US3072774A - Mat processing equipment - Google Patents

Description

Jan; 8, 1963 c. T. LARSEN ETAL 3,072,774

m PROCESSING EQUIPMENT Filed Jan. 18. 1960 2 Sheets-Sheet 1 INVENTORS CHARLES T. LARSEN DAVID 0. Mc GRAW ATTORNEYS Jan. 8, 1963 c. 'r. LARSEN ETAL 3,072,774

mxr PROCESSiNG EQUIPMENT Filed Jan. 18, 1960 -2 SheetS-Sheet 2 FIGS. FIG-7- FIG5." FIGJO.

as Hf PS 8 TIMER u FIG. I I. DAVID cmc GRAW hired This invention relates to newspaper matrix (hereafter called mat) processing equipment, and more particularly to an improved stereotype mat scorcher or roaster.

The newspaper industry operates in a complex series of deadlines and practically all operations'in the publishing of a newspaper are carried'out 'on a tight time schedule. Much duplication of machinery is necessary'to assure the rigid time schedule is met since a failure of any one of the machines which are links in the chain of operations in the printing of a paper will stop the entire operation. One of the critical steps in the process is the preparation of the stereotype mats from which printing castingsare made of a lead alloy hereafter called stereotype metal.

A stereotype mat before processing is a flat laminated sheet of papier ma-che-like material inclusive of a substantial moisture content to better enable it toreceive and retain a-n'impression from an assembled and completed printers form. The actual impression is made by passing the mat in association with the printers form through a press under a sufiicient pressure to produce a clear impression. Subsequently the mat is pretreated in a vacuum drier and has a curved configuration imparted to it. next steps are directed towards forming a stereotype metal casting from the mat. In order to make a good casting it is necessary'that the mat be completely dry and'uniformly heated to a temperature compatible with molten stereotype metal. This is accomplished by a scorcher.

It is necessary that the mats treated on a scorcher produce clear, precise, and exact castings so that there will be sharp reproduction in printing. Areas of partieular difficulty are photographs, comic strips, illustrations and the .like, which in the trade are termed half-tones.

Present commercially available scorchers'have a tend ency to produce a nonuniform temperature gradient across the mats. Mat temperatures processed by such equipment will vary'fro-m relative coolness near the edges to higher temperatures towards the center.

' Furthermore, the present commercially used scorchers require long period-s of time, up to about forty minutes, to preheat to initial operating conditions of about 350 F. These scorchers use 'strlp heaterslas a heat source and are usually thermostatically controlled. 7 With thermostatically controlled scorchers there is normally a. wide variance from high to low temperature. Strip heaters are fiat, tube-"like sheaths encompassing a metallic electrical resistance element packed in a high melting point sand or powder such as TiO perature, the thermostatic control stops the flow of electricity and'the temperature starts to drop due to a convection effect resulting from the passage of air around the strips. Inforder to maintain the desired temperature the thermostat causes a repassage of current through the strips. Since these strip heaters are slowheating and cooling elements, the continual. re-occurrence of these actions results in the above-mentioned variance in temperature-s.

As pointed out before, it takes approximately forty minutes for a scorcher using strip heaters to reach the initial operating temperature ofabout 350 F.; and after the treatment of one mat, a recovery time is required before a subsequent mat may be treated.

The problems discussed above are undesirable in that a temperature gradient results in poor mats, i.e., not uni- The v Upon reaching the desired teming and/or area coolness.

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formly heated across their surfaces, and castings made from such mats haveaporous, mottled and congealed surface. If a casting with these surface characteristics is usedon the presses, blots and masses of ink result rather than the precise and sharp reproduction desired.

Also, in treating a stereotype mat in strip heater type scorchers, when the mats. reach a point where further eating may cause area burning, they must then be removed'and because of the frequent uneven roasting of the mat, there may still be moisture present. When the mat contains moisture, contact with molten stereotype metal may cause rather violent steam explosions, resulting in spraying of molten metal, endangering personnel working with the mats.

