Method and device for removal of items from a mold

Abstract

A method and device for removal of a molded sample from a mold with minimal or no damage to the molded sample. The device includes a drill configured for perforating a wall of the mold with the formation of a through aperture, a shroud passageway through or adjacent the drill, and a passageway from a source for pressurized fluid leading to the shroud passageway. The shroud passageway is configured whereby fluid such as air is applied therethrough simultaneously with perforation operation of the drill. Air directed through the aperture is pressurized and comes into effective contact with the molded sample whereby the molded sample is prevented from being more than minimally contacted with the drill and caused to be removed from the mold.

Claims

1. A device for causing removal of a molded sample from a mold container having a closed end, with minimal damage to the molded sample comprising: a) a drill separate from the mold container configured for perforating the closed end of the mold container with the formation of a through aperture, b) a surrounding shroud peripherally encircling the drill, which does not impede perforation operation by the drill, and c) a source for pressurized fluid, wherein the shroud is attached to the pressurized fluid source as a conduit whereby pressurized fluid is applied through the shroud and peripheral to the drill simultaneously with perforation operation of the drill and the pressurized fluid is directed through the aperture into direct contact with the molded sample whereby the molded sample is caused to be removed or separated from and made removable from the mold container by direct forceful contact with the pressurized fluid, with substantial minimization of the drill from contacting the molded sample.

2. The device of claim 1, wherein the molded sample is comprised of concrete for compression testing and wherein the pressurized fluid is air and the shroud is configured to withstand a pressure sufficient to remove the molded sample from the mold container.

3. A device for causing removal of a molded sample from a mold container having a closed end with minimal damage to the molded sample comprising: a) a drill configured for perforating the closed end of the mold container with the formation of a through aperture, b) a surrounding shroud peripherally encircling the drill, which does not impede perforation operation by the drill, and c) a source for pressurized fluid, wherein the shroud is attached to the pressurized fluid source as a conduit whereby pressurized fluid is applied through the shroud and peripheral to the drill simultaneously with perforation operation of the drill and directed through the aperture into direct contact with the molded sample whereby the molded sample is caused to be removed or separated from and made removable from the mold container with substantial prevention of the drill from contact with the molded sample, wherein the drill is fluted and is configured to comprise at least part of the fluid conduit shroud.

4. The device of claim 3, wherein the drill is perforated and is configured to comprise at least part of the conduit shroud, with inclusion of a longitudinal perforation to connect with the directed pressurized fluid to a perforating end of the drill.

5. The device of claim 1, wherein the drill comprises a flat surface in contact with the closed end of the mold container and wherein the flat surface comprises a protrusion which serves, with rotation, to effect the perforation of the closed end with the protrusion being of minimal height whereby it minimally contacts the mold sample after perforation of the closed end of the mold container.

6. The device of claim 5, wherein the protrusion is angled whereby the perforation permits an enhanced flow of fluid between the mold sample and the mold container.

7. The device of claim 1, wherein the conduit shroud comprises a lip which is configured to contact an outer surface of the closed end peripheral to the perforation to effect pressure retention of the pressurized fluid.

8. A method for removal of a molded sample from a mold container having a closed end with minimal damage to the molded sample comprising the steps of: a. providing a drill separate from the mold container for perforation of a base wall of the mold with a through aperture; b. encircling the drill with a conduit shroud whereby a pressurized fluid is able to be directed through the shroud and through the through aperture into contact with a base of the molded sample; c. simultaneously drilling and perforating the base wall and directing a pressurized fluid through the conduit shroud into direct contact with the base of the molded sample whereby the molded sample is moved away from contact with the drill after the base all of the mold is perforated, wherein the molded sample is comprised of concrete for compression testing and wherein the pressurized fluid is directed as air and the conduit shroud is configured to withstand a pressure sufficient to remove or dislodge the molded sample from the mold.

9. The method of claim 8, wherein the drill is provided with a flat surface in contact with the base wall of the mold and wherein the flat surface is further provided with a protrusion which serves, with rotation, to effect the perforation of the base wall.

10. The method of claim 9, wherein the provided protrusion is angled whereby the perforation perforates the base wall with an angle which permits an enhanced flow of fluid between the mold sample and the mold.

11. The method of claim 8, wherein the conduit shroud comprises a lip which is configured to contact an outer surface of the base wall peripheral to the perforation to effect pressure retention of the pressurized fluid.

12. The device of claim 1, wherein the drill is configured to rotationally perforate the closed end of the mold container.

Description

SHORT DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 depicts a typical concrete mold sample contained with a plastic mold receptacle;

(2) FIG. 2 depicts the mold sample of FIG. 1 as being inserted within a jig structure having the drill structure of the invention;

(3) FIG. 3 is an enlarged view of the drill bit with flat head as used in the drill structure;

(4) FIG. 4 is a side cross sectioned view of the operative portion of the drill structure with drill bit and air inlet and conduits (shroud or passageway elements); and

(5) FIG. 5, depicts the drill bit with mold base perforation and air pressure influx for sample movement relative to the mold receptacle.

