US2045950A - Battery box and process of making the same - Google Patents

Description

June 30, 1936. H TTEL 2,045,950

BATTERY BOX AND PROCESS OF MAKING THE SAME Original Filed July 26, 1932 Lauis VV. Jio ijl'el Patented June 30, 1936 v 2,045,950 v BATTERY Box AND PROCESS OF MAKING THE SAME,

Louis Hottel, Los Angeles, Calif., assignor to Q The Richardson Company, Lockiand, Cincinnati, Ohio, a corporation of Ohio Application July 26, 1932, Serial No. 624,785

Renewed October 12, 1935 9 Claims. (Cl. 136-166) The invention concerns a battery box formed by pressure as distinguished from a box formed by vulcanization, and in which a so-called cold press composition is used such as will set to final form by allowing it to cool in the press in which the molding operation is performed under heat. Invention also resides in the process involved in making the box.

The box is formed by molding the box body and uniting therewith a pre-formed partition, or partitions', which is blended or welded integrally with the material ofthe 'box body during the molding of the latter, the union being due to the pressure exerted during this molding operation in the presence of heat and the subsequent cooling of the molded-together material while still .in the press. A

The invention is illustrated in the accompanying drawing showing in perspective a battery box.

In this drawing, I indicates a pre-formed partition, 2 the box body molded into integral con- I nection with the partition or partitions, the arrows A indicate the general direction in which the grain of the partition runs, and the arrows B indicate the general direction in which the grain of the box body runs.-

In carrying out the process, the partitions are formed first, i. e., independently of the molding operation which produces the body ofthe box.

The material or composition of whichthe par,

titions are formed may be entirely different from the composition or material of which the body portion of the box is composed. This material from which the partitions are made is first sheeted out or calendered to the proper thickness and then the sheets are cut to provide the partitions of the desired sizes These partitions are placed on a warming plate and subjected to a temperaturewhich will aid in conditioning the material of the partitions properly for their union with the body portion of the box, whenthe latter. is

molded with the partitions setin the molding apparatus in proper relation to assumethe prescribedrelation to the walls of the box when molded.

composition used for the body of the box. As one instance of a suitable temperature, 270 F. may be mentioned. The slabs forming the partitions are inserted in recesses or openings in the mandrel ,or core of the molding apparatus and these {5 recesses or openingsmay be those which, in moldation takes place.

ing operations as heretofore practiced, receive the material from the biscuit or mass of moldable material during the molding operation which in said known practice forms the box-and the partitions from the same operation and from the 5 same batch of materials.

Having placed the substantially pre-formed and pr'e-heated partitions in the recesses between the sections of the mandrel or core, and having placed the biscuit or mass of moldable material 10 intended to form the box body on top of the mandrel or core, the press is closed so that the' core or mandrel carrying the substantially preformed partitions and the biscuit of body material enters the mold body and the molding oper- 15 In performing the molding operation, apparatus may be used such as is disclosed in application for Letters Patent of the United States, filed February 9, 1932, Serial No. 591,900, though the invention is not limited in'its 20 manufacture or performance to any particular apparatus. In this molding operation, pressure is immediately exertedupon the body material which therefore fills the recesses within the mold intended to shape and dimension the body of the 25 box. This pressure is also transmitted to and throughout the material comprising the partitions which, being in comparatively soft conditionfwill be compacted or compressed so that it V will conform to the shape of the recess in which 30 said preformed partition was positioned prior to thebe'ginning of the molding operation.

In other words, the pressure due to the molding operation is transmitted through the body material to the edge portion of the substantially 35 pre-shaped, soft material of the slab and throughoutthe depth of the slab. This pressure, toether withthe soft condition of the substan-v tially pre-shaped slab for forming the partition,

causes the material of the slab to flow sufiiciently 40 to acquire its final shape and to effect a firm union with the material which is in theact of being molded into the form of the complete box.

