US373001A

US373001A - zeidlee

Info

Publication number: US373001A
Authority: US
Publication date: 1887-11-08
Anticipated expiration: 1904-11-08

Description

(No Model.) 2 Sheets--Sheet 1. W. G. ZEIDLBR.

APPLYING UELLULOID T0 ORGAN KEY BOARDS.

- No. 373,001. Patented Nov. 8, 1887.

"W -www- 2 Sheets-Sheet 2. W. O. ZEIDLER.

APPLYING GELLULOID T0 ORGAN KEY BOARDS.

Patented Nov. 8, 1887.

UNITED STATES PATENT OFFICE.

' WILLIAM CARL ZEIDLEB, OF TORONTO, ONTARIO, CANADA, ASSIGNOB TO AUGUSTUS NEIVELL & 00., OF CHICAGO, ILLINOIS.

APPLYING CELLULOID TO ORGAN KEY-BOARDS.

SPECIFICATION forming part of Letters Patent No. 373,001, dated November 8, 1887.

' Application filed January 28, 1887. Serial No. 225,754. (No model.)

J all w/tom it may concern.-

Be it known that I, WILLIAM CARL ZEID- LER, a subject of the Queen of Great Britain, residing at Toronto, in the county of York and Province of Ontario, Dominion of Canada, have invented certain new and useful Improvements in Applying Celluloid to Organ Key- Boards and other Articles; and I do hereby declare the following to be a full, clear, and

to exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked there- 1 on, which form a part of this specification.

This invention relates to methods of mounting sheets of celluloid upon other materials, and to polishing the outer surface of such sheets of celluloid during the operation of mounting them, and it has special reference to the applying of sheets of celluloid to wood and to the simultaneous polishing and mounting of sheets of celluloid upon wooden orga and piano key-board blanks. The term celluloid is used herein to designate generically celluloid proper, zylonite, chrolithium, pyroxyline, and other substances allied to celluloid proper.

It is already known to the art that celluloid, by reason ofthe camphor incorporated with it, may be rendered plastic, or even pasty or semi-liquid, by subjecting it to heat, and that it'may be hardened again by allowing it to cool, and that by the application of great pressure sheets of the celluloid so made plastic or pasty may be partially pressed into the surface of certain materials to cause them to adhere to such surface. It is also known that the surface of a sheet of celluloid may be polo ished by pressing upon it a heated polished surface of hard material. This may be accomplished by the application of only a moderate degree of pressure and heat. Fifty pounds of pressure to the square inch and 250 Fahrenheit have been found sufficient. These two processes have been performed in one operationto wit, by placing a sheet of cloth or paper and a small thin paper-like sheet of celluloid in faeeto-face contact between the plates of a hydraulic press, the plate next the celluloid being polished and hollow, and steam being introduced into said hollow plate to heat it and cause it to soften the celluloid. On the application of the heat and pressure the surface of the celluloid in contact with the polv ished plate becomes soft and conforms to the polished surface. As the sheet of celluloid is thin, it becomes thoroughly plastic throughout its entire thickness. IVhile in this condi tion the pressure of the plates unites the cel- 6o luloid with the paper or cloth. The amount of pressure required to produce such union is,

h owever, very greatso great that only pieces of celluloid of limited size can be thus combined even with cloth or paper, for the reason 6 5 that it is impracticable to apply the requisite pressure to relatively large sheets, and so great that sheets of celluloid cannot be thus mounted on wood, for the reason that the enormous pressure would compress and crush the wood and render it useless.

All woods, and particularly thelight woods, are more or lessinjured when subjected to even more than a moderate pressure. In the manufacture of key-boards, when excessive pressure is applied, the wood is compressed, and in most cases afterward expanded or restored by absorption of moisture. As each board varies more or less in its cell-structure throughout its length, some portions are fully restored to their original thickness,while others are not. This, it will be seen, causes an uneven surface in the key-boards-a defect which renders them unfit for the market. As most of the key-board blanks are made by gluing smaller pieces together at their meeting edges to make the required size, it follows from this cause, if from no other, that the blank is of uneven density.

As an illustration of the great pressure re- 0 quired to unite the celluloid to other bodies, it may be stated that a piece of celluloid may be placed upon a larger piece of wooden board and pressed into the latter by a heated plate until the upper surface of the celluloid and 5 the surrounding surface of the board are on the same level, yet the celluloid may be readily pulled from the wood after the plate has been removed.

While my process is adapted to apply sheets :00

of celluloid to wooden articles other than keyboards, I deem it sufficient to illustrate the process by setting forth its use in the manufacture of key-boards.

