US1368445A - Storage-battery-grid mold and molding process - Google Patents

Description

I. B LITTLE.

STORAGE BATTERY 681D MOLD AND MOLDING PROCESS APPUCAUUN man SEPIZ3, 1920.

.lfrz-verzZvr, 1'11: .521 ,9)" am Patented Feb. 15, 1921.

UNITED STATES PATENT OFFICE.

IRA. 13. LITTLE, 0F INDIANAPOLIS, INDIANA.

Specification of Letters Patent.

Patented Feb. 15, 1921.

Application filed September 3, 1920. Serial No. 407,808.

To all'whom it may concern. D

Be it known that 1, 11m 13. LITTLE, a citi- 'zen of the United States, residing at Indianapolis in the count of Marion and State of fndiana, have invented new and useful Improvements in Storage-l3attery- Grid Molds and Molding Processes, of which the following is a specification.

In the casting of storage batteries much loss and waste has been experienced because of the formation of air holes in the frame members of the grid OJEOSltB the gate, due lar ely to the partial lling of that portion of t ie mold by metal flowipg through the middle transverse frame members and reaching the far side of the mold before the air in advance of the metal forming the bottom transverse frame member can fill the latter and rise in the far side of the mold to the level of said middle transverse member. Under the conditions stated it will readily be seen that the air thns'cut off from escape willrcmain to form pockets and air-holes thereby rendering the nished product defective and worthless.

Obviously, the grid-mold must fill from the bottom, up, and all of the comparatively small passages in which the web is formed niust be progressively filled in order to avoid air pockets in them. An appreciable length of time is required for the metal to flow from the gate through the small passages of the web and, to keep the fluid metal at a proper temperature so it will not crystallize, and also to provide storage for excess metal coming through the lower passages of the mold w ile the upper ones are being filled, has beennecessary in common practice to pro- 7 Wide ariser of considerably larger capacity than-the channel in which the vertical frame member farthest from 'the gate is formed, and this riser-has heretofore can of uniform width and other dimensions from top to bottom, defined by a score line in the same manner as the vertical frame member on the gate side is defined from the gate. But the mold thus formed has resulted in a continuplication of my invention,

one loss of approximately forty per cent. of output. Many su gestions and experiments in mold-construction have been tried, but without any beneficial results until the apwhich has entirely overcome the difficulty, manufacture of over ahundred thousand grids'with my invention, every one has been double lead grids for trimmed.

so that in the commercially perfect and the former loss has been entirely eliminated.

The object of my invention is to provide a method to cause all of the vertical channels of the mold to fill sufficiently in advance of successive upper horizontal channels to avoid the tra ping of air and formation of air holes in t e vertical channels.

Another oby'ect is gradually to reduce the capacit of tie riser from a maximum at a suita 1c distance above the middle horizontal frame channel to such a suitable minimum at its lower end that the riser will take care of all of the surplus metal and fill to and above said middle channel before the metal coming in from the other end fills said middle channel.

The object also is to reduce the vertical line of communication between the riser and adjacent vertical frame channel to so narrow a dimension that there is not enough room therein for the formation of objectionable air pockets.

I accomplish the above, and other objects which will hereinafter appear, by the mechanism illustrated in the accompanying drawing, in which- F igure 1, is a view in side elevation of the upper part of a molding table with the molds and their appurtenances assembled in operative closed )osition. Fi 2 is an inside view of one half of a mo d embodying my invention. Fig. 3, is a transverse section of the complete mold on the line 3-3 of Fig. 2. Fig. 4 is a side view of a casting as it comes from the mold, and before it is grids, and Fig. 6, is a section on the line 6-6, of Fig. 4. I Like characters of reference indicate like parts in the several views of the drawing. In the drawing, Fig. 1, 7 is a table to which a'standard 8 is bolted, and to which standard the fixed half 9 of the mold is attached. The movable half 10 of the mold is secured to a member 11, hinged at 13 to 9. depending portion 12 of the standard. The two parts of themold are forced together by a screw adjustment shown in dotted lines 14, and. the mold is opened by grasping handle 14" and swinging on hinge 13 after the pressure is released.

