Apparatus For Positioning Piano Hammers For Drilling

Abstract

A viselike clamp is adapted to grip the head of a piano hammer and is provided with supporting means so that the hammerhead may be arranged at any desired angle with respect to a stationary drill-supporting means so that the head may be drilled to provide an opening to receive the end of the stem which supports the piano hammer.

Description

BACKGROUND OF THE INVENTION

It is well known that piano hammers are supported by stems or shanks for movement into engagement with the strings, and the angles of the stems relative to the head vary throughout the length of the piano. It is therefore necessary to drill holes through the wooden hammerheads at various angles to receive the supporting stems. This is necessary in building the piano and occasionally, in use, the stems break and the end left in the hammer must be drilled out to receive the end of a new stem.

SUMMARY OF THE INVENTION

A viselike gripping device forms part of a support and includes a jaw movable with respect to a stationary jaw to grip a piano hammerhead for the drilling operation. The support is pivoted adjacent the clamp on a transverse horizontal axis so that the support and a hammer therein may be tilted at any angle desired according to the angle of the opening to be drilled in the hammerhead to receive the stem. A vertical support carries an arm provided with an opening through which the drill stem is adapted to project to drill the necessary opening. The support for the clamp is adapted to be moved longitudinally as well as tilted to assist in properly positioning it for the drilling operation, and means is provided for adjusting the vise transversely to further provide a high degree of accuracy in adjusting the hammerhead for the drilling operation. Means is also provided engageable against a clamped hammerhead to positively prevent it from rocking in the clamp during the drilling operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation of the apparatus;

FIG. 2 is a plan view of the same;

FIG. 3 is an end elevation looking from the right in FIGS. 1 and 2;

FIG. 4 is a vertical section on line 4-4 of FIG. 1;

FIG. 5 is a vertical longitudinal section on line 5-5 of FIG. 2;

FIG. 6 is a plan view of a magnetic device serving as a modified means for steadying and bracing a hammerhead to be drilled;

FIG. 7 is a section on line 7-7 of FIG. 6;

FIG. 8 is a plan view of a modified form of holding magnet; and

FIG. 9 is a section on line 9-9 of FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 to 5, inclusive, the numeral 10 designates the horizontal base of the device as a whole on the top of which is mounted a plate 12 coextensive therewith and provided adjacent one end with a vertical socket 14 welded or otherwise secured thereto and adapted to receive the lower end of a vertical supporting post 16 attached to the plate 12 by a screw or other fastening element 18. The post 16 may be positively fixed against rocking movement on its axis by a setscrew 18 threaded through the socket 14.

At a point spaced above the base 10, a collar 20 surrounds the post 16 and is provided with a vertical key 22, which may be separate from or integral with the collar 20, and is slidable in a vertical keyway 24 formed in the post 16. The collar 20 is fixed in adjusted vertical positions by a wingnut 26. The collar 20 carries a laterally extending arm 28 provided with a drill stem guide 30 arranged in an opening 32 in the free end of the arm 28. The guide 30 carries a flange 34 seating on the top of the arm 28, and the guide 30 is fixed to the arm 28 by a screw 36.

A movable plate 38 is slidable on the plate 12 and is guided for longitudinal movement therealong by a longitudinal key 40 (FIGS. 4 and 5) slidable in a keyway 42 formed in the plate 12.

A support indicated as a whole by the numeral 44 is arranged above the plate 38 and is provided with a transverse bolt 46 extending therethrough and provided at its ends with nuts 48 threaded thereon. This bold 46 extends through the vertical arms 50 of L-shaped brackets 52 to be further described below.

It will be apparent that the support 44 is pivoted on the transverse axis of the bolt 46. The support 44 carries a clamping device comprising a jaw 54, integral with the support 44, and a separate jaw 56 movable toward and away from the jaw 54. Each of these jaws is provided with a faceplate 58 secured in position by screws 60 and each is shouldered toward its upper end at its inner face as at 62 to support and clamp between the jaw members the hammer 64 of a piano. This hammer includes the usual wooden head and felt butt as will be apparent, and it is through the wooden head that openings are to be drilled at predetermined angles to receive the supporting stems for the heads. Each faceplate 58 has its bottom edge cut away as at 53 to provide depending leg portions 55 (FIG. 4), both of which terminate above the adjacent flat surface 57 of the body 44.

