are then tightened to secure the Wall components 16, 18, 12 together in the aforedescribed close tting, essentially leak-proof relationship. Desirably the standard wing nuts 52 are first tightened to ensure engagement of the entire lower edge periphery of the vertical wall structure 16, 18 with the adjacent bottom wall surfaces.

In order to remove a casting from the mold structure 10, the clamping means wing nuts 46, 52 are loosened and the clamping means standards 38 are pivoted outwardly at a convenient angle' to the end walls 18 so that the impact members 54 can ybe readily manipulated to deliver impacting forces to the end walls 18. Only a few blows are required to loosen the end plates 18 from the casting. If desired, the cross bar wing nuts46 can be retightened before impacting movements of the impact members 54, in order to ensure transmittal of the impact forces from the end walls 18 in order to transmit the impacting forces directly to the side walls 16 through the clamping engagement thereof with the end walls 18. The impacting forces also are transmitted to the bottom wall member 12 from the side and end walls 16, 18 by virtue of the side and end walls resting edgewise upon the bottom wall member.

Following this operation, the side and end walls 16, 18 can be moved to their semi-collapsed positions as shown in FIGURE 2, whereupon the casting can be lifted from the bottom wall 12.

From the foregoing it will be apparent that novel and eicient forms of mold structures have been disclosed herein. While I have shown and described certain presently preferred embodiments of the invention and have illustrated presently preferred methods of practicing the same, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.

I claim:

1. A mold structure comprising a bottom wall member, a plurality of vertical wall members detachably joined to said bottom wall member, a generally T shaped clamping member rotatably mounted on at least one of said vertical wall members, said one vertical wall member extending between a spaced opposed pair of said vertical wall members, and means for securing said clamping member to said opposed wall members and to said bottom wall member.

2. The combination according to claim 1 characterized in that each of said vertical wall mem-bers has a number of depending tabs secured thereto adjacent the bottom edge thereof, said tabs being inserted respectively into slots therefor in said bottom wall member.

3. The combination according to claim 2 characterized further in that the lower end portions of said tabs are bent from the plane of said tabs to prevent inadvertent removal of said vertical wall members from said bottom wall member when said vertical wall members are disposed normal to said bottom wall member.

4. The combination according to claim 2 characterized further in that said tabs and said slots are disposed outwardly of the junction between the bottom edges of said vlertical wall members to prevent leakage through said s ots.

5. The combination according to claim 1 characterized in that an impact member is slidably mounted upon said clamping member for movement in a direction therealong to deliver impacting forces to said one vertical Wall member.

6. A mold structure comprising an elongated bottom wall member, a pair of spaced opposed side wall mem- Ibers detachably secured to said bottom wall member, a pai-r of spaced opposed end wall members extending generally between said side wall members adjacent the ends thereof respectively said end wall members being detachably secured to said bottom Wall member, a generally T shaped clamping member rotatably mounted on each of said end walls, and means for detachably securing said clamping members to said side walls and to said bottom wall member.

7. The combination according to claim 6 characterized in that an impacting member is slidably mounted on each of said clamping members for movement therealong in a direction to deliver impacting blows to the associated one of said end walls.

8. The combination according to claim 6 characterized in that an upper cross bar of each of said clamping members is rotatably and slidably mounted adjacent the upper edge of each of said end walls for cooperation with L- shaped notches formed in the adjacent edge portions of said side Walls, and a standard for each of said clamping members extends from the cross bar thereof to said bottom wall member, said standards being angularly displaceable relative to said end walls respectively for in sertion of said standards into retaining notches therefor formed in the adjacent ends respectively of said bottom wall member, said securing means being operable when said cross bars and said standards are inserted into said side wall notches and said bottom wall notches respectively.

9. The combination according to claim 6 characterized in that reenforcing anges are extended along the lateral edges of said bottom wall member and along the upper edges of said side walls and said end walls respectively, said flanges being turned outwardly of the mold surfaces of said side and said end walls and of said bottom wall member.

10. The combination according to claim 8 characterized in that an impacting member is slidably mounted on each of said clamping member standards and that said standards are further displacea'ble outwardly of said end plates respectively so that impacting movements of said impact members along said standards and toward said end walls deliver impacting forces to said end Walls.

References Cited UNITED STATES PATENTS 799,493 9/ 1905 Pfeifer 249-163 X 2,928,259 3/1960 Mundie 249-165 X FOREIGN PATENTS 1,188,499 3/ 1965 Germany.

I. SPENCER OVERHOLSER, Primary Examiner.

HOWARD I. FLINT, JR., Examiner.

Claims (1)

1. A MOLD STRUCTURE COMPRISING A BOTTOM WALL MEMBER, A PLURALITY OF VERTICAL WALL MEMBERS DETACHABLY JOINED TO SAID BOTTOM WALL MEMBER, A GENERALLY T SHAPED CLAMPING MEMBER ROTATABLY MOUNTED ON AT LEAST ONE OF SAID VERTICAL WALL MEMBERS, SAID ONE VERTICAL WALL MEMBER EXTENDING BETWEEN A SPACED OPPOSED PAIR OF SAID VERTICAL WALL MEMBERS, AND MEANS FOR SECURING SAID CLAMPING MEMBER TO SAID OPPOSED WALL MEMBERS AND TO SAID BOTTOM WALL MEMBER.

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