Thus, where the first heat treatment results in an improperly conditioned mat producing a chilled casting, having a porous, mottled and congealed surface, it has to be thrown away and a new one made, resulting in delay and lost production time. If this second or third casting is also faulty, the lost time increases. If an imperfect mat cannot produce a satisfactory casting, then a new stereo-- type mat would have to be made with a resultant time consuming and expensive delayin making the casting.

Recently in the newspaper industry, there has been developed what is termed no-pack stereotype mats. These mats are about one-eighth of an inchin thickness and consist of a plurality of paper lamina inclusive of clay filler and moisture. With this new relatively thick mat and present strip heater type scorchers, it is necessary that heat be imparted to the mat at a relatively slow rate to dry the mat throughout itsthickness and to prevent burn- Using the strip heater type scorcher it takes over four minutes to properly condition and treat a no-pack mat. invention, it is possible to treat such mats in from thirty to sixty seconds.

Comparing the prior trade scorchers and the problems encountered in their use with a scorcher according to our invention; it is possible to reach initial operating conditions with our scorcher within about five minutes of the.

it is possible to allow a mat to remain in the device without danger of burning; there is a thorough drying throughout the thickness of the mat eliminating the possibility of steam explosions; and there is an even heating over the entire surface, eliminating area chilling of casting and/ or burning-of mats.

I Briefly, our invention consists of the use of a plurality of series of tubular quartz lamps as infra-red ray emitters better described as an incandescent element enclosed in an'evacuated tubular glass sheath, reflectors, a suitable housing, and surface upon which a mat may be placed. The foregoing, in combination with a timing device, will enable those skilled in the trade to overcome the previously noted shortcomings of present commercially used scorchers in a manner which will become more obvious from the description presented hereafter.

It is, therefore, among the objects and advantages of our invention to provide an improved newspaper stereotype mat scorcher which uniformly itreats such mats both across their surfaces and through their thicknesses; and accomplishes a superior treatment in a greatly decreased period of time than previously thought possible; and requires substantially no recovery time after each use;

Other objects and advantages will become obvious from a study of the description hereafter with reference to the appended exemplary drawings, in which:

FIG. 1 is an end elevation in partial section of .a scorcher according to our invention;

FIG. 2 is atop view of an arrangement of tubular infra With adevice according to our.

FIG. 3 is an end detail of the device of FIG. 1;

FIG. 4 is an end detail of the device of FIG. 1 with the cover partially open;

FIG. 5 is a side view of the device of FIG. 1 with the cover sectioned;

FIGS. 6l0 are details of the timer activating mechanism from on through off positions in its operating cycle;

FIG. 11 is a wiring diagram of the device of FIG. 1; and

FIG. 12 is an enlarged detail of FIG. 2.

FIG. 1 which shows an exemplary scorcher design according to our invention depicts a suitable floor supported frame which includes a power supply 11, magnetic switch 12, timer mechanism 13 and mat treating area 14 at a readily accessible working level.

The infra-red ray emitters 15 are heldin spaced position by such as supports above the reflectors 21 and 22 (better shown in FIG. 2) and base member 32. An arched surface 23, preferably made of perforated sheet metal, supports a sheet of asbestos 24 (better shown in FIGS. 3 and 4) whereupon stereotype mats (not shown) may be placed for treatment. A cover 25, pivotally held in position by the rod 26, internally carries a second sheet of asbestos 27. The cover is easily lifted by means such as handle 28. The lifting operation is aided by such as counterweight 99. Depending from the counterweight is a support 35 carrying a cam 36 which is positioned to depress the timer actuating button 37.

The placement of the infra-red ray emitters 15 is shown in FIG. 2 as consisting of three series of two each, positioned above the reflectors 21 and 22. Preferably the reflectors are made from corrugated, polished sheet metal. Because the elongated tubular design of the infra-red emitters, rays are propagated around a 360 angle, the reflectors are spaced beneath the emitters a distance suflicient to assure substantially complete reflection of the downwardly directed rays upwardly through the mat being treated. Also, because of the 360 ray propagation configuration, in combination with the reflectors, it is possible to use a planar arrangement as opposed to an arched mounting, close to the mat holding surface, as required with use of strip heaters.

The schematic wiring diagram of FIG. 11 shows power being supplied at all times, when the device is on, to the two center emitters, a, b, while current to the other four emitters is controlled by the action of the magnetic switch 12 in conjunction with timer 13.