The support 44 is elongated horizontally, extending a substantial distance to the right (FIGS. 1 and 2) from the jaw members as at 65. At a point spaced longitudinally from the jaw member 56 the support is provided with a preferably integral boss 66 in which is threaded a rod 68 provided at its left-hand end in FIG. 5 with a reduced shank 70 having a round head 72, thus fixing the threaded rod 68 against axial movement relative to the clamping head 56. The outer end of the rod 68 is provided with a head 74 having a headed rod 76 slidable therethrough and adapted to provide leverage for rotating the threaded rod 68 to move the clamping head 56 toward and away from the clamping head 54.

The movable clamping head 56 is a part of a crosshead indicated as a whole by the numeral 78 (FIG. 5) having a depending relatively wide rib 80 operating between spaced sidewalls 82 of the support 44. These sidewalls are undercut as at 86 to form guideways. These guideways are engaged by a longitudinally extending plate 88 attached by screws 90 to the depending rib 80. Thus the clamping head 56 is guided for movement toward and away from the stationary head 54.

The support 44 is pivoted on the axis of the bolt 46, as previously stated, and is arranged above and in contact with a longitudinal plate 92 notched longitudinally as at 94 to provide space for the heads of the screws 90. The plate 92 rests upon the plate 38.

At opposite sides of the support 44 are arranged elongated triangular plates 96 pivoted by a screw 98 to the plate 92 and provided in a plane above such screw with a slot 100 in which are slidable screws 102 threaded in the respective sides of the elongated portion of the support 44. It will become apparent that the support 44 may have its right-hand end swung upwardly for counterclockwise turning movement about the bolt 46 upon the loosening of the screws 102, and when tilted to the proper position, these screws may be tightened to fix the body 44 in an adjusted position. The tilting of the support 44 predetermines the boring angle relative to the vertical as viewed in FIG. 1. The positioning of the head of the piano hammer longitudinally of the apparatus is determined by loosening the head 103 of a screw 104, having an operating bar 110, and slidable in a slot 105 in the plate 38. The movement longitudinally takes place through movement of the plate 38 which is provided for by the arrangement of the key 40 (FIG. 5) in the keyway 42. Along the edge of the plate 38 (FIG. 2) is arranged a scale 112 through which the degree of longitudinal movement of the plate 38 may be determined.

Such movement of the plate 38 preferably takes place through operation of a screw 114 threaded through a lug 116 (FIG. 2) carried by the plate 38. The screw 114 is journaled in a bearing 118 carried by the plate 12 and the screw is rotatable by turning a knurled head 118 carried thereby.

Means are provided for facilitating the accurate placing of successive piano hammers which are to be identically drilled. To this end, a post 122 is fixed at its lower end to the plate 38 and is provided at a point spaced above such plate with two collars 124 fixed to the post in adjusted positions by wingnuts 126. Each of these collars carries a slidable rod 128 fixed to the associated collar by a wingnut 130. When a piano hammer is in the clamping device, the wingnuts 126 will be loosened so that the rods 128 can be swung around in a position to be slid into engagement with the piano hammer, whereupon the wingnuts 130 will be tightened.

The angle brackets 50 are also mounted to be moved transversely of the plate 38 to adjust the position of the piano key in the same direction relative to the drill bit mounted in the guide 30. Each bracket 50 is provided with a lower horizontal portion 132 seating upon a plate 134 fixed by screws 136 to the plate 38. The plate 134 is provided with a slot 138 through which extends a screw 140 carrying a bottom head 142 slidable in a groove 144 formed in the plate 134. The screw 140 is threaded in an upper head 146 having a transversely slidable leverage rod or handle 148 to facilitate the tightening of the head 146, acting as a nut for the screw 140. When it is desired to adjust the clamping devices transversely of the apparatus, the heads 146 will be turned to loosen them with respect to the screws 140, whereupon the brackets 50 will be moved transversely of the apparatus to the desired extent, followed by the tightening of the heads 146 by the rods 148. Only one bracket 50 and associated elements are necessary when working on small objects such as piano hammers, but both such assemblies may be helpful in working on larger heavier objects.

Magnetic devices for the same purpose as the rod 128 may be employed, and two forms of such device are shown in FIGS. 6 and 7, and 8 and 9. Referring to FIG. 6, the numeral 150 indicates a horseshoe magnet carrying a central stem 152. This stem may be engaged against the piano hammer and the magnet 150 may be magnetically engaged with any suitable portion of the apparatus to hold it in position so that the stem 152 will engage the piano hammer.

In FIGS. 8 and 9 a U-shaped type of magnet 154 is shown, the ends of which may directly engage the piano hammer while the magnet is a whole will be engaged with a metallic portion of the structure to hold it in position. This type of magnet may be provided with a central opening 156 for the positioning therein of a stem similar to the stem 152 and for the same purpose.

