US3006505A - Apparatus for mixing and dispensing measured quantities of fluid pigments - Google Patents

Description

Oct. 31, 1961 l. LEVIN 3,

APPARATUS FOR MIXING AND DISPENSING MEASURED QUANTITIES OF FLUID PIGMENTS Filed Jan. 30, 1959 2 Sheets-Sheet 1 O O 23 Q 4 /2 1 38 0 0 0 I l I 4 2/ l I 1 Z22 f E i? 1 1 42 :0 0 {ED GD I: I:1 26 I, :I 000 o 1: k :Qzz :0 i 53 I 208008 QED 58 .kb 56 O 1;. :H I v 0 0o 1 32 INVENTOR mg g l 3.9 0 0 0 29 I 27 BY KARL, E Lamas ATTORNEY LEVIN 3,006,505 APPARATUS FOR MIXING AND DISPENSING MEASURED QUANTITIES OF FLUID PIGMENTS Filed Jan. 30, 1959 Oct. 31, 19 61 2 Sheets-Sheet 2 INV EN TOR M W KQRR LU i LOCKS ATTORNEY United States Patent APPARATUS FOR MIXING AND DIPENING MEASURED QUANTETEES OF FLUID PIG- NENTS Isador Levin, Baltimore, Md, assignor to Baltimore Paint and Qhemieal Corporation, Baltimore, Md, a corporation of Maryland Filed Jan. 39, 1959, Ser. No. 79%,631 6 Claims. (Cl. 22226) The present invention relates to dispensers, and more particularly to highly accurate and low cost dispensers for thin or viscous colorant liquids or pastes, such as paint pigment, in which recirculation of the pigment through the parts of the dispenser is provided.

It has been customary in the past for retail outlets to sell paint in relatively small quantities, from a pint up to several gallons. in one common type of merchandising operation, the paint manufacturer selects a limited number of colors to produce, and these are packaged in metal containers and shipped to the retail outlets for resale. The ultimate paint user, therefore, had a limited number of colors from which to choose, and for example had a choice only of a light or dark green, and did not have available for his selection any other of the green colors or shades than the two particular ones. In more recent times, the so-called decorator colors have come into greater prominence and the demand for them has been correspondingly increased.

Decorator colors may be considered to be a greatly expanded range of shades and tints of the various colors. To supply the demand for the great range of colors, various workers in the art have endeavored to provide the paint retailer with some apparatus for mixing the great many colors in the desired range. To this end, these workers have started with the basic concept that a white or colorless paint base should be furnished in the pint, quart and gallon containers to the retailer and that the retailer should have available to him the pigment for giving the desired color to the paint. Thus, a retailer could provide his customer on order with any one of perhaps a thousand shades of paint simply by mixing the paint base and the necessary pigment. The art of mixing varying amounts of one, two'or three pigments with a paint base and in varying pigment amount is known, and it is known that by varying the pigment quantities there will result a wide variety of resulting colors of the paint.

With the above basic concept of paint marketing, there has been provided several machines and systems in accordance therewith. These machines and systems have been subject to one common and major drawback, the complexity and high cost thereof. As an example of apparatus that has been provided previously, there may be mentioned one high cost powered machine having complex automatic valves and controls with attendant electric circuitry, and in another example a number of transfer containers were required thus involving much handling of the apparatus by the person performing the paint mixing.

Other attempted solutions to the problem have resorted to containers with an outlet from the bottom, controlled by a valve. Such apparatus have not been satisfactory as they are prone to seepage, and thus are so untidy that they become unsuitable for use at the retail level.

An ancillary problem generated by the advent of decorator" colors is that the painting contractor is called upon to provide the same numerous shades, tints and hues as the retail outlet. As such contractors transport their equipment and materials in automobiles or panel trucks, they are not able to carry the large machines, above mentioned, with them; equipment provided especially for their use heretofore has been inaccurate and untidy, and has therefore been unsatisfactory.

A further problem in the provision of decorator colors apparatus is that of uniformity of the final product. Otherwise stated, the color of the paint, as formulated with the equipment, must match that shown on the sample. This requirement can be met if highly accurate quantities of well mixed pigments are dispensed from the machine or equipment. To meet these needs, many workers in the art have provided complex and expensive measuring pumps, and some have additionally added a circulatory system between the containers, pumps and dispensers, thus adding even more to the cost of the equipment. Thus, the solutions to the problem of accuracy and uniformity, ofiered by those skilled in the art, have been expensive and bulky.

