BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the invention is described in detail below, with reference to the accompanying drawings, wherein:
FIG. 1 is a right front perspective, explosion view of a mantle block base holder with four, interchangeable reaction block wedges according to a preferred embodiment of my invention, in an intended use upon a laboratory magnetic stirrer hot plate, that is shown in dotted line;
FIG. 2 is a top plan view of the base holder of FIG. 1;
FIG. 3 is a bottom plan view of the base holder of FIG. 1;
FIG. 4 is a left side elevation view of the base holder of FIG. 1, the right side being a mirror image thereof;
FIG. 5 is a vertical cross-section view of the base holder of FIG. 1, taken along a front to back diameter; with a superposed reaction block wedge holding a vial, and shown in an intended use upon a top surface of a laboratory magnetic stirrer and hotplate, that is shown in dotted line.
FIG. 6 is a top plan view of a first reaction block wedge with bores able to accommodate 4 ml vials.
FIG. 7 is a top plan view of a second reaction block wedge with bores able to accommodate either 20 ml, 30 ml or 40 ml vials.
FIG. 8 is a vertical cross-section detail view of a portion of a reaction block wedge able to accommodate a 20 ml vial.
FIG. 9 is a vertical cross-section detail view of a portion of a reaction block wedge able to accommodate a 30 ml vial.
FIG. 10 is a vertical cross-section detail view of a portion of a reaction block wedge able to accommodate a 40 ml vial.
FIG. 11 is a top plan view of a third reaction block wedge with bores able to accommodate 16 ml vials.
FIG. 12 is a top plan view of a fourth reaction block wedge with bores able to accommodate 8 ml vials.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment illustrated in FIG. 1 comprises a mantle block base holder of machined aluminum that is configured with an upper circular surface 2 and a circumferential upper lip or wall 14 to engage and align up to four reaction block wedges 4, 6, 8, and 10 and a lower surface and circumferential lower lip or wall 16 adapted to engage upon and around the circumference of a supporting hot plate 22 of a hotplate/magnetic stirrer 12, shown in dotted line. The upper surface 2 includes a drain bore 20 to allow liquids to drain down and away from the hot plate surface 22.
Each reaction block wedge is a quarter circle in plan view, has a plurality of spaced vertical bores for a particular vial size and a thickness that permits about one half of the height of the particular vial size to fit snugly within the bore. The radius of each wedge is about 3.125 inches. The diameter of the upper surface 2 inside the upper lip 14 is about 6.28 inches. The diameter of the lower surface 18 inside the lower lip 16 is about 5.35 inches. A bore 129 inches by 0.75 inches deep provided as the thermowell 24, 26, 28, 30 is located somewhat centrally in the top surface of the respective wedges 4, 6, 8, and 10.
The centerline of each bore is on a circle with a diameter that is less than the diameter of the hotplate 22. It has been found that the magnetic stirrers in a vial do not rotate smoothly when a vial centerline is positioned at or outside the outer diameter of the hot plate. The locus of centerlines for the outer set of bores in a wedge range from a radius of 2.75 inches for the 4 ml wedge 8 to a radius of about 2.5 inches for the 40 ml wedge 4. The diameter of the hotplate to be used is less than 5.35 inches.
A representative 30 ml vial of height T(30) is illustrated above a bore in wedge 4 that has a vertical thickness H(30). A representative 4 ml vial of height T(4) is illustrated above a bore in wedge 8 that has a vertical thickness H(4). The ratio of T/H is greater than about 2. These relationships create a safe and effective heat transfer for the typical half-full liquid samples within each vial. A direct contact of the wedge bore with the vial wall portion that is typically above the liquid level is to be avoided. Boil over of a sample out of the vial is minimized by not contact heating the glass portion that is not conducting heat into an adjacent liquid. The base holder and wedge are of aluminum and do not to interfere with the magnetic field, being generated from below the hot plate surface.
FIGS. 2 and 3 show top and bottom plan views of the base holder. The upper surface 2 includes a drain bore 20 in an annular space near the upper lip 14, and outside the outer surface of the lower lip 16 in order to allow any accumulated liquids to drain through to the bottom surface 18 and down to a location away from the hot plate 22. The upper lip 14 is sized to be about 0.75 inches high and 6.28 inches in diameter at its inner surface. The lower lip 16 is sized to be about 0.5 inches high and 5.350 inches in diameter at its inner surface, or slightly greater in diameter than the 5.2 inch hotplate diameter of a preferred device, the Opti CHEM Model CG-1993-01 hot plate stirrer from Chemglass of Vineland N.J. The thin wall thicknesses of the horizontal surface 2, the upper lip 14 and the lower lip 16 quickly conducts heat radially inward and upward towards the mass of the wedge elements 4, 6, 8, 10. The base holder and the individual reaction blocks overall are configured to have a minimized amount of mass and thermal capacity, in order to quickly respond to changes in temperature being required by the controller (not illustrated) which dictates the temperature at the hot plate surface 22.
