US2290286A - Apparatus for cooling metal molds - Google Patents

Description

APPARATUS FOR COOLING METALMOLDS Filed May 10, 1940 4 Sheets-Sheet l INVENTORS 1221111 (1. Leafie Filed May 10, 1940 4 Sheets-Sheet 2 l INVENTORS .h/m 47- Laurie July 21, 1942. J. G. LEcKIE ETAL APPARATUS"FOR 000mm METAL moms 4 Sheets-Sheet 3 Filed May 10, 1940' July 21, 1942. J. G. LECKIE ETAL APPARATUS FOR COOLING METAL MOLDS Filed May 10, 1940 I 4 Shets-She'et 4" 2 1 .8 l w Km Mm A m Patented, July :21, 194 2 2,290.286 v A APPARATUS Fon cooLmG METAL MOLDS tion of New Jersey Application May 10, 1940, Serial No. 334,320 (01.22-1) 5 Claims.

The present invention relates to improvements in thermal conditioning of molds, and more particularly to an apparatus for applying controlled amounts of a cooling liquid to a heated mold to lower the temperature to a point such that when the mold wash is applied it will readily adhere and form a uniformly continuous coating film thereover.

In casting metals, for example copper, aluminum, etc., molten metal is poured into molds which have been previously coated with, a heat resisting coating; and the metal solidified forming billets. These billets are then removed from the molds and the molds recoated and used over again. During the casting process the molds become heated to a high temperature by the molten metal so that it is necessary to cool the molds after each use'before applying the mold wash in order to produce sound castings which can be.

readily removed from the mold.

Various methods and means have been utilized heretofore for attempting to effect rapid cooling of metal casting molds, but no simple, efiicient and economical way of accomplishing this has been devised. This is the principal object of the present invention.

A further object is to provide a machine which is operable to effect automatic cooling of the mold to the desired temperature between successive casting operations.

Briefly, the invention consists in providing an adjustable sprayer mechanism which is arranged to spray cooling water onto the hot' molds for a predetermined time limit to cool the molds to the optimum temperature required for producing sound castings. Means is provided for varying the duration of the spraying operation in accord- Y ance with the amount of heat to be dissipated.

A further object of the invention is to provide equipment of the above-indicated type wherein the spraying period is controlled automatically for a definite period of time, thereby assuring the same spraying time for each mold.

Further objects and advantages of the present invention will become apparent as the. description proceeds, and, the features of novelty will be pointed out in particularity in the appended claims.

The invention is illustrated by the accompanying drawings which show an adaptation of the invention wherein the molds are illustrated as being mounted on cars for being cooled by equipment embodying the features of the present in- 55 vention.

Referring more particularly to the drawings:

Fig. 1 represents a side. elevational view of a Fig. 1 showing a' mold car with molds mounted in position to receive cooling spray from the spray pipes, the view also showing certain details, partly diagrammatic, of the control mechanism for the spray.

Fig. 3 is a plan view of the spray piping for the installation of Figs. 1 and 2, mold cars being not shown.

Fig. 4 is a wiring diagram for the controls.

Fig. 5 is a diagrammatic representation of the hydraulic circuit for the illustrated equipment.

Fig. 6 is a perspective viewof certain details of a timing device which is suitable for use in connection with the present invention.

Fig. 7 is a view similar to Fig. 1 showing a modified form of connection for thepipe which supplies water to the spray chamber, whereby the spray water does not enter the valve.

Figure 8 is a view similar to Figure 5, showing the modified construction of the spray supply line as illustrated in Figure 7.

Referring more particularly to the drawings, the illustrated embodiment of the presentinvention comprises a spray chamber A, having a plurality of -spray-pipes B controlled by mechanism C, for spraying cooling water on molds D mounted on mold car E, and illustrated as billet molds.