An object of the present invention is to provide an economic dispenser for thin or viscous colorant liquids or pastes.

Another object of the present invention is the provision of a dispenser for thin or viscous colorant liquids or pastes wherein the liquids or pastes can be readily recirculated.

Yet another object of the present invention is to provide a dispenser wherein a movable spout may be readily placed in recirculating position.

A still further object of the present invention is the provision of a dispenser having an economical indicator to indicate the level of fluid in the dispenser.

Still another object of the present invention is to provide a low cost dispenser from which highly accurate quantities may be readily dispensed.

A further object of the present invention is the provision of a process for coloring paint.

Other objects and the nature and advantages of the instant invention will be apparent from the following description taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective view of a dispenser in accordance with the present invention.

FIG. 2 is a cross-sectional view taken on the line 2-4 of FIG. 1.

FIG. 3 is a plan view, partly in section, of the dispenser shown in FIG. 1. W

FIG. 4 is an elevational View of an agitator comprising a part of the dispenser of FIG. 1. 7

FIG. 5 is a partial cross-sectional view of another form of the dispenser of the invention.

FIG. 6 is a cross-sectional view of still another embodiment of the invention, taken on the lines 6-6 of FIG. I. l

FIG. 7 is a plan view of the dispenser of FIG. 6.

FIG. 8 is a plan view of another embodiment of the invention. 7 I

Referring now to the drawings, wherein like reference numerals are used to designate like or corresponding parts throughout the several views, there is shown in FIG. 1 a/dispenser 10 comprising a container 11 having an open top, a cover 12 for the container 11 and a first pump 13 and second pump 14 mounted in the cover. there may be seen mounted in the cover 12 an agitator 15. Cover 12 further comprises a hole 16.

Referring now to FIG. 2, it may be seen that the container 11 has an annular, peripherally extending and inwardly directed flange 21. The cover 12 is preferably of a transparent material and has a downwardly directed discwlike extension 22 centrally thereof, the extension 22 having a wall 23 that is generally perpendicular to the plane of the cover 12 and is slightly smaller than the opening defined by the flange 21.

The first pump 13 has a relatively high capacity and is mounted in a bore 24 in the cover 12. The pump 13 comprises a pump barrel 26 and an eduction tube 27 connected therewith. The eduction tube 27 has a valve seat 28, and a ball valve 29 is adapted to seat thereon. A retainer bar 31 is placed across the passage within the eduction tube 27 and serves to prevent the ball valve 29 from moving away from the seat 28 to a too great extent.

The pump 13 has a piston 32 in the barrel 26, and this piston 32 has a hollow plunger 33 attached thereto and extending upwardly out of the barrel 26. A second valve seat 34 is provided at the upper end of the plunger 33, and a ball valve 36 cooperates therewith.

A laterally extending spout 37 having a downwardly directed discharge end 38 is secured in fluid communicating relationship with the plunger 33 adjacent the top thereof.

At the lower end of the barrel 26 of pump 13 the pump is joined to a conical portion 39 and it is to this portion 39 that the eduction tube 27 is connected. The juncture of conical portion 39 with barrel 26 forms a limiting stop that serves to arrest the downward movement of the piston 32. The upward movement of piston 32 is arrested by a stop 41 that extends into the barrel 26. These stops thus serve to aflord a definite and predetermined capacity to the pump 13, and as will be readily understood by moving the pump plunger 33 and piston 32 a given fraction of the full amount of the travel thereof, the amount of material dispensed will be proportional to that fraction of the total travel that the piston and plunger have moved. To provide for ready measurement of the amount of pigment dispensed, the plunger 33 is provided withgraduations 42 on the exterior surface thereof, and it will be understood that the graduations 42 are proportional to the capacity of the pump 13 at various positions of the plunger 33. An index for the graduations 42 is provided by the top edge of an end closure 43. The closure 43 has a downwardly extending part 44 and an outwardly extending flange 46. The pump barrel 26 has an outwardly extending flange 47 and an upward extension 48. The part 44 extends within the extension 48, and the flanges 46 and 47 thus clamp the cover 12 between them. Since the extension 48 and part 44 are secured together, this construction serves to attach the pump 13 to the cover 12.

