US2075591A - Expansible and contractible mold core - Google Patents

Description

March 30, 1937. T. SCHUSTER EXPANSIBLE AND CONTRACTIBLE MOLD CORE Filed Aug. 19, 1936 2 Sheets-Sheet l Elma/rm March 30, 1937. T. SCHUSTER EXPANSIBLE AND CONTRACTIBLE MOLD CORE Filed Aug. 19, 1956 2 Sheets-Sheet 2 I 0 w w v 7 w Wm w w THOMAS SCI/U6 715/;

Patented Mar. 30, 1937 UNITED STATES PATENT OFFICE Thomas Schuster, Phoenix, Ariz. Application August 19, 1936, Serial No. 96,876

7 Claims.

This application relates to a new and improved core for concrete molds, said core being similar to the core disclosed in my U. S. Patent No. 2,032,637, but not claimed therein, due to a requirement for 5 division between mold claims and core claims. It is the object of the invention to provide a rather simple and inexpensive core provided with novel means for expanding it into operative relation with a surrounding mold wall, and for contracting it for removal from the molded article. While the core is intended primarily for use in the molding of concrete boxes for housing underground meters, and is therefore usually of rectangular form, it is to be understood that the invention is not restricted to any particular field of use nor to only one shape. It may be constructed in various shapes on the contrary and used for the formation of numerous kinds of articles.

Figure 1 of the accompanying drawings is a top plan view of a rectangular core constructed in accordance with the invention.

Fig. 2 is a central vertical longitudinal sectional view on line 2-2 of Fig. 1.

Fig. 3 is a fragmentary end elevation.

Fig. 4 is a vertical transverse sectional view on line 4-4 of Fig. 1.

Fig. 5 is a detail perspective view.

Fig. 6 is a top plan view showing a core of cylinfl drical form.

Fig. 7 is a fragmentary perspective view more clearly illustrating the parts shown in Fig. 3.

The rectangular core illustrated in Figs. 1 to 5 includes two vertical side walls 68 and four end 1 wall sections 69, there being one of these end wall sections integrally joined to each end of each side wall 68. The inner edges of the end wall sections 69 are provided with integral vertical flanges 10 which project to the interior of the core, 40 said flanges diverging toward the center of said core as shown. Two upper and two lower longitudinal springs 1| and 12 respectively extend horizontally between the end wall sections 69 and are secured by suitable fasteners 13 to the remote 45 sides of the flanges 10. The central portions of these springs are secured to transverse plates or other tie members 14. The springs are preferably of the type commonly used on vehicles and they are employed to contract the core. When 50 the core is in contracted position, the springs are bowed away from each other to a greater extent than when the two halves of the core are spread apart to their operative positions. In moving from normal bowed form to less bowed form, the 55 straight distances between the ends of both I springs 1| and 12 to contract the core.

springs, lengthen, causing said springs to exert an outward pressure upon the end wall sections 69, springing these end wall sections outwardly to some extent. After molding of the article, when the springs 1| and 12 are permitted to return to 5 normal and contract the core for removal, said springs in moving back to their normal bowed positions, inwardly spring the end wall sections 69 to a slight extent from the aforesaid article,

facilitating removal of the core without injuring 10 said article.

For spreading the two halves of the core to operative position, I provide wedges 15 between the adjacent flanges 10, and operating means for said wedges, said operating means being mounted 15 upon the tie members 14. In the present showing, a vertical manually rotatable screw 16 is rotatable in bearing openings in the tie members collar 80 with the lower ends of said wedges.