The slab in the molding operation is preferably somewhat more rigid than the material of the 45 body of the box. -In performing the molding operation in connection with an apparatus such, for instance, as that disclosed in my application above referred to, the core carrying the substantially .preformed partition slab and-the heated mass of body forming material on its top is moved up into the mold and heat is delivered to the sections of the mandrel or core. The degree of heat will be, say, about 130 F. This temperature will temperatureand have such a rate of flow as to heat the core to a temperature of about 115 to 212 F. (varying with the character of the compound) within one minute. The proper molding temperature is maintained for approximately seconds after the press is completely closed until displacement. of the hot water takes place, at

which time the cooling system begins the reduction in temperature of the core or mandrel.

The material from which the body of the box is molded may be of a temperature of from 250 F. to 300 F. when it is placed on top of the core or mandrel.

After the press has been closed for about 15 seconds, a reduction of the temperature on,the core starts and continues for from 2 to 5 minutes at which time the molding cycle is completed. The core with the completely molded article is now lowered from the die box and the molded box with the partitions united homogeneously therewith is removed. When the core is about midway of its downward'stroke the cold water is turned 0115 and the hot water is turned on to heat the core. The die box may be heated by circulating hot water so as to maintain it at a temperature of about 110 to 130. F. 4

The partitions of that type of battery box which is made in one piece by well known processes involving a molding operation are the weakest parts of the box. molding the partitions at the same time that the body portion of the box is molded the grain of the partition runsin the direction of the line of pressure, and hence perpendicularlyto the plane of the bottom of the box so that when lateral pressure of a certain degree is brought to bear on the partition it will crack along a line coinciding with the grain.

In my method, however, in which the material of the partition is first sheeted by calendering,

' and then the sheeted material is cut to the proper size and shape for forming the partition, the completed slab is so positioned that it will have its grain running substantially parallel with the plane of the bottom of the box or, in other words, the grain of the partition will run in a direction at right angles to the grain of the box body or from side to side of the box instead of from top to bottom of the box. Lateral strains imposed on such a partition will be at right angles to or across the lengthwise direction of the grain, and hence the partition will flex laterally without breaking, and thus a stronger and more durable partition will be produced than by the usual method of molding the partition simultaneously with the body of the box.

Furthermore, such a pre-formed molded-union partition will be free from flow, lines. A flow line may be described as the line where the material flowing from opposite directions meet during the molding operation. Such flow lines are lines of weakness in the partition where breakages occur under stresses imposed laterally of the partitions. In a partition which is pre-formed by first sheeting or calendering the material, such flow lines do not exist. It may be pointed out further that with a pre-formed, ,set-in partition, into connection with which the body portion is united This is due to the fact that in duringthe inoldingof the latter, the pressure applied during the molding operation will be transmitted to the soft material of the set-in partition and in a direction transverse to the direction of its grain, but in the plane of the sheet or slab so that a compacting effect upon the grain will be exerted rather than a disrupting effect, it being borne in mind, as above mentioned, that the partition is set in the recesses of the mandrel or core with the grain thereof running from side to side of the mandrel substantially parallel with its top face instead of perpendicular thereto. By my invention a strong, laterally flexible partition is provided, and one free from both flow lines and pores, the latter being eliminated by reason of the compactinginfluence of the pressure transmitted during the molding operation to the soft material of the slab or sheet which finally forms the partition, said pressure being exerted in the direction of the plane of said slab. 1 1

The partition forming material may vary in constituents. I give the following as one example: Gilsonite 30%; asphalt 6%; cotton 16.5%; rubber 13.5%; sulphur 2.42%; talc 31.58%. To .a batch of 300 lbs. of this composition is added 1% lbs. of stearic acid. The material according to the above formula will have the quality of flowing under pressure, and will be sheeted as above described by passing it through calender rolls.

The box body material may be composed of bitumen, fibrous binder, and an acid resistant flller, this composition being well known. As the partition is formed separately from the box body the material thereof maybe any desired composition which will give the characteristics of acid resistance, strength, flexibility, and capacity to unite with the box body material during the molding of the latter by a homogeneous flux or blending action.