As will be readily understood, when the plunger 3-3 and piston 32 are raised, ball valve 36 will seat on the seat 34 and ball valve 29 will be raised from the seat 28, and thus pigment will flow into the pump barrel through the eduction tube 27. Using the graduations 42, one may move the plunger 33 upwardly a predetermined amount, and then when the plunger 33 is pushed downwardly the ball valve 29 will seat and the ball valve 36 will unseat to cause dispensing of the pigment through the spout 37 and the discharge end 38. Because the pistons 32 and plunger 33 are rotatable within the barrel 26, the discharge end 38 of the spout 37 may be moved to various selected places.

The second pump 14 is substantially identical in construction with the pump 13, the pump 14 differing from the pump 13 in that it has a substantially smaller barrel than the pump 13 with smaller graduations, and it will be readily understood therefrom that the capacity of the pump 14 is markedly lower than the capacity of the pump 13.

Two pumps have been used on the dispenser of the present invention in order to provide a dispenser that can dispense pigment in relatively accurate quantities with extremely low cost equipment. These pumps 13 and 14 are made of a readily available plastic material, and can be produced in quantity at a very low cost. This is so because no expensive machining is required as is the case with the use of machined-part pumps. Pumps thus made are accurate to a relatively high degree, and by the use of two pumps of different capacities there is provided a dispensing system that is both economical and highly accurate.

Referring again to FIG. 1, there may be seen therein an opening 16, and this opening 16 in the cover 12 is positioned in a particular place in relation to the pumps 13 and 14 and the agitator shaft 55. In FIG. 3 it may be seen that the pumps 13 and 14 are relatively close together near one edge of the cover 12. The opening 16 is at an almost diametrically opposite point in the cover 12. As may be seen, the opening 16 is spaced from the barrel of the pump 13 the same distance as the discharge end 38 of the spout 37. Similarly, the spout 37 of the pump 14 is of such length that the discharge end 38' thereof is also above the opening 16. The shaft 55 serves as a placing abutment for both the spout 37 of pump 13 and the spout 37' of pump 14, and as may be seen from FIG. 3 the sides of the spout 37 and 37' abut against said shaft to thus position the discharge end 38 and 38 of the spouts 37 and 37 over the opening 16.

The agitator 15 may be seen in FIG. 4 to comprise a shaft 55 having a crank 56 at the upper end thereof, and a paddle 57 fixed on the lower end thereof. The paddle 57 is preferably made of metal, and has a horizontally extending indicating slit 58 therein, and immediately below the slit 58 appears the word LO, this serving as an indicia and being formed of holes punched in the metal of the paddle 57. As will be understood, the slit 58 and the Word LO may be readily seen through the transparent cover 12.

In use, the retail outlet will be provided with a number of containers 11 having thin or viscous colorant liquids or pastes of different colors therein. For example, the retail outlet may be provided with ten or twelve different pigment containers. The dispensers 10 are placed at a convenient location, and are withdrawn from that location as needed. Alternatively, the various dispensers 10 may be mounted upon a rotatable support, so that they may be each in turn brought above a shelf on which the base paint container is placed, with the lid thereof removed. The user then mixes the pigment within the container 11 by use of the agitator 15. Both of the spouts 37 and 37 are moved over the opening 16, with the sides of the spouts abutting against the shaft 55 and the pumps 13 and 14 operated. This serves to prime the pumps 13 and 14 and the spouts 37 and 37 and ensures the dispensing of an accurate quantity of the pigment. After the operator is satisfied that the pumps 13 and 14 are fully primed and are in operating condition, by observing the streams of pigment from the discharge ends 38 and 38', he simply revolves the spout 37 so that the discharge end 38 thereof is over the container of base paint. The plunger 33 is then raised the desired amount as determined by the graduations 42, and then the plunger is lowered to cause the dispensing of the desired quantity into the base paint containers. The procedure is repeated with respect to pump 14, and there is thereby assured the dispensing of an amount of pigment that is sufiiciently accurate for painting purposes.