The spray chamber illustrated in the drawings includes sides 1 and 9, which are steel plates spaced apart by cross-beams ll, l3, l5, I! which are welded to the side plates 1 and 9 and to vertical H-beams l9, of which four are shown on each side, these H-beams thereby reinforcing the side .plates as well as securing the cross-beams firmly in position. The spray chamber is open at the ends and top, a pipe 2! extending longitudinally of the chamber at the top thereof, andresting on at least some of the cross beams, the beams l3 and It being shown on the drawings as supporting the pipe 2! which leads to the spray pipes, which will be referred to hereinafter. The spray chamber A is shown as being erected-on a foundation 23, which may be of concrete, the bottom of which forms a bed for rails 25 of the track for the mold car E. The foundation 23 defines a pit 27, the bottom of which slopes downwardly to a water-return gutter 20, which will be referred to in greater detail hereinafter.

The pipe 29 receives water from-a pipe 3| and joins through a T-connection 33 to oppositely extending pipes 35 and 31 which are extended downwardly within the spray-chamber along the side walls thereof, and as is indicated at 39 and M in Figures 2 and '7. From these downwardly extending pipes there are extended horizontally similar groups of pipes indicated generally at 43 and 45 which are provided with spray nozzles 41, 49 which direct their spray on the molds; The horizontally extending spray pipes are closed at their ends by suitable cap means 46, as shown in Figures 1 and 3. A T connection 48 is used to join the pipes 3| and 2| together as illustrated in Figure 3.

Any suitable arrangement of the spray pipes and nozzles may be used for directing the cooling water against the molds, one embodiment being illustrated in Figures 1, 2, 3, and 7 of the drawings.

An important feature of the invention resides in the provision of adjustable automatic means for controlling the spraying operation which will now be described. This mechanism controls the flow of water to the spray chamber, for example,

' through pipe 3| to 2| and comprises a motor actuated valve 50, the operation of which is automatically controlled by an electrically actuated time switch means, such as diagrammatically illustrated in Figure 4.

A reversing motor 5| having field windings 53 and 55 is arranged to operate the valve 50 by means of the worm 51 mounted on the armature shaft of the motor 5|. Worm 51 drives the gear 6| in mesh therewith. Gear 6| operates a crank 63 which is connected to the valve operating lever 1I through the rod 61 as shown in Figure 2. When the gear 6| is rotated the valve actuating member 1| is swung to the right or left, depending upon the direction of rotation, about the pivot 12, as viewed in Figure-4, to control the flow of water to the spraying mechanism. The opposite end of the rod 61 is suitably shaped, as at 68 in Figure 4, to form a switch actuating member for the limit switch means 13.

This electrical switch mechanism comprises the contactor arm' members 11 and 19 which are pivoted as at 8| and 83. Electrical contact means 85 and 81 coact with the arm members 11 and 19 respectively to form an electrical circuit as illustrated in Figure 4.

For controlling the length of time the spraying means is in operation, a clocklike timing mechanism is utilized as diagrammatically shown in Figure 4. This mechanism is electrically connected to the limit switches 13 for controlling the operation of the motor 5|. A dial member 9| has graduated scale markings for indicating the duration of the spraying operation. Associated therewith is a manual adjusting means 93 which is adapted for setting the timing mechanism so that the spraying meanswill operate for a desired length of time and then be stopped. This adjusting means comprises a cam member 95 which is rotated by the motor 92 having the field windings 94 and connected to the power line 91 through leads 99 and 99.

The cam 95 is mounted on a suitable shaft 96, see Fig. 6, which extends through the housing 99 and which is rotated by-the motor 92 through suitable speed reducing means indicated by pinion 98 on the motor shaft 00 and gear I02 on the shaft 96. The manual adjustment 93 comprises a knob which is telescopically mounted on the time-adjusting end of the shaft 96. Spring means I04 compressed between the knob 93 and cam 95 normally holds the knob 93 in outward position. The knob 93 is provided with a gear I06 which meshes with dial 9|, this latter meshing also with an internal gear I08 on the adjusting cam 95, so that the dial 9| may be set to indicate the duration of the spraying period by pushing in on the knob 93 and turning the dial 9| and adjusting cam 95 to the desired predetermined time interval.

There is provided also on the shaft 96 a cutoff cam IIO for the motor 92, which operates a start-stop. switch II2 for starting and stopping the motor 92 as will be described hereinafter in greater detail, a, contact lug M4 on the cut-off cam I.I0 throwing switch 2 by engaging a contact lug II6 on the switch I I2.