FIGS. 6-10 are illustrative of the cycle of operation by which when the cam 36 is allowed to pass the timer actuating button, when the cover is opened without depressing the button, and upon closing of the cover, the cam is locked against the bumper 38 and caused to depress the button 37 thereby causing a surge of electricity to pass to the outside emitters thereby raising the temperature in a manner that will be described in detail hereafter.

Operation The power source is connected to a suitable supply of electric current (not shown) by such as plug 34. Upon closing of switch 33 the device is turned on causing the center emitters a, b, to be activated. After the device reaches an operating temperature of about 270 F., a peri 0d of about five minutes, a stereotype mat to be treated is placed on the asbestos sheet 24. The cover 25 and the surface 23 and the asbestos sheets 24 and 27 carried thereby, respectively, are shaped to conform to the normal shaping of the stereotype mats and spaced apart sufficiently to allow a firm pressure to be uniformly exerted over the surface of a mat placed between them.

After placement of the mat, the cover is closed. As the coveris lowered the counterweight moves the support and cam 36 across the activating button 37 thus closing the circuit to the four outside emitters and starting the timer. A surge of about ten seconds duration to the outside emitters causes the temperature to rise about 60 F. over a period of about thirty seconds thereby gradually raising the temperature from 270 F. to about 330 F. Thereafter there is a gradual cooling back to the standby temperature of 270 F. A mat has been left in a scorcher according to our invention as long as five minutes without burning, which is one of the desirable safety factors achieved by our scorcher which was not obtainable in the present commercially available strip heater type scorchers discussed previously.

After the thirty-second heat treatment, the mat is removed and is used to form one side of a mold for a stereotype metal casting and another mat may be heated immediately, no recovery time being necessary.

The strip heater type scorchers discussed above have no operation similar to our ten-second surge period; take at least seventy seconds to heat the first mat, require one-half to two minutes before subsequent mats may be treated in addition to the seventy-second period for actual treatment, and have a fixed temperature level which requires constant supervision to prevent burning of the mats.

Stereotype mats for comic strips have been a particular problem with the strip heatertype scorcher since comic mats are thinner and more diflicult to cast and are only cast once, multiple castings being unnecessary. Our scorcher will condition a comic mat in about forty seconds.

Another feature of a scorcher according to our invention is that the timer may be correlated with the speed, skill and efiiciency with which the man using its is able to Work.

It is anticipated, of course, that other arrangements of emitters than those shown in our exemplary arrangement may be used which would accomplish our invention such as, for example, three elongated emitters.

Having described one manner of practicing our invention, it is desired that it be understood that we do not desire to be limited to the particular design set forth herein, but rather by the scope of the appended claims.

We claim:

1. A newspaper stereotype mat scorcher inclusive of a base member having means for reflecting infra-red rays directed toward the base toward a mat supporting surface and a mat carried thereby, a plurality of series of elongated tubular infra-red ray emitters supported on said base member spaced above said reflecting means, mechanically operable switch means associated with the scorcher arranged to periodically activate some of the series of emitters and means arranged to provide continuous activation for the remainder, and timing means interconnected with said switch means arranged to periodically automatically activate only said some of the series through predetermined time intervals upon initiation of the scorching of a mat.

2. A newspaper stereotype mat scorcher inclusive of a base member having means for reflecting infra-red rays directed toward the base toward a mat-supporting surface and a mat carried thereby, a plurality of elongated tubular infra-red ray emitters supported on said base member spaced above said reflecting means, means arranged to provide continuous activation of a portion of the emitters, and second means inclusive of timing means for periodically activating only the remaining emitters through predetermined time intervals upon initiation of the scorching of a mat.