In FIG. 5, there is shown a dispenser for paint pigment that is particularly adapted for use by painters. Painters are often called upon to provide many shades and tints of colors, and it is desirable that they be able to provide their customers with the desired color range. Also, the painter is not able to have bulky equipment at his disposal, such as known paint coloring and mixing apparatus, and there has been provided for the painters use only cumbersome and relatively unmanageable apparatus. The dispenser of FIG. 5 comprises a container 61 that is small and readily handled. Preferably, dispenser 61 will hold about one quart of pigment. Container 61 is provided with a top 62 having openings 63 and 64 therein, spaced as shown. Each of the openings 63 and 64 has an upstanding screw threaded neck, 65 and 66, respectively therearound. On the neck 65 is a cap 65' that has mating screw threads, and a hole 67 therein. A pump 68 is secured to the cap 65' and extends through the hole 67. Pump 68 is substantially identical to the pumps 13 and 14, and will therefore not be described in detail. Pump 68 has a laterally extending spout 69 with a discharge end 70 that is downwardly directed, and is of such a length as to be above the hole 64. A screw threaded cap 71 is provided for the neck 66.

In order to agitate the pigment in the container 61, the cap 71 is placed upon the screw threaded neck 66 and the container 61 agitated by a manual shaking. The cap 71 may then be removed and the discharge end 70 placed above the opening 64. Thereafter, the plunger of pump 68 is reciprocated several times to ensure proper priming and flowage of the pigment. As will be apparent, this serves to recirculate the pigment back into the container 61 without waste or mess. When it is desired to dispense a measured quantity of pigment into a container of base paint, it is only necessary to withdraw the plunger of the pump 68 a particular amount as determined by the graduations on the plunger of the pump 68, and then to push down on the plunger to cause a dispensing of a measured quantity of pigment. I

In FIGS. 6 and 7 there is shown another embodiment of the invention, wherein an open topped container 11 is provided with a transparent cover 12 having a pump 13 mounted in a hole therein with the pump barrel extending downwardly into the container, as shown. The plunger 33 of the pump 13 has an outwardly and downwardly extending spout 37 in fluid communication therewith, with the end of the spout 37 of a length to be placed above the hole 16 in cover 12. A hole 76 is provided centrally of the cover 12', which hole communicates with a hole in bearing block 74 that is secured, as by cementing, to the cover 12. An agitator shaft 75 extends through the hole 76 and the hole in the bearing block 74 and has a blade 77 secured to the lower end thereof. A suitable knob 78 is provided at the upper end of shaft 75 to aid in the manipulation thereof.

A bracket 80, of generally L-shape has a leg thereof secured to the container 11 adjacent its top edge. Bracket 80 has an inwardly extending lip 81 with a hole therethrough. A hole 82 in the cover 12 is in registry with the hole in the lip 81 of bracket 8!), and a headed fastener 83 having depending, outwardly bowed spring legs passes through the hole 82 and the hole in the lip 81. Thus, the cover 12 is removably secured to the container 11.

The embodiment of the invention shown in FIG. 8 is generally similar to that shown in FIGS. 6 and 7. However, the cover 12 is secured to the container 11 by screws 84 extending through appropriate holes 82 in the cover 12, the screws 84 having a threaded connection with the inwardly extending lip 81. There are two brackets 80 provided in the FIG. 8 embodiment.

When it is desired to use the embodiments of FIGS. 6 and 8, it is only necessary to remove the cover 12, by removing the fastening means 83 or 84, and then filling the container 11 with the necessary viscous pigment. It will be understood, of course, that similar containers 11 are filled with other pigments of difierent colors. Thereafter, the cover 12 is replaced, and secured to the container 11. When it is desired to dispense the pigment for the purpose of preparing a particular color of paint, it is only necessary to position the spout 37 above the hole 16 and to reciprocate the plunger 33 in order to charge the pump 13, and to recirculate the pigment. Periodically, the agitator knob 78 will be manipulated in order to provide for thorough agitation of the pigment. Dispensing into a container is accomplished as heretofore indicated, i.e., by pulling the plunger 33 upwardly a desired amount, as indicated by markings thereon, and then rotating the spout 37 over the can of base paint. Then the plunger 33 is lowered to dispense a measured amount of pigment into the can of base paint through the spout 37.

There has been provided dispensers that are extremely economical to produce and which are capable of dispensing thin or viscous colorant liquids or pastes in accurate quantities. These dispensers provide for ready, fully effective agitation of the pigment and for visible, manual recirculation of the pigment so as to prime the pump and ensure proper functioning thereof, the recirculation being under fool-proof control. Uniquely the pumps are top mounted to the container. There has also been provided means for readily and accurately positioning the fully visible discharge spout of the dispensing pump to the dispensing or recirculating position, as well as an economical system for ensuring a relatively high accuracy of dispensed material. The embodiment of FIG. 2 provides a portable unit for painters use having a quantitative dispenser.