The cam 95 is provided with a segmental lug IOI which is adapted to engage a contact I03 on a reversing switch I05, the switch I05 being adapted to operate between contacts I01 and I09 for operating the valve-actuating motor 5| in reverse direction. The switch I05is held by the pressure of a suitable spring (not shown) against contact I01, but when the segmental contact IN on the cam 95 engages contact I03 on-arm I05, the latter is depressed until it engages the contact I09 for reversing the motor 5| and consequently the actuation of valve 50.

A master control switch III, which conveniently is a push-button switch, is provided between the lead 99 for motor 92 and the line 91; a lead II 3 connecting the other side of switch III to the line. Since the switch III preferably is a push-button switch, it normally is open.

The start-and-stop switch II2 pivotally mounted as indicated at I24. and is urged normally against contact I26 of the motor 92, by the pressure of a suitable spring, not

shown. A lead I28, connected to lead 3 be-- tween the switch III and line 91 and to the switch II2, supplies sustaining current to the' motor 92, the current being returned to the line 91 from motor 92 through lead 99'.

The push-button III normally is open, as has been said above, so that when thelug 4 on cam IIO engages contact II6 on switch 2 to break the contact between the switch ,2 and motor contact 6, the motor 92 stops.

tact II6, thereby .allowing the switch II2 to make contact with the motor contact I126, so that when the push-button III is released, the motor 92 still operates by current supplied through lead I28 and switch I I2, the'motor 92 running until contact is made again between the cam contact H4 and switch contact 6, causing the disengagement of the switch 2 from contact I26, thereby stopping the motor 92, as pushbutton III normally is open, until the pushbutton III is closed again.

It will be understood of course that the time adjusting cam 95 is rotated with the shaft 96, through the medium of friction disc drive I30, see Fig. 6.

Now it will be observed from Fig. 4 that the push-button III is connected to the valve motor is suitably 5| by way of lead 99 and lead II5 which is connected to the lead 99. The valve motor field 55 is connected to contact 85 for arm 11 of limit switch 13 by a lead ||1,-another lead 9 connecting the limit switch arm 11, at its pivot point 8|, to contact I01 engaged by reversing switch I05, a lead I2I connecting this switch I05 to the other side of the line 91.

This constitutes the spraying circuit at the start of the timing motor 92. When this motor 92 starts and the switch I|2 has closed, the motor 5| operates independently of the pushbutton I I I as does the motor 92, the spraying circuit being then from line 91 through leads I I3, I28, switch H2, contact I26, lead 5 and then as described above.

Now the field 53 of the valve motor 5| is connected by lead 8 to the contact 81 for limit switch arm 19, this in turn being connected at its pivot point 83 through lead I20 with contact I09 for the reversing switch I05.

This constitutes the valve-opening circuit, which of course is completed by engagement of the segmented, contact on the time-adjusting cam 95 with the contact I03 on the switch I to depress the latter into engagement with contact I09.

The length of time of spraying 'is determined by' the position of the segment contact IOI on the cam 95 with respect to the contact I03 on the reversing switch I05. With the cam 95 being turned by its motor 92 in clockwise direction, the more nearly a complete revolution the cam 95 makes before contact IOI depressingly engages contact I03 of switch I05, the longer will be the spraying time. This position of the contact |0| relative to the contact I03 is adjusted by the manipulation of the knob 93.

In order to indicate when the sprays are operating, to an operator who may be at a station remote from the equipment, a signal light I22 is illustrated as being connected in the spraying circuit, the light continuing to glow while the spraying circuit is closed, and being extinguished when switch I05 leaves contact I01.

At the start of operation, with the adjusting cam 95 in proper position and the dial 9| is indicating the desired duration of spraying time, the elements of the mechanism will be in the position shown in Fig. 4.

Push-button III is closed momentarily, this momentary closing starting the valve motor 5| and the timing motor 92. The starting of the latter moves the contact |I4 out of engagement with contact I |6,,thereby allowing the switch NZ to close, rendering the-push-button I|| inactive and permitting it to open without stopping motor 92 which rotates the cams I I0 and 95. Meanwhile the motor 5| operates the worm 51 and gear BI, thereby causing the valve 50 to close, so that water is passed to the spray pipes by the action of pump I23 as will be described hereinafter.