FIG. 5 further illustrates an intended use of the assembled reaction block upon a top surface of a conventional laboratory magnetic stirrer and hotplate, 12FIG. 5 is a vertical cross-section view of the base holder of FIG. 1, taken along a front to back diameter. The superposed reaction block wedge 4 is shown holding a 30 ml capacity vial of a height T (30) that is about 2.5 inches, while the wedge has a height H (30) of about 1.25 inches. FIG. 5 shows an intended use, with the lower surface 18 resting upon a top surface 22 of a laboratory magnetic stirrer and hot plate, that is shown in dotted line. The flat lower surface 18 and lower lip 16 are of a thin wall thickness. The inside of lip 16 is 5.35 inches in diameter to engage over and around the flat area but also slightly outside the edge of hot plate upper surface 22. In this manner, the base holder and superposed reaction blocks will remain fixed and located well within the magnetic field of the laboratory stirrer, and the hot surface 22 will be shielded from an inadvertent contact with the hands of a lab technician.
Preferred same-shaped reaction blocks in a four piece wedge configuration are shown in FIGS. 1, 6, 7, 11 and 12. All of the wedges have the same dimensions in a plan view, and any four can fit together to make a circular combination with a diameter of slightly less than 6.28 inches and each wedge is interchangeable at any of four locations inside of the lip 14 of the base holder.
FIG. 6 is a top plan view of a first reaction block wedge 8 of anodized, 6061 aluminum with 8 bores able to accommodate 4 ml vials. The bore size DS is about 0.597 inches in diameter and drilled 0.75 inches deep into a wedge with a height of 0.813 inches. Each bore has a central drain bore of about 0.125 inches. A thermowell about 0.129 inches in diameter is drilled 0.75 inches deep.
FIG. 7 is a top plan view of a second reaction block wedge 4 of anodized, 6061 aluminum with 4 bores able to accommodate either 20 ml, 30 ml, or 40 ml vials. The bore size DXL is about 1.1 inches in diameter for all three versions. Each thermowell 24 is about 0.129 inches in diameter. In this manner the same plan view dimensions and bore array can be used to make interchangeable reaction block wedges for at least three different vial sizes, simply by changing the vertical height of each wedge.
As shown in the detail partial section view of FIG. 8, for a 20 ml version of wedge 4 the bore and thermowell 24 are drilled to a depth B(20) that is 0.938 inches deep into a wedge of black anodized aluminum with a height H(30) of 1.0 inches. As shown in the detail partial section view of FIG. 9, for a 30 ml version the bore and thermowell 24 are drilled to a depth B(30) that is 1.18 inches deep into a wedge of green anodized aluminum with a height H(30) of 1.25 inches. As shown in the detail partial section view of FIG. 10, for a 40 ml version the bore and thermowell 24 are drilled to a depth B(40) that is 1.68 inches deep into a wedge of orange anodized aluminum with a height H (40) of 1.75 inches. Each bore has a central drain bore 34 of about 0.125 inches.
FIG. 11 is a top plan view of a third reaction block wedge 6 of red anodized, 6061 aluminum with 4 bores able to accommodate 16 ml vials. The bore size DL is about 0.85 inches in diameter and drilled 1.25 inches deep into a wedge with a height of 1.313 inches. Each bore has a central drain bore of about 0.125 inches. A thermowell 26 about 0.129 inches in diameter is drilled 1.25 inches deep.
FIG. 12 is a top plan view of a fourth reaction block wedge 10 of blue anodized, 6061 aluminum with 8 bores able to accommodate 8 ml vials. The bore size DM is about 0.70 inches in diameter and drilled 1.00 inches deep into a wedge with a height of 1.063 inches. Each bore has a central drain bore of about 0.125 inches. A thermowell 30 about 0.129 inches in diameter is drilled 1.00 inches deep.
While preferred embodiments have been shown and described in order to satisfy the requirements of 35 USC ยง 112, the invention is to be defined solely by the scope of the appended claims
Patent Application
20080056957
