US3191293A - Method of making a plano plate - Google Patents

Description

June 29, 1965 H. s. WICKHAM 3, 91,293 METHOD OF MAKING A PIANO PLATE Filed Feb. 23, 1960 BYEPTYJLOMW HTTOE/Vf) United States Patent Piano Plate Company, Springfield, Ohio, a corporation of Ohio Filed Feb. 23, 1960, Ser. No. 10,224 3 Claims. (Cl. 29-529) This invention relates to a piano plate and more particularly to improvements in the upper base bridge section thereof.

The conventional piano plate includes a series of 40 guide pins fixed in its upper base bridge section in positions uniformly inclined at a angle to a vertical to the plate. These guide pins are essential for proper positioning and tensioning of piano strings which pass over the upper base bridge section. The strings extend from tuning pins at one marginal portion to one end of a piano plate generally at right angles to the upper base bridge section adjacent thereto where they respectively nest at the junction thereof with one of the guide pins therein, in the acute angle provided by its inclination. From the guide pins the strings are sharply angled to hitch pins at an opposite marginal portion of the plate, offset toward the opposite end thereof. This provides a containment of the strings at the upper base bridge section which prevents them from displacement by riding up and over the pins as they are tensioned to tune a piano. It also maintains the strings in contact with the upper base bridge section. This enables optimum tuning of a piano to be effected and maintained.

The conventional procedure for applying the noted guide pins is relatively slow and quite inefiicient. Holes must be drilled in the upper base bridge section to accommodate the pins at a critical angle. Then the pins must be carefully positioned in the holes by hand to insure that they are fixed at the required angle and with the proper degree of projection from the bridge section. If there is any inaccuracy in the holes or the pins it will be readily seen that it may be difficult to maintain the strings in a fixed position under established tension. This will create tuning problems.

The present invention is directed to a simplification of piano plates and their method of fabrication which obviates the need for the above mentioned guide pins and thereby reduces their cost. It provides a piano plate having an improved upper base bridge section which facilitates effective and efiicient positioning of strings which are passed thereover.

The object of the invention is to simplify and improve piano plates whereby they may be more simply and economically fabricated and more eiiicient and satisfactory in use.

A further object of the invention is to provide a simplified procedure for fabricating piano plates whereby to provide improvements in their bridge section.

An additional object of the invention is to provide improvement in the upper bridge section of piano plates.

Another object of the invention is to provide improvements in piano plates and their method of fabrication so as to obviate the need for an involved application of guide pins to the bridge sections thereof.

A further object of the invention is to provide a piano plate possessing the advantageous structural features, the inherent meritorious characteristics and the mode of operation herein mentioned.

With the above and other incidental objects in view as will more fully appear in the specification, the invention intended to be protected by Letters Patent consists of the features of construction, the parts and combinations thereof, and the mode of operation as hereinafter de scribed or illustrated in the accompanying drawings, or their equivalents.

3,191,293 Patented June 29, 1965 Referring to the accompanying drawing wherein is shown one but obviously not necessarily the only form of embodiment of the invention,

FIG. 1 is a plan view of a piano plate embodying the features of the invention;

FIG. 2 is an enlarged fragmentary cross sectional view of the plate of FIG. 1 taken on line 22 thereof showing a portion of its upper base bridge section in elevation; and

FIG. 3 is a cross sectional view taken on line 3-3 of FIG. 2.

Like parts are indicated by similar characters of reference throughout the several views.

While the invention is particularly described herein with reference to the upper bass bridge section of a piano plate it should be kept in mind that it can be advantageously employed with reference to other bridge sections.

A piano plate embodying the present invention has an upper base bridge section 2 formed integral therewith. The section 2 is in the form of a narrow elongated bead 3 projecting from the upper surface of the plate 1 adjacent a marginal portion 7. The head 3 includes a vertical rib-like projection 4- at its apex which is coextensive therewith. The projection 4 is provided with notches 5, having parallel sides, spaced longitudinally thereof and uniformly inclined at a 15 angle to a vertical to the plate 1. The notches 5 extend inwardly to the head 3 the full depth of the projection 4.

The plate 1 is provided with tuning pins 6 conventionally positioned to one end thereof on its marginal portion 7 adjacent the upper base bridge section 2. A series of corresponding hitch pins 8 are also conventionally positioned on the plate 1 at its marginal portion 9 opposite the portion 7 and offset relative the tuning pins to which they relate in a conventional manner.

As shown in the drawings with reference to the upper base bridge section 2, piano strings 10 respectively extend from the tuning pins 6 substantially at right angles to the head 3 and through the inclined notches 5 aligned therewith which are provided in the rib-like projection 4. From this point the strings are then sharply angled to the appropriate hitch pins 8. As the strings are conventionally tensioned for tuning purposes, it will be obvious that they will seat firmly to the bead 3 within the projection 4 integral therewith. The upper base bridge section 2 as provided herein insures a simple accurate stringing of piano strings It with reference thereto and inherently provides positive positioning of the strings in contact with the bead 3 so as to enable optimum tuning conditions for the strings. Employing the invention features will thus facilitate establishing and maintaining the required tension on piano strings which pass over the bridge section of the piano plate in which they are incorporated.