The method heretofore practiced in mounting celluloid upon key-boards is as follows: A blank board of suitable size and shape to form a set ofkeys having been fitted to aframe bored, mortised, bushed 850., a narrow strip of celluloid, which is to constitute the polished front of the keys,is cemented to its front edge. This step is followed by a delay of several days to allow the cement and the celluloid, which has been softened by the alcohol in the cement, to become dry and hard. This front is then scraped and polished, and the top sheet of celluloid is thereafter in like manner cemented to the top of the board. This step is also followed by a long delay for drying and hardening. Next comes the scraping of the top sh eet-an arduous and careful hand task then the polishing,which, although performed by the aid of machinery, requires skill, time, and strengtlnbeside the employment of aquantity of pumice-stone. A large portion of the polishing material is wasted by being thrown off by the motion of the machine. As the pumice-stoneis used with water,the key-board becomes wet and swollen at the rear of the celluloid, the water often reaching and entering the back mortises and closing them tightly upon the pins, in which case it is necessary to ease them again with a handfile, and some portion of the mud of pumice-stone and water is also left by the polisher to dry upon the wood part of the key-board, which it is necessary to remove before the keys are separated. The scraping, filing of the mortises, and cleaning the board is done by hand, and the polishing, although done by a machine, requires muscle and brain as well. Moreover, according to this method, from twenty to thirty days are required for drying,hardening, and setting of the celluloid firmly upon the wood.

The extra labor and waste are a serious item in the cost of keys, and the unavoidable delay for the drying and hardening often causes great loss and annoyance to the organ and piano business. Special sizes and patterns of keys are often ordered for organs, in which case a month is required to fill such orders. The manufacturers of keys must also keep a months supply in the works to enable them to fill orders promptly. Even after waiting the length of time mentioned, the cementand celluloid are not always thoroughly dry and hardened. Often after the boards have been shipped to customers it is found that a slight excess of cement pressed into t0ol-creases or soft spots or streaks in the surface of the wood will dry and contract further and draw the celluloid over such places closer to the wood and out of the general plane of the celluloid, thus creating a defect which causes the purchaser to feel wronged.

By my improved method I am enabled to mount sheets of celluloid upon wood and other bodies which are destructiblc under great pressure and polish the outer surface of the celluloid by a single short operation. This has not to my knowledge been heretofore accomplished.

Heretofore manufacturers have been unable to mount sheets of celluloid upon key-board blanks and polish them by one and the same operation. By my improved method the entire work of mounting, polishing, and drying preparatory to sawing the board into keys may be performed in from five to ten minutes of time.

In the accompanying drawings, Figure 1 is a view of a form of press which may be used for my purpose. Fig. 2 shows a portion of a key-board blank and a sheet of celluloid to be applied to such board. Fig. 3 is an enlarged sectional View of the celluloid and a portion of the board and heated metal plate.

In the drawings, A representsahollow bedplate of the press; B, the ordinary movable head or platen; O, the screw,which is provided with a handle, D. A steam-pipe, E, leads into the hollow plate A, and a water-pipe, F, also leads into the interior of said plate. G is a pipe for the escape of steam and water from the hollow plate A. Suitable cocks are provided for each of these pipes. The upper surface of the plate A is made of steel, brass, or some other hard material capable of receiving a high polish, it being important that its surface he very true and highly polished, as any blemish in the surface of the plate would be imparted to the surface of the celluloid lying in contact with it.

The operation is as follows: The sheet of celluloid, H, is relieved of any foreign matter adhering to the surface which is to be polished, and any over-rough places are reduced. This is done by scraping or washing. Then the other side of the sheet (that which is to be next the board) is covered with liquid shellac, celluloid cement, (celluloid dissolved in alcohol,) or some other adhesive containing an alcoholic solvent of celluloid. By the time the heat is turned on the alcohol in the liquid adhesive applied to the upper surface of the celluloid has somewhat softened the said surface, but since alcohol is a latent solvent of the celluloid (that is, only partially active under normal temperature and fully active under heat) the application of the heat renders the alcohol fully active and causes it to soften or liquefy the said surface to a sufficient degree to establish a continuity or union between said celluloid and the adhesive, and the pressure causes the adhesive to penetrate and incorporate itself with the fiber of the surface of the wood. The. continued application of the heat dissipates the excess of alcohol and reduces the adhesive and the celluloid to a form in which they will solidify under ordinary temperature-that is to say, when the heat is withdrawn and the adhesive, the celluloid, and the wood are cooled. By the time it will solidify under ordinary temperaturethat is to say, when the heat is withdrawn and the adhesive, the celluloid, and the wood are cooled. The celluloid used for this purpose is necessarily in the form of thick sheets or boards resembling heavy pasteboard. The

adhesive can, therefore,do no more than soften the upper surface of the sheet, the middle of the sheetremaining unaffected by the solvent in the adhesive. This is illustrated in Fig. 3 of the drawings, the dotted portion above representing the celluloid, H, softened by the solvent in the adhesive, I, and the dotted portion below representing the celluloid softened by contact with the heated plate. The introduction of cold water into the plate A new cools the adhesive, the celluloid, and the wood, and entirely overcomes the softening action of the heat, the ordinary constituents of the celluloid being hardened and the small proportion of alcohol remaining being rendered latent or non-solvent. At the same time that the heat acts upon the adhesive it also softens or makes plastic the lower surface of the sheet of celluloid sufficiently to allow it to be compressed to greater density and to conform to the polished surface of the plate A. The softening action of the heated, polished surface does not extend uniformly through the entire thickness of the sheet. While the surface of the celluloid in contact with the heated plate becomes relatively-soft, the body of the sheet remains hard, or is but slightly softened. In no case can the entire sheet be suiliciently softened to cause the surface opposite the polished heated plate to adhere to the wood.