It will be obvious to those skilled in the art that various changes may be made without departing from the spirit of the invention and therefore the invention is not limited to what is shown in the drawings and described in the specification but only as indicated in the appended claims.

What is claimed is:

1. A dispenser for thin or viscous colorant liquids or pastes, such as paint pigment, comprising a container having an open top and an annular peripherally extending inwardly directed flange, a cover of transparent material having a downwardly directed disc-like extension centrally thereof, said extension having wall means generally perpendicular to the plane of said cover and being slightly smaller than the opening defined by said flange, a first pump mounted in a bore in said cover and having a pump barrel and eduction tube extending into said container, a valve seat in said eduction tube and a ball valve adapted to seat on said valve seat, a piston in said barrel having a hollow plunger attached thereto and extending upwardly out of said barrel, said piston and plunger being rotatable in said pump barrel, a second valve seat in said plunger, a second ball valve adapted to seat on said second valve seat, a laterally extending spout having a downwardly directed discharge end se cured in fluid communicating relationship with said plunger adjacent the top thereof, said plunger having graduations on the exterior surface thereof proportional to the capacity of said pump at various positions of saidplunger, an opening extending downwardly through said cover and spaced from said barrel the same distance as the discharge end of said spout, an agitator having a shaft extending through a second bore in said cover and having the lower end thereof in said container, a paddle on said shaft having a refill-indicating indicia thereon, the side of said spout abutting said shaft when the discharge end of said spout is over said opening, and a second pump and spout mounted in a third bore in said cover, said second pump having a substantially smaller barrel than said first pump, the discharge end of the spout of said second pump being above said opening and the side of the spout of the second pump abutting said shaft in one position thereof, whereby both said pumps may be brought into positions abutting said shaft to thereby locate the discharge ends of the spouts thereof over said opening, and whereby said pumps may be caused 7 to rapidly dispense a measured quantity of pigment from said container.

2. A dispenser for thin or viscous colorant liquids or pastes, such as paint pigment, comprising a container having an open top and an annular peripherally extending inwardly directed flange, a cover having a downwardly directed disc-like extension centrally thereof, said extension having wall means generally perpendicular to the plane of said cover and being slightly smaller than the opening defined by said flange, a first pump mounted in a bore in said cover and having a pump barrel extending into said container, a piston in said barrel having a hollow plunger attached thereto and extending upwardly out of said barrel, said piston and plunger being rotatable in said pump barrel, a laterally extending spout having a downwardly directed discharge end secured in fluid communicating relationship with said plunger adjacent the top thereof, said plunger having graduations on the exterior surface thereof proportional to the capacity of said pump at various positions of said plunger, an opening extending downwardly through said cover and spaced from said barrel the same distance as the discharge end of said spout, an agitator having a shaft extending through a second bore in said cover and having the lower end thereof in said container, a paddle on said shaft, the side of said spout abutting said shaft when the discharge end of said spout is over said opening, and a second pump and spout substantially identical to said first pump and spout mounted in a third bore in said cover, said second pump having a substantially smaller barrel than said first pump, the discharge end of the spout of said second pump being above said opening and the side of the spout of the second pump abutting said shaft in one position thereof, whereby both said pumps may be brought into positions abutting said shaft to thereby locate the discharge ends of the spouts thereof over said opening, and whereby said pumps may be caused to rapidly dispense a measured quantity of pigment from said container.

3. A dispenser for thin or viscous colorant liquids or pastes, such as paint pigment, comprising a container having an open top, a cover, a first pump mounted in a bore in said cover and having a pump barrel extending into said container, a piston in said barrel having a hollow plunger attached thereto and extending upwardly out of said barrel, said piston and plunger being rotatable in said pump barrel, a laterally extending spout having a downwardly directed discharge end secured in fluid communicating relationship with said plunger adjacent the top thereof, an opening extending downwardly through said cover and spaced from said barrel the same distance as the discharge end of said spout, an agitator having a shaft extending through a second bore in said cover and having the lower end thereof in said container, the side of said spout abutting said shaft when the discharge end of said spout is over said opening, and a second pump and spout substantially identical to said first pump and spout mounted in a third bore in said cover, said second pump having a substantially smaller barrel than said first pump, the discharge end of the spout of said second pump being above said opening and the side of the spout of the second pump abutting said shaft in one position thereof, whereby both said pumps may be brought into positions abutting said shaft to thereby locate the discharge ends of the spouts thereof over said opening, and whereby said pumps may be caused to rapidly dispense a measured quantity of pigment from said container.