The illustrated embodiment of the invention can be simply fabricated. The piano plate 1 is initially cast to form the head 3 and the rib-like projection 4 integral therewith in a manner and to a degree clearly obvious from FIG. 3 of the drawings. A fixture is then employed which rotatably mounts a series of cutting blades oriented to lie in spaced parallel planes uniformly inclined at a 15 angle to a vertical. The cutting blades so mounted are connected to conventional controls for simultaneous and joint rotation thereof. The plate 1 and the fixture mounting the cutting blades are so positioned that on relative advancement thereof the rotating cutting blades will simultaneously engage the projection 4 on the bead 3 to simultaneously cut the parallel sided notches 5 therein. Thus, the piano plate 1 is provided with an upper base bridge section 2 of an improved nature in which critically oriented notches are simply and efiiciently effected.

The invention thus provides a piano plate 1 which obviates the need for conventional guide pins in its upper base bridge section as well as the involved procedure employed for applying such pins which has been followed for many, many years in the prior art. The improved upper base bridge section provided is of a nature to facilitate the stringing of the piano plate and as noted previously enables optimum tuning conditions to result in the piano in which it is employed. Also, a piano plate in accordance with the invention affords guide means at its upper base bridge section having increased strength and stability and offering a better containment and posi tioning of the strings thereon. Of course other bridge sections can be similarly formed and improved.

It should be noted that only such detail of a piano plate and the fabrication thereof has been disclosed herein as is pertinent to illustration of the present invention.

From the above description it will be apparent that there is thus provided a device of the character described possessing the particular features of advantage before enumerated as desirable, but Which obviously is susceptible of modification in its form, proportions, detail construction and arrangement of parts without departing from the principle involved or sacrificing any of its advantages.

While in order to comply With the statute the invention has been described in language more or less specific as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein disclosed comprise but one of several modes of putting the invention into efiect, and the invention is therefore claimed in any of its forms or modifications within the legitimate and valid scope of the appended claims.

Having thus described my invention, I claim:

1'. A method of forming a bridge section on a piano plate, including the steps of forming integrally with the plate a raised head of longitudinal extent solid in crosssection and convexly curved in a transverse sense, there being an integral rib extending longitudinally of the bead at the top thereof, and cutting a longitudinal series of transverse string receiving slots in said rib to a depth reaching to the convex surface of said bead, said slots a being cut with parallel sides inclined to the axis of said bead, the bottoms of said slots extending to and providing for the bearing of a received string directly on said bead.

2. A method of forming a bridge section on a piano plate having first and second longitudinally spaced apart laterally oifset marginal portions mounting tuning pins and including the steps of forming integrally with the plate a raised bead in parallel adjacent relation to said first marginal portion, said bead being solid in crosssection and having an integral relatively raised rib running centrally thereof along its top, and cutting a longitudinal series of transverse string receiving slots in said rib to a depth reaching to the upper surface of said bead, said slots being cut with their sides inclining in a direction opposite to the direction in which the said second marginal portion is offset laterally of the first said marginal portion.

3. A method according to claim 2, characterized in that said slots in said rib are cut to be aligned with respective tuning pins, strings extending from said tuning pins to said hitch pins passing through said slots and being held by the said inclined formations of said slots in the lower parts thereof.

References Cited by the Examiner UNITED STATES PATENTS 403,743 5/89 Durick 84-209 466,346 1/92 Hastings 84-209 677,465 7/01 Norcross.

867,002 9/07 Betz.

878,926 2/08 Ziegler 84-188 1,736,495 11/29 Grad 29-529 1,867,788 7/32 Weber 84-188 2,476,151 7/49 Le Jeune 29-529 2,838,834 6/58 Ganine 29-529 FOREIGN PATENTS 297,047 3/ 17 Germany.

9,373 5/93 Great Britain.

247,356 2/26 Great Britain.

607,518 9/48 Great Britain.

WHITMORE A. WILTZ, Primary Examiner.

CARL W. ROBINSON, HYLAND BIZOT, Examiners.

Claims (1)

1. A METHOD OF FORMING A BRIDGE SECTION ON A PIANO PLATE, INCLUDING THE STEPS OF FORMING INTEGRALLY WITH THE PLATE A RAISED BEAD OF LONGITUDINAL EXTENT SOLID IN CROSSSECTION AND CONVEXELY CURVED IN A TRANSVERSE SENSE, THERE BEING AN INTEGRAL RIB EXTENDING LONGITUDINALLY OF THE BEAD AT THE TOP THEREOF, AND CUTTING A LONGITUDINAL SERIES OF TRAVERSE STRING RECEIVING SLOTS IN SAID RIB TO A DEPTH REACHING TO THE CONVEX SURFACE OF SAID BEAD, SAID SLOTS BEING CUT WITH PARALLEL SIDES INCLINED TO THE AXIS OF SAID BEAD, THE BOTTOMS OF SAID SLOTS EXTENDING TO AND PROVIDING FOR THE BEARING OF A RECEIVED STRING DIRECTLY ON SAID BEAD.

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