As the valve 50 closes, the switch-actuating member 59 of rod 61 is approaching an abutment screw I25 mounted in the limit switch 13, con tinued movement of the member 69 towards the left as viewed in Fig. 4 will push against the tinuously, with the segment contact IN on cam l low the cams 95 and H0 aremtating conapproaching the contact I03 on switch I05, and the spray continues to be on until the see:- mental contact |0I engages the contact I03 and shifts the switch I05 from contact I01 into engagement with contact I09.

This reverses the valve-motor 5|, pulling back the switch actuator 68 and operating the lever 1| to open the valve 50. As the valve 50 is opened, the switch actuator 58 engages an abutment screw I21 mounted in limit switch 15, and presses thereupon until the contact is broken between switch arm 19 and contact 81.

Immediately thereafter the segmental contact has passed ofl from the contact I03, allowing the reversing switch I05 to snap back against contact I01, and lug I M of the cam ||0 engages contact IIS on switch I I2 to open the switch to stop motors 92 and 5| until the button I II is closed -to start the next cycle.

All switches preferably are spring-pressed, to assure positive action, and the abutment screws I25 and I21, being adjustable, assure proper contact of actuator 68 therewith, for assuring proper actuation of the limit switches by the actuator 68.

It has been found in practice that the molds should be cooled uniformly, and that, consequently, it, is important to maintain the spraying water at a substantially constant tempera-, ture. This will be brought out in greater detail hereinafter. v

It has been pointed out above herein that the spray chamber is built on a concrete foundation 23, the bottom of which slopes inwardly to a return gutter 28 which returns the water to a settling sump I29 the top of which is provided with an overflow |3| which leads into a pump sump I33, in which is positioned a pump I23 which continuously operates to circulate water by way of pipe I23 through the valve ,59 as illustrated in Figures 5 and 8. Suitable by-pass means I35 is provided for passing the water to the return gutter 29 while the valve 50 is opened.

The pump I23 is driven continuously by a motor I31. I

The pump sump I33 is provided with an overflow I 39 for passing excess water to a cooling pond or other storage I4 I. In practice, the water employed for coolng purposes is maintained at a temperature of from' sump I33, this being taken as the source of thecooling water.

The temperature control means are il=lustrat-- ed as comprising a steam supplyline I43 and a water supply line I45, these being valves I41 and I49 in the respective pipes for controlling admission of steam and water, respectively to the system, the steam being added to heat the Water, and Water being added for cooling. The

pipes I43 and I41 open substantially below the level of the water in the pump sump.

The valves I41 and I49 are operated manually asshown in the drawings. However, thermostatic controls operable by predetermined variations in the water temperature in the sump I33 may be provided readily for automatically maintaining a constant temperature in the circulating water. By virtue of the steam-line I43 and water line I45 the temperature of the circulating water may be maintained closely at any preselected temperature. Of course, suitable heating and cooling coils may be substituted for the pipes shown.

Make-up water may be admitted into the system through pipe I45 for maintaining the requisite volume of water in the system, in addition to providing for the introduction of cooling water into the system if the circulating water becomes too hot for the given operation. The excess water introduced either by the introduction of such water, or by the condensation of steam introduced into the system, overflows through overflow I39 into storage I4I A temperature indicator is provided to indicate the temperature of the water, the indica-. tor |5|. being operated by a suitable gas bulb I53 submerged in the water in the pump sump. Of course, when an automatic thermostatic control is provided for the control of the source of heat and cooling, the indicator |5I serves merely as a check on the proper operation of the thermostatic control. In the illustrated installation, the indicator I5I indicates to an operatorwhether steam or water is required to be introduced to maintain the desired even water temperature.

While the present invention has been illus-' trated and described specifically in connection with the cooling by spraying of meta1 billet molds employed in the casting of copper billets, it will be apparent that the principle of the present invention is not limited necessarily to this particular adaptation of the invention, as this same principle of controlled spraying time in conjunction with the maintenance of an even temperature of the spraying fluid is usable in a wide diversity of applications. For example, it may be applied to molds mounted on a casting wheel, or, in general, to any installation wherein there is needed an automatic timing control for effecting an adjustable predetermined time of contact between the. objects; and the fluid applied thereto, as well as for maintaining a predetermined scribed above.