DETAILED DESCRIPTION OF THE INVENTION AND DRAWINGS

(6) In a further embodiment, the drilling structure has a gas retention and directing enclosure (shroud or passageway) around the drill bit with an inlet for fluid and most commonly gas, such as air from a source. Alternatively, the drill bit has a drill tip with an integrated passageway. The air is directed through the shroud or passageway and into the mold interior, after wall perforation, where it becomes pressurized under the pent up conditions. Pressurization is not necessarily required and the air is not necessarily even hermetically retained by an enclosure or shroud prior to ingress into the mold interior. Pressurization is provided within the mold interior and between the mold sample and the mold wall. To facilitate such pressurization, in an embodiment, an engaging lip of the shroud or passageway seals with the container base, though not necessarily hermetically, in order to retain build up sufficient gas pressure in the mold receptacle to force the mold specimen out of the mold receptacle.

(7) In order to permit the influx of gas, simultaneously with the drilling, the drill is provided with passages such as flutes to enable gas or air to travel around the drill and come from the tip of the drill through the perforation, into the mold receptacle and into contact with the base of the concrete sample once the drill has perforated a wall (usually the base) of the mold. If the mold, with contained sample is inverted, the base wall is on top with mold being held while the sample is pushed out of the bottom opening. Perforation is generally in a wall of the mold receptacle opposite an opening of the receptacle.

(8) Continued pent up continued supply of the gas or air within the mold receptacle builds up pressurization of the gas or air within the mold receptacle against the mold sample. The simultaneous application of drill and gas pressurization within the mold receptacle serves to prevent the drill from over-travel and excessive contact with the mold sample. As the drill extends past the base of the mold, the mold sample is lifted or pushed away from contact with the drill.

(9) As part of the method, if necessary, gas pressure sufficient to lift the specimen out of the mold is determined prior to the drilling. The shroud enclosure is sufficient to resist the gas pressure and to maintain sufficient gas pressure to force the molded sample out of the mold at a rate of about several seconds. Prolonged extraction is not desired in order to facilitate specimen removal for testing particularly if there are numerous samples. Nevertheless a slow rate of removal is encompassed herein. It is, of course, not desirable that the force of the gas pressure be overly excessive whereby the specimens rapidly shoot out of the mold unless checked.

(10) The drill structure may be in an upward orientation with the mold sample in a jig above the drilling structure. Perforation is in an upward direction and the mold sample is lifted from the mold receptacle by the applied air or fluid pressure. Alternatively, the mold is placed with the open end facing down and the mold base facing up. In this orientation the drilling structure is configured similar to a drill press with the air pressure serving to raise the mold receptacle upwardly with removal of the mold receptacle from the sample. In this latter embodiment less pressure is required for the removal based on the relative weights of the concrete sample and plastic receptacle. Greater care is however required to ensure that the downward movement of the drill bit does not overtake the air pressure removal of the mold receptacle with inadvertent damage to the sample by the drill bit.

(11) With respect to the drawings, in FIG. 1, a molded concrete sample 1 is shown, as contained within cylindrical plastic mold container 2 and capped with loosely fitting cap 3. In FIG. 2, the mold 2 with contained concrete sample 1 is snugly seated within a cylindrical tube jig 4 having an internal retaining lip 5. A drill structure 10 is retained slightly below the retaining lip 5 via cross bar 6. As shown in FIG. 3, a drill bit 11 having extending flutes 12 and a flat cutting head 13 is used to perforate the mold receptacle at its base. Cutting head 13 is provided with slight peripheral protrusion 13a which minimizes any damaging extension area while providing a rotatable perforation element. The protrusion is angled so as to cause pressurized air to more easily flow between the mold sample and the adjacent mold receptacle wall in order to facilitate initiating separation of the mold sample from the adjacent receptacle wall.

(12) FIG. 4, shows, in cross section, drill bit 11 contained with shroud 14 and spaced therefrom by an air passage 15. Air inlet 16 feeds into the air passage 15 at 16a whereby pressurized air is able to pass through the air passage around drill bit 11 and the air pressure is also directed through the flutes 12 an out of space 13b at the drill cutting head 13.

(13) FIG. 5 shows the effect of the air pressure exiting at the drill head 13 in impinging on the base 1a of sample 1 after the drill head 13 has cut through the base 2a of mold receptacle 2. The snug fit interface 7 between the mold sample 1, as molded within the receptacle 2, provides sufficient frictional resistance whereby the sample is able to be controllable removed from the mold sample by air pressure alone and without detrimental contact with a drill, nail, awl or any perforating device. The snug fit also serves to minimize air build-up leakage whereby pressurization of the air is facilitated. The shroud or passageway which direct the air to be pressurized within the mold interior is shown in the figures as passages 13b, 14, and 15.

(14) It is understood that the above example and description is only illustrative of the invention and that changes in structure and materials including materials being molded and mold shape are possible without departing from the invention as defined by the following claims.