4. A dispenser for thin or viscous colorant liquids or pastes, such as paint pigment, comprising a container having an open top and an annular peripherally extending inwardly directed flange, a cover of transparent material having a downwardly directed disc-like extension centrally thereof, said extension having wall means generally perpendicular to the plane of said cover and being slightly smaller than the opening defined by said flange, a pump mounted in a bore in said cover and having a pump barrel and eduction tube extending into said container, a valve seat in said eduction tube and a ball valve adapted to seat on said valve seat, a piston in said barrel having a hollow plunger attached thereto and extending upwardly out of said barrel, said piston and plunger being rotatable in said pump barrel, a second valve seat in said plunger, a second ball valve adapted to seat on said second valve seat, a laterally extending spout having a downwardly directed discharge end secured in fluid communicating relationship with said plunger adjacent the top thereof, said plunger having graduations on the exterior surface thereof proportional to the capacity of said pump at various positions of said plunger, an opening extending downwardly through said cover and spaced from said barrel the same distance as the discharge end of said spout, an agitator having a shaft extending through a second bore in said cover and having the lower end thereof in said container, a paddle on said shaft having a refill-indicating indicia thereon, the side of said spout abutting said shaft when the discharge end of said spout is over said opening, whereby said pump may be brought into positions abutting said shaft to thereby locate the discharge end of the spout thereof over said opening, and whereby said pump may be caused to rapidly dispense a measured quantity of pigment from said container.

5. A dispenser for thin or viscous colorant liquids or pastes, such as paint pigment, comprising a container having an open top and an annular peripherally extending inwardly directed flange, a cover having a downwardly directed disc-like extension centrally thereof, said extension having wall means generally perpendicular to the plane of said cover and being slightly smaller than the opening defined by said flange, a pump mounted in a bore in said cover and having a pump barrel extending into said container, a piston in said barrel having a plunger attached thereto and extending upwardly out of said barrel, said piston and plunger being rotatable in said pump barrel, a laterally extending spout having a downwardly directed discharge end secured in fluid communicating relationship with said pump adjacent the top thereof, said plunger having graduations on the exterior surface thereof proportional to the capacity of said pump at various positions of said plunger, an opening extending downwardly through said cover and spaced from said barrel the same distance as the discharge end of said spout, an agitator having a shaft extending through a second bore in said cover and having the lower end thereof in said container, a paddle on said shaft, the side of said spout abutting said shaft when the discharge end of said spout is over said opening, whereby said pump may be brought into positions abutting said shaft to thereby locate the discharge end of the spout thereof over said opening, and whereby said pump may be caused to rapidly dispense a measured quantity of pigment from said container.

6. A dispenser for thin or viscous colorant liquids or pastes, such as paint pigment, comprising a container having an open top, a cover, a pump mounted in a bore in said :cover and having a pump barrel extending into said container, a piston in said barrel having a plunger attached thereto and extending upwardly out of said barrel, said piston and plunger being rotatable in said pump barrel, a laterally extending spout having a downwardly directed discharge end secured in fluid communicating relationship with said pump adjacent the top thereof, an opening extending downwardly through said cover and spaced from said barrel the same distance as the discharge end of said spout, an agitator having a shaft extending through a second bore in said cover and having the lower end thereof in said container, a paddle on said shaft, the side of said spout abutting said shaft when the discharge end of said spout is over said 9 opening, whereby said pump may be brought into position abutting said shaft to thereby locate the discharge end of the spout thereof over said opening, and whereby said pump may be caused to rapidly dispense a measured quantity of pigment from said container.

References Cited in the file of this patent UNITED STATES PATENTS 10 Wertz Dec. 14, 1926 Peterson et a1. Jan. 11, 1927 White June 21, 1927 Boe Aug. 2, 1927 Featherstone Mar. 22, 1932 Banowitz Feb. 28, 1956 Gray Aug. 5, 1958 FOREIGN PATENTS Italy Dec. 24, 1934 Germany Apr. 26, 1956

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