US1615228A - Tensioning device - Google Patents

Description

Jan. 25,1927;

F. J. MARTHY' TENSIONING DEYICE Filed March 25 1925 jig. l.

INVENTOR Francis K]. Martha %wfl% ATTORNEYS Patented Jan. 25, 1927.

UNITED sir-Ares FRANCIS J. MARTHY, or HAZIJETON, PENNSYLVANIA.

'TENSIONING DEVICE.

Application fled March 25, 1925. Serial No. 18,205.

This invention relates to tensioning devices ada-pted to be employed in combination with timing pinsfor piano strings.

The tuning pin of an instrument is ordinarily mounted within an opening provided in the wrest plank or pin block but such opening becomes enlarged due to the to tation of the pin during tuning and also due to strains caused by the tension of the string so that it is diflicult to hold the pin against rotation after a predeterminet l {number of tunings. Because of such detectin the pin blocki-t is necessary to set the pins but such setting seldom if ever can be effected after any length of time because of the-defective wrest planks and becauseot the twisting of the pins.

Anobject of the invention is the provision of adevice adapted to be employed in connection'with tuning pins whereby the strings ofthe instrument'may be easily, accurately andfinely'adjusted and securely-held in their adjusted positions.

A. further object ot thc invention is the provision of a device adapted to be employed in connection withtuniug pins for {pianos'and in which the pin is held against movement after its adjustment and upon which is mounted a removable sleeve to which the string *is secured for finely adjusting the *tension of the strings which will maintain the tension.

This invention will be best understood from a consideration of the following detailed description, in view I of the accompanying drawings forming a part of the specification; nevertheless it is to be understood that the invention is not confined to the disclosure, being susceptible of such changesand modificationswhich sha l-l define no material departure from the salient features of the invention as expressed in the appended claims.

In the drawings:

Figure 1 is a fragmentary view in elevation showin my invention applied to the metal plate of the piano.

Figure 2 is a transverse vertical section taken through one of the pins.

Figure 3 is a View in perspective of the preterred form of my invention showing the parts in detached relation.

Figure Lisa view in perspective ota modified form of the invention.

Figure 5 is a view showing the modified form of the invention shown in Fig. 4 as applied to the usual makes of the pianos now in use.

Figure 6 is a "view in perspective ot'the sleeve'a-ssociated with the pins shown in Figures 4t and 5.

- Referring more particularly to the drawings, 10 designates a metal plate 01 a piano whichis provided with a plurality of sleeves 11 integrally formedw-i tl'i the plate. llaoh of the sleeves is provided with 'a passage 12 1n which is mounted a timing pin 13. This pin has one end threaded as shown at 14 adapted to receive a nut 15 which engages a washer 16 abutting a shoulder 40 on the pin 13 so that the washer is slightly spaced from the free end of the sleeve. The pin 13 has a toothed wheel or flange 17 rigidly attached thereto and adapted to engage the outer face of the metal plate 10 and cooperate with the nut l5to prevent displacementot said pin.

A spring pressed pawl 18 secured to the metal plate 10 is adapted to engage the teeth of the flange 17 and lock the pinagainst rotation.

The pin at 19 is provided with a spiral screw or thread w lric h is of the multiple trapezoidal or square thread with considerable pitc'h. I

Mounted on the threaded portion if) is a sleeve 20 having a collar '21 in which is formed a recess or countersunk portion 22 adapted to receive a hub 23 on a 'nut 24; which engages the threads 25 on the pin 19. The sleeve '20 is provided with threads 26 adapted to engage the threads on the portion 19 of the pin. The pin at its outer extreme end is square in cross section as shown at 27 which is adapted to be engaged by any suitable tool. The nut 24 has a hexagonal conformation likewise adapted to be engaged by a suitable tool for'turning the same. The collar 21 is provided with a perforation 28 in which is adapted to be inserted the end of a piano string 29.

In Figure 4 is shown a modified form of the invention and in which the portion 19 is devoid of threads but provided with a pin 30 which projects laterally from diametrically oppositc points and which projects through curved slots 31 in a sleeve 32. The sleeve 32 has a collar provided with a perforation 34: adapted to receive a piano wire 29. The collar 33 is located inter- Lil mediate the ends of the sleeve 32. The pin 13 in this case is also provided with a threaded end i l, a threaded portion :25 adapted to be engaged by a nut tor adjusting and locking the sleeve 32 against movement. The end of the pin is square in cross section adapted to be engaged by any suitable tool. The toothed annular flange ii is also employed and is adapted to be engaged by the pawls 18 with the inner end of the sleeve 32 abutting the member 17.

In Figure 5 is shown the modilied 'l'orm secured to the metal plate of the piano whereby the usual terms of metal plates may be adapted with the present invention. in such a case an enlarged opening 35 is provided in the plate lit through which is inserted a metal sleeve 11. This sleeve is provided with a flange 36 upon which is pivotally mounted a spring pressed pawl 3. adapted to engage the teeth of a" annular flange 17 formed integrally with the pin 13. The sleeve 11 is externally threaded and a nut 38 engaging the threads on the sleeve is adapted to lock the sleeve to the metal plate in conjunction with the annular flange 36. The pin 13 has a threaded 'end 1st upon which is screwed a nut 15 for forcing the washer 16 in rigid engagement with the shoulder %0 on the inner end of the pin 10. The washer 16 and wheel or flange 17 cooperate to prevent displacement of the pin.