Experiment has demonstrated that with sheets of celluloid of the thickness used for key-boards one surface may be fused or liquefied by heat, while the opposite side is only slightly softened. Were the sheet thin like light paper it might be rendered soft through. out by the application of heat on one side; but in practice even the thin sheet could not be thus rendered soft enough to allow it to ad here to wood, for the reason that such a degree of softness can only be attained by subjecting the celluloid to a temperature but a little below its combustion-point. To deal with celluloid under such a temperature would be too dangerous to be practical.

In experimenting with small pieces it has been found that when the temperature necessary to thus soften the sheet has been attainedit is difficult to arrest the rise of temperature quickly enough to avoid the combustion that would result in an explosion were the celluloid confined. The cooling resulting from the introduction of cold water into the plate A, after the softening of the surface of the sheet of celluloid, causes such sheet, as well as the adhesive, to become thoroughly hardened and set, so that the board maybe at once removed from the press. The board is now found ready to be sawed into keys and shipped to customers. The celluloid is polished and hard and firmly secured to the wood, the celluloid and cement having been entirely relieved of their soft orgreen condition, and the wood has not been swollen from wetting, and the back mortises are not impaired, and there is no refuse from polishing to be removed. Furthermore, the polished surface of the celluloid is now found to be of a greater density (it having been compressed while softened by the heat) and of a higher polish than can be imparted to it by the old method. In the sheets of celluloid there frequently occur beneath the surface cells or cavities, which are cut and exposed by the old method of scrap ing and polishing, so that the sheets are made to be defective. These cavities or cells, if too small to be observed by the player of the instrument on which the keys are situated, are left on the key-board and sold in that condition; but if plainly visible the tops of the defective keys are removed and new strips of celluloid cemented in their places. The color of these new strips is not always of exactly the same shade as the balance of the set, which of course mars the beauty of the key-board. This necessary repairing is often more expensive than the iirst operation of mounting the whole sheet of celluloid. By my process such small cavities or cells are not out or exposed. On the contrary, as already set forth, the pressure of the polished plate compresses the celluloid and increases its density.

v Musicians have heretofore objected to celluloid key-boards because of their heavy, dead touch. I overcome this objection, because by my improved method the. celluloid key-boards, by reason of their greater density and higher polish, acquire the light, smooth touch of ivory boards.

By long study and experiment and the loss of large quantities of material I have found that most of the ordinary adhesives are not adapted to my process. I am convinced that the adhesive must furnish a liquid solvent of the celluloid as well as the quality of strongly incorporating itself with the fiber of the wood. The surface of the celluloid must be made soft, if only to the depth of the one-thousandth part of an inch; but such a solvent must be substantially latent under ordinary temperatures. An active solvent-such as ether, for exampie-will not serve my purpose, because the withdrawal of the heat and the application of the cold will not destroy the solvent action of the ether and harden and set the celluloid. On the contrary, the celluloid will be soft and green when taken from the press,in which condition it will not harden without a long period of seasoning attended by shrinking and warping. Therefore the claims hereto appended do not embrace ether and similar active solvents as equivalents of alcohol.

By my processI can produce a union between the celluloid and the wood stronger than the cohesion between the fibers of the wood itself, so that in removing the sheet the wood will be torn.

\Vhile I think it is preferable to use steam for heating the plate A, I do not wish to confine myself strictly to the use of steam, as said plate might be heated with agas-l'lame or otherwise.

I claim as my invention- 1. As an improvement in the art of applying sheets of celluloid to wood, the hereindescribed process, consisting of applying to one side ol'the celluloid an adhesive containing alcohol or some equivalent latent solvent of celluloid, then placing said side in contact with the wood, then placing the whole under pressure, then subjecting it while under pressure to heat, and then restoring it to normal temperature,substantially as shown and described.

2. As an improvement in the art of applying sheets of celluloid to wood, the hereindescribed process, consisting of applying to one side of the sheet of celluloid an adhesive containing alcohol or some equivalent latent solvent oicellnloid, then placing said side of the celluloid against the wood, then placing the whole under pressure, then subjecting it to heat while under pressure, and then artificially cooling the whole under pressure, whereby the solvent action due to the heat is at once destroyed and the celluloidand adhesive are immediately hardened and set, substantially as shown and described.

3. As an improvement in the art of applying sheets of celluloid to wood, the herein-described process, consisting of applying to one side of the celluloid an adhesive containing alcohol or some equivalent latent solvent of celluloid, then laying said side of the celluloid against the wood, then placing the whole under pressure with the outer surface of the celluloid in contact with a polished metal surface, then heating said polished surface su'l'iiciently to render the adjacent surface of the