As the chan'nelsfor grid are the same in both mold-halves 9 and 10, except in correspondingly reversed orthe forming of the der, a description of one will sufiice for both. it being understood that only halt of a gridforming channel isin each half of the mold.

It will be noted in Fig. 2. that two grids of the form of the finished casting shown in Fig. 5, are cast. at one time: also that their abutting frame members in the mold on the line 3-3, make a channel of double size which heretofore has filled its entire length and part way down the frame channel 15. before the metal coming through the frame channel 16 and horizontal web channels 17, have been able to tiIlt'lIaIIneI 15 and connected riser 18. The riser 18 is required. not only to provide storage for excess metal. but more in order to keep the frame formed in channel 15, from cooling to a degree that causes or stallization and weakening of the frame. se arate the riser from the adjacent frame y a channel 19 less than half the thickness of the riser. as shown in Fig. 3, which makes a finisher] web as shown in Fig. 6, through which the riser is cut from the grids close to the latter, and so narrow that there is not room enough for the formation of objectionable air holes to mar the ad'acent frame of the grid.

'lhe dotted lines at the lower portion of riser 18 in Fig. 2, show the extent of the riser channel as same has been heretofore made, and my invention in part. consists in reducing the area of the riser to a minimum of less than half the former width at the bottom, and in gradually tapering the riser to the former maximum width at an appreciable distance above the line of the channel 15.

The shape, size and location of the gate channel 20, is as usual, and in the finished casting the gate-portion is defined from the frame of the grid by a score 21, as a guide in trimming the product.

In the operation of my invention, after the two parts of a mold are closed together, the interference from warping being minimized by recessing the adjacent faces at 22. the molten lead is poured in through the. gate channel 20 and begins to till the mold channels from the bottom. The melted metal flows through the horizontal channels into the vertical frame channel 15, and into the riser 18. From thence to completion, the channels havegmple air outlet, and thus the entire casting is made without danger of the confinement of' the air that was in them, to form air-holes in the product. The riser channel affords such storage of hot metal in communication with the adjacent vertical frame members-through the restricted channel 19, that improper crystallization prevented, and the web formed in 19 is so thin that when out through in trimmingoff the surplus metal concealed air holes thus opened cannot be of any material size.

Having thus fully described my invention, what I claim as new and wish to secure by Letters Patent, is

l. The herein-ilescrihed method of casting battery grids in vertical molds having vertical channels and horizontal channels connecting the vertical ones, consisting in sup )lying the melted metal to the bottom of the mold. and lilling the vertical channels of the mold sulliciently in advance of successive upper horizontal channels to avoid trapping air and the formation of air holes in the channels.

2. The herein-described method of casting double battery grids in vertical molds having vertical channels and horizontal channels one of the lattcr of which at the junction of the two grid'molds is of double capacity to form frame-members for two grids. con sisting in supplying the melted metal to the bottom of the mold. and filling all of the vertical channels of the mold to the level of said channel of double capacity before the latter channel fills, whereby the trapping of air and formation of air-holes in the casting is avoided.

3. In a mold for casting battery grids said mold having vertical channels and horizontal channels connecting the vertical ones. gate means extending to the bottom of the mold, and a riser of gradually downward reduced area adjacent the far vertical frame member from the gate. f

4. The. herein described mold for casting. battery grids having vertical channelsland horizontal channels connecting the vertical ones, gate means extending to the bottom of the mold, a riser of gradually reduced area tltljtlwllt the far vertical frame member from the gate connected with said frame by a channel the dimension of which trans versely of the mold is less than half that of the adjacent frame member.

5. In a double grid-mold having a double frame channel at the junction of the two grids, a riser having a downwardly tapermg lower end which taper begins approximate] opposite said douhle frame channel.

6. n a double grid-mold having a double frame channel at the junction of the two grids, a riser having a downwardly tapering lowerend which taper begins approximatch opposite said double frame channel and it channed connecting the riser with the mold the dimension of the channel being less than half of the corresponding dimension of the Signed at Indianapolis, Indiana, this the 28th day of August, 1920.

IRA B. LITTLE.

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