The operation of my device is as follows:

Either construction as shown in Figure or 5 may be employed and the pins 13 or 13 are locked in place as has been explained by means of the toothed annular flange 1'? and the nut 15 and washer 16 with the nut located at one end of the sleeve 11 or 11 and the toothed flange 1'7 in engagement with one face of the metal plate 10 or 10 The pin 13 or 13 is rotated in the usual manner until substantially the pitch of the string is had whence the nut 2% is turned until the proper tension is placed upon the string to produce the exact tone desired. The nut 24: trictionally engaging the end of the sleeve 20 or the sleeve 32 causes the sleeve to be turned and since the string is secured to the sleeve the string will be further tcnsioned. As the nut 24: is revolved in the construction shown in Figure 3 the sleeve is also rotated to its engagement with the threads on the portion 15) ot' the pin while in Figure 4t the sleeve is revolved and maintained in its adjusted position through the pins moving through the arcuately shaped slots 31 of the sleeve 32.

Having described the invention, this is claimed:

1. A tensioning device for piano strings comprising a tuning pin, a sleeve mounted on the pin for independent rotation, means for operatively connecting the sleeve with the pin so that the sleeve may be revolved with the pin, and a nut threaded on the pin to trietionally contact with the sleeve for causing rotation of the sleeve independently of the pin when the nut is rotated, and means included in the pin, nut and sleeve for causing a dill'erential speed of rotation between the nut and the sleeve.

2. A tensioning device for piano strings comprising a tunin pin, a sleeve mounted on the pin tor independent rotation, means for operatively connecting the sleeve with the pin so that the sleeve may be revolved with the pin, and a nut threaded on the pin to trictionally contact with the sleeve for causing rotation of the sleeve independently of the pin when the nut rotated, means for locking the pin against rotation in one direction, and means included in the pin, nut and sleeve for causing a differential speed of rotation between the nut and the sleeve.

3. A tensioning device for piano strings comprising a tuning pin, a sleeve mounted on the pin for independent rotation, means for operatively connecting the sleeve with the pin so that the sleeve may be revolved with the pin, and a nut threaded on the pin to trictionally contact with the sleeve for causing rotation of the sleeve independently out the pin when the nut is rotated, said sleeve being provided with means for securing the piano string to the same whereby the end of the piano string will be coiled on the sleeve during tensioning of the string, the operative means which connects the sleeve with the pin being constructed to cause a differential speed of rotation between the nut and the sleeve.

t. A tensioning device for piano strings comprising a metal plate provided with a plurality of hollow sleeves projecting rearwardly from said plate, a tuning pin mounted in each sleeve, the tuning pin being provided with a ratchet wheel forming a shoulder to engage one face of the metal plate, means cooperating with the wheel to prevent displacement of the pin from a sleeve, pawls to engage the ratchet wheel for preventing rotation of the pin in one direction, a sleeve rotatably mounted on the pin, and cooperating means on the pin and the sleeve for causing the sleeve to be moved longitudinally of the pin and permitting independent rotation of the sleeve on said pin, a nut threaded on the pin adapted to trictionally contact with the sleeve so that when the nut is rotated the sleeve will be revolved independently of the pin, and means for securing a piano string to the sleeve.

5. A tensioning device for piano strings comprising a metal plate provided with a plurality of hollow sleeves projecting rearwardly from said plate, a tuning pin mounted in each sleeve, the tuning pin being provided with a ratchet wheel forming a shoulder to engage one face of the metal plate, means cooperating with the wheel to prevent displacement of the pin from a sleeve, pawls to engage the ratchet Wheel for preventing rotation of the pin in one direction, a sleeve rotatably mounted on the pin, cooperating threads on the pin and on the sleeve for causing the sleeve to be moved longitudinally of the pin and permitting independent rotation of the sleeve on said pin, a nut threaded on the pin to frictionally contact with the sleeve so that when the nut is rotated the sleeve will be revolved independently of the pin, and means for securing a piano string to the sleeve.

6. A tensioning device for piano strings comprising a metal plate provided with a plurality of hollow sleeves projecting rearwardly from said plate, a tuning pin mounted in each sleeve, the tuning pin being provided with a ratchet wheel forming a shoulder to engage one face of the metal plate, an end of the pin being threaded and. a nut screwed onto the threaded end of the pin for cooperating with the ratchet Wheel to prevent displacement of the pin from the sleeve, pawls to engage the ratchet wheel for preventing rotation of the pin in one direction, a sleeve rotatably mounted on the pin, and cooperating means on the pin and the sleeve for causing the sleeve to be moved longitudinally of the pin and permitting independent rotation of the sleeve on said pin, a nut threaded on the pin adapted to fric tionally contact with the sleeve so that when the nut is rotated the sleeve will be revolved independently of the pin, and means for securing a piano string to the sleeve.

In testimony whereof I afiix my signature.

DR. FRANCIS J. MARTHY.

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