3. A newspaper stereotype mat scorcher inclusive of a base carrying means having a substantially planar upper reflecting surface arranged to reflect infra-red rays directed toward the base toward a supporting surface and a mat carried thereby, a cover supported on the base member arranged to be positioned in close proximity to the mat supporting surface upon closure, a plurality of elongated tubular infra-red ray emitters supported on said base member spaced above said reflecting means, and

-on said frame above said working surface, the working surface and cover having opposed heat resistant surfacing and shaped to'hold a stereotype mat under uniform pressure across its surface, the plurality of series of emitters being spaced above a reflecting surface and supported by said frame, at least one series of emitters continuously in closed circuit relative to the power source and the remaining of the plurality of series of emitters in circuit with the magnetic switch and the timer as well as the power source such that the activation of the timer closes the magnetic switch and thus completes a circuit whereby the other series of emitters are activated for a period of time determined by the timer setting and thereafter the circuit is broken, and means to activate the timer mount ed on the cover. 1 p

5. The apparatus of claim 4 in which the emitters are elongated, air tight, evacuated, tubular transparent sheaths enclosing elongated incandescent type elements capable of propagating infra-red rays radially through an angle of 360.

6. In a newspaper stereotype matscorcher inclusive of an'arcuate working surface arranged for registry of a similarly shaped stereotype mat'to be scorched and a movable cover therefor which conforms in shape to the working surface, the improvement which comprises a plurality of elongated, air tight, evacuated, tubular transparent sheaths each enclosing at least one elongated incandescent-type element capable of propagation infra-red rays through an angle of 360 through the sheath relative to its longitudinal axis, all of said emitters being spacedly supported above a planar reflecting surface below the working surface whereby said infra-red rays propagated 6' through an angle of 360 are substantially all directed through the working surface and a matfcarried thereby, means interconnected with at least some of the emitters arranged to be activated upon closing of the cover to temporarily activate the emitters with which it is interconnected.

7. A newspaper mat scorcher comprising a frame, a power source, switch means and a timer all mounted on said frame, a plurality of series of elongated tubular infrared ray emitters mounted on said frame below a working surface supported thereby, and a cover mounted on said frame above said working surface, the working surface and the cover having opposed heat resistant surfaces and a shaped to hold a stereotype mat under a uniform pressure across its surface, the plurality of series of emitters being spaced above a reflecting surface and supported by said frame, at least one series of emitters continuously in closed circuit relative to the power source and the remaining of the plurality of series of emitters in circuit with the switch means and the timer as well as the power source such that the activation of the timer closes the switch means and completes a circuit whereby the other series of emitters are activated for a period of time determined by the timer setting and thereafter the circuit is broken, and means to activate the timer operatively interconnected with the cover.

References Cited in the file of this patent UNITED STATES PATENTS 1,135,473 Vath Apr. 13, 1915 2,454,334 Moir Nov. 23, 1948 2,535,268 Coats Dec. 26, 1950 2,542,654 Gadden Feb. 20, 1951 2,612,594 Schubert et a1 Sept. 30, 1952 2,731,733 Griner Jan. 24, 1956 2,919,119 Vyverberg et al, Dec. 29, 1959 2,935,594 Christenson May 3, 1960 2,957,973 Torrez Oct. 25, 1960 FOREIGN PATENTS 738,031 Great Britain Oct. 5, 1955

Claims (1)

1. 3. A NEWSPAPER STEREOTYPE MAT SCORCHER INCLUSIVE OF A BASE CARRYING MEANS HAVING A SUBSTANTIALLY PLANAR UPPER REFLECTING SURFACE ARRANGED TO REFLECT INFRA-RED RAYS DIRECTED TOWARD THE BASE TOWARD A SUPPORTING SURFACE AND A MAT CARRIED THEREBY, A COVER SUPPORTED ON THE BASE MEMBER ARRANGED TO BE POSITIONED IN CLOSE PROXIMITY TO THE MAT SUPPORTING SURFACE UPON CLOSURE, A PLURALITY OF ELONGATED TUBULAR INFRA-RED RAY EMITTERS SUPPORTED ON SAID BASE MEMBER SPACED ABOVE SAID REFLECTING MEANS, AND MEANS ARRANGED TO PROVIDE CONTINUOUS ACTIVATION TO AT LEAST ONE SERIES OF EMITTERS, SECOND MEANS FOR AUTOMATICALLY ACTIVATING THE REMAINING EMITTERS THROUGH PREDETERMINED TIME INTERVALS, AND MEANS CARRIED ON SAID COVER ARRANGED TO ACTIVATE THE SECOND MEANS.

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