It will be understood, of course, that in the embodiment of the invention as illustrated and described herein the valve 5|] may be a standard two-way valve operating so that when the valve is open to allow spray water'to pass through the pipe 3|, the by-pass line I35 is closed; and when the motor 5| reverses at the end of the spraying period the pipe 3| becomes closed and the by-pass line I35 becomes open, for continued circulation of the water. However, it will be understood that details of the system as illustrated may be modified without departing from the scope and spirit of the invention, as shown in Figs. 7 and 8. Thus, the pipe 3| may join the pump line in advance of the valve 50', as illustrated in Figures 7 and 8. Valve 50' may be a simple cut-off valve, to which the by-pass I35 is connected, the operation then being that when the motor 5| operates the valve to close it in the manner as described above, water will pass through pipe 3| to the spray chamber, and when the motor 5| reverses at its end of the spray period as described above to open the valve, the water is prevented from flowing through pipe 31, which is a vertical pipe,.and passes through the relatively short by-pass I35 andthence back to the pump sump I33. In this arrangement of the equipment the water will not pass into the valve 50' on its way to the spray chamber, but other- .wise the actuation of the various elements of the system will be the same as has been described above in detail.

What is claimed is: 1. An apparatus for cooling molds to a predetermined temperature comprising the combi- 'a pivoted lever for opening and closing said constant temperature of the applied fluid, as de-' valve, a motor for actuating said lever, said motor being reversible to move, said lever in either direction to operate said valve, adjustable timing mechanism operatively connected to said motor for operating said valve so as to apply cooling liquid directly onto said molds for a predetermined length of time, and then automatically bring about the actuation of said valve to cut off the application of cooling liquid to-the molds. v

2. Apparatus for-cooling metal casting molds which comprises the combination with a spray chamber having means for positioning the molds to be cooled therein, of a conduit. for passing cooling fluid into said chamber and directing it in the form of a spray onto said molds to cool the same, valve means in said conduit, means for controlling the operation of said valve to allow cooling fluid to pass to said spray chamber for a predetermined time, and means automatically operable after the expiration of said predetermined period of time to cut off the flow of liquid to the spray chamber, and means for maintaining the cooling fluidat a substantially constant predetermined temperature to effect uniform cooling of the molds.

3. Apparatus for cooling metal casting molds which comprises in combination with a spray chamber and means for moving mold means to be sprayed therethrough, of a conduit for passing cooling liquid from a source of supply to said spray chamber, valve means positioned in said conduit for controlling the flow of liquid to the spray chamber, means comprising a reciprocable lever for operating said valve to control the flow of cooling liquid, time-setting switch mechanism for operating said valve to effect spraying of said mold means for a predetermined period of time and then cut off the spray by diverting the flow of liquid cfrom the spray chamber back to the source of supply, means for continuously circulating the cooling liquid from the source through said conduit, said means including a by -pass controlled by said valve operable to allow I said cooling liquid to pass back to said'source' ply and pipe connections to said chamber for conducting cooling water thereto, valve means 1n said pipe ior controlling the flow of water to said spray chamber, mechanism comprising a reciprocable means tor operating said control valve, prime mover means operatively connected to said reciprocable means for intermittently moving it from one position to another, adjustable time switch means associated therewith for starting said prime mover to bring about the shifting of said reciprocable means to operate said valve and cause water to pass to said spray chamber and .be sprayed on the molds positioned therein, said reciprocable means being actuated by said prime mover after a predetermined time interval corresponding to the setting of said.

time switch to stop passage of cooling water to said spray chamber and onto said molds.

5. An apparatus for cooling molds comprising a sprayer mechanism, a source of water supply, conduit means connecting said water supply and sprayer mechanism through which cooling waspr-aying position at the end of a predetermined time interval during which said valve has been set in the spraying position, means for adjusting said .time switch mechanism to vary the duration of the spraying operatiomand means for maintaining said water supply at a substantially constant temperature to effect uniform 15 cooling of the molds.

JOHN G. LECKI'EL' ARNOLD J. KLEFF, JR.

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