The following advantages may be enumerated 'as flowing from my invention:

The material of the partition may be of different character from that of the box body, that is to say, either a. composition of a different character from that of the box body may be used, or a material entirely foreign to a composition may be used. a

A rubber composition may be used for the partition having a sufllcient percentage of bitumen to unite with the so-called asphalt or bitumen composition of which the box body may be formed.

The partition may be set with its grain running parallel to the bottom of the box as shown at A in the figure, thus increasing its strength to resist tendency to snap apart either during the molding operation or in use. B in the figure represents the general direction of grain of the box body.

Flow. lines are eliminated due to the pre-forming of the partitions by sheeting or calendering, said flow lines being due to the meeting of the materials flowing from different directions during ordinary molding operation.

Porous spots throughout the partitions are eliminated and particularly at the top edge of the partition. These porous spots are due in the ordinary molding operationto the comparative slow rate of flow of the stoclginto the recesses of the core or mandrel which causes that portion of the stock tochill and become stiff resulting in the formation of voids in the material.

My invention also permits the use of higher temperatures onthe-core without detrimentally afiecting the molding of the partitions, the result being a highly finished inner side of the box having the capacity to increase the acid resistance of the material.

A comparatively cheap grade of material for the box body may be used with a higher grade of material for the partition, this last mentioned part of the box being that where most of the trouble occurs.

The material of the partition may have a higher acid resistance than the material of the body of the box.

I claim:

1. The hereindescribed method of making battery boxes comprising bringing together a heated mass of body forming material and a heated, preformed slab of material to serve as a partition and with said slab in such relation to the mass as will determine the position of the partition in the completed box, and subjecting the materials to molding pressure while under heat to thereby weld or blend the box body material with the slab during the molding of said box body, and allowing the Welded materials to cool, substantially as described.

2. The method comprising making battery box partitions, inserting said partitions between the core sections of a mandrel, applying the battery box material on top of the mandrel and inserting the mandrel with the said box forming material and partitions into the mold, and integrally uniting the body material and the partition under heat, pressure, and subsequent cooling.

3. A process according to claim l in which the partition is placed initially in relation to the mass with its grain running in a direction at right angles to the line of pressure to which the materials are subjected during the molding action.

4. A method of making battery boxes, comprising supporting preformed bitumen-containing material to serve as partition means, and molding under pressure unmolded bituminous plastic material into adhering contact with the said partition means, thereby forming the box body from the said unmolded material and integrally unitfibers in the partition.

ing the box body material with the said partition means during the molding of the box body.

5. A method of making battery boxes, comprising supporting preformed bitumen-containing material to serve as partition means, and molding under pressure unmolded bituminous plastic material into adhering contact with the said partition means while the temperature of the said unmolded material is raised, thereby forming the box body from the said unmolded material and integrally uniting the box body material with the partition means during the molding of the box body.

6. An unvulcanized battery box comprising a preformed partition, and a box body molded, from unformed material, into connection with the said preformed partition, the said box body and preformed partition being made of material containing asphaltic matter.

' 7. A battery box comprising an unvulcanized box body and preformed partition means integral with the said box body, the said partition means having a grain running in a direction substantially parallel with the bottom of the box, and having a diiferent composition from the composition of the box body, and said partition being free from meeting or flow lines and of higher acid resistance than the box body.

8. An. unvulcanized battery box comprising preformed partition means made of a composition containing bituminous matter and fibers, .and a box body molded into connection with the said preformed partition means from unformed material also containing bituminous matter and fibers.

9. In a battery box having its box body molded from material containing bituminous matter, filler, and fibers, and separately formed partition means integrally connected at the edges to the interior wall of the box also made of material containing bituminous matter, filler, and fibers, the general direction of the fibers in the sides of the box being at an angle to the direction of the

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