The links may be of extensible and retractable 25 nature if desired, turnbuckles 83 being shown for varying their lengths. When the screw 16 is turned in one direction, the nuts or collars 19 and 80 are moved toward each other, thereby inwardly sliding the wedges 15 and allowing the When screw 16 is tlurned in the other direction, the

' collars or nuts 19 and 80 are moved away from each other, causing the links 8| and 82 to outwardly force the wedges 15, expanding the core to its operative position. The outward movement of the wedges 15 is limited by lateral lugs 84 on the ends of said wedges, which lugs strike the edges 85 of notches 8B in the inner edges of the flanges 10. During adjustment of the wedges 40 15, the lugs 84 move in and are guided by the notches 86. By having the lugs 84 abut the edges 85, outward pressure on the end wall sections 69, in addition to the pressure exerted by the springs 1| and 12, is provided.

In Fig. 6, the side Walls 68 and end wall sections 69 so merge into each other as to jointly form a circular core designed primarily for molding concrete pipes, cylindrical meter box walls, or the like. Springs 1| of slightly different form from the springs above described, are connected with the flanges 10' and are secured at their intermediate portions to tie members 14' upon which the screw 16 is mounted 55 in use, the lugs 81 rest upon a suitable pallet (not shown) upon which the mold wall and core are also supported. This pallet may be of the general form shown in the aforesaid Patent No. 2,032,637.

It will be seen from the foregoing that novel I and advantageous provision has been made for carrying out the objects of the invention, and while the details disclosed may be considered as preferred, variations as to size, shape, proportions, and structural details, may be made within the scope of the invention as claimed.

I claim:--

1. A core comprising side walls and end wall sections joined thereto, vertical wedges between said end wall sections for expanding said core, two upper and two lower longitudinal springs connected at their ends with said end wall sections for contracting the mold, an upper and a lower transverse tie member extending between said upper springs and said lower springs respectively and secured to the central portions thereof, and means mounted on saidtie members and connected with said wedges for operating the latter.

2. A core comprising side walls and end wall sections joined thereto, the inner ends of said .end wall sections being provided with diverging vertical flanges projecting from the inner sides of said sections, twoupper and two lower longitudinal springs secured at their ends to said flanges for contracting the core, an upper and a lower transverse tie member extending between said upper and said lower springs respectively and secured to the intermediate portions thereof, vertical wedges between the aforesaid flanges for expanding the core, and means mounted on said tie members and connected with said wedges for operating the latter.

3. A core comprising two side walls, end wall sections connected with the ends of said side walls, laterally spaced longitudinal springs connected at their ends with said end wall sections for contracting the core, means connecting the central portions of said springs with each other, and means for forcing said end wall sections away from each other in directions transverse to the side walls, said springs being bowed away from each other to cause said springs to outwardly force said end wall sections in directions parallel with said side walls when said end wall sections are forced in the first mentioned directions.

4. A core comprising side walls and end wall sections yieldably joined thereto, the inner ends of said end wall sections being provided with diverging flanges projecting inwardly from the inner sides of said sections, wedges between said flanges, means for forcing said wedges away from each other to cause them to wedge said flanges apart and expand the core laterally, and

means on said wedges to abut the inner edges of said flanges and force outwardly thereon to expand the core longitudinally.

5. A core comprising side walls and end wall sections yieldably joined thereto, the inner ends of said end wall sections being provided with diverging flanges projecting inwardly from the inner sides of said sections, wedges between said flanges, means for forcing said wedges away from each other to cause them to wedge said flanges apart and expand the core laterally, and lateral lugs on said wedges to abut said flanges and force outwardly thereon to expand the core longitudinally, said flanges having notches receiving said lugs to guide the wedges during adjustment.

6. An expansible core having two wall sections in substantially edge-to-edge relation, means for expanding the core and separating said wall sections, laterally projecting lugs on the adjacent edges of said wall sections, and an arched strip straddling said lugs to form an opening through the material to be molded around the core.

'7. A core having wall sections, leaf or similar springs connected with said wall sections and holding them yieldably in predetermined relation, said springs extending across the interior of the core, tie members to which the central portions of said springs are secured, wedges bea tween said wall sections for spreading the same,

and means mounted on said tie members for actuatingsaid Wedges.

THOMAS SCHUSTER.

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