OPERATION

The head of a piano hammer to be drilled is arranged between the clamping jaws 54 and 56, resting on the shoulders 62. The clamping device is closed by rotating the rod 76 to move the clamping jaw 56 into tight engagement with the hammer. Depending upon the angle at which an opening is to be drilled, the device is adjusted with respect to the drill guide 30. The drill projects through such guide, which is always vertical, and the clamping device and associated elements are adjusted relative to the drill. These openings are drilled vertically, or downwardly at an angle toward the left in FIG. 1. Assuming that the drilling is to be done angularly, the screw 102 will be loosened and the body 44 swung upwardly at its right-hand end so that the hammerhead assumes the proper angle to the vertical as viewed in FIG. 1. During this drilling operation, the screw 102 slides relatively toward the right in FIG. 1, and when the proper angle is reached, the screw 102 is tightened. When properly so adjusted, the theoretical axis of the opening to be drilled will lie in the plane of the axis of the drill transversely of the apparatus. The theoretical axis may not be in such plane when the tilting operation referred to takes place. Under such conditions, the knurled head 118 will be rotated to move the plate 38 to the left or right in FIGS. 1 and 5 to bring the vertical plane of the theoretical axis of the opening to be drilled in the corresponding plane of the axis of the drill bit. If lateral adjustment is necessary, the rods 148 (FIGS. 1 and 2) will be moved to turn the heads 146 on the screws 140 to relieve pressure of the heads 146 on the horizontal legs 132 of the angle brackets 50. The entire clamping structure then may be moved laterally of the apparatus, whereupon the hammerhead will be properly positioned for the drilling operation. The heads 146 will then be tightened.

The rod 128 will now be brought into operation. The screws 126 will now be loosened to permit the collars 124 to turn on the vertical post 122. The screws 130 will then be loosened to free the rods 128 for sliding movement. These rods are then moved into engagement with the portion of the hammer projecting to the right of the clamping device as viewed in FIG. 3, whereupon the screws 126 and 130 are tightened. The drill bit is then moved downwardly to drill the necessary opening in the head of the hammer. Upon completion of the drilling operation, the rods 128 will be left in position in engagement with the head of the hammer, if one or more hammers are to be identically drilled, whereupon the movable jaw 56 will be disengaged from the hammerhead and the latter removed. Instead of using the rod 128, one of the forms of the magnet shown in FIGS. 6 to 9, inclusive, may be used to engage the hammer for the same purpose.

Where the angle of the drilling so requires, the jaw plates 58 may be moved, it being desirable that the straight section of the hammerhead rest squarely on the shoulders 62. Under such conditions, one of the screws 60 of each faceplate 58 may be removed and the other setscrew loosened, whereupon the end of each plate 58 from which the screw has been removed will drop to its limit of movement, thus inclining the shoulders 62 of the plates 58.

Any desired type of drilling mechanism may be employed, such as a hand drill. Guides 30 of different diameters may be employed, and a guide may be replaced with one of a different size merely by removing the screw 36, lifting the guide from position and replacing it with another guide.

The drill-supporting arm 28 is fixed against rotation by engagement of the key 22 in the keyway 24. However, the collar 20 obviously may be vertically adjusted, as desired, by loosening the wingnut 26, moving the collar vertically to the desired position, and then tightening the wingnut 26.

It will be apparent that the present apparatus provides means for supporting and accurately positioning a hammerhead to drill an opening at any desired angle for the reception of the stem to which it is to be connected. The angles of the openings drilled will vary throughout the length of a piano, and the present apparatus will properly position a hammerhead for the necessary drilling at any angle.

While the apparatus has been described specifically for the purpose of drilling the heads of piano hammers, it will be apparent that it is capable of general application to any type of element which may be clamped as described for the drilling of openings at desired angles.

From the foregoing it will now be seen that there is herein provided an improved apparatus for positioning piano hammers for drilling which accomplishes all of the objects of this invention and others, including many advantages of great practical utility and commercial importance.

As various embodiments may be made of this inventive concept, and as many modifications may be made in the embodiments hereinbefore shown and described, it is to be understood that all matter herein is to be interpreted merely as illustrative, and not in a limiting sense.

Claims

I claim:

1. Apparatus for use in drilling articles such as piano hammers, comprising a normally stationary vertical drill guide, means for clamping the article to be drilled beneath said guide, means for supporting said clamping means for adjusting the pitch of the article in order to drill an angular opening in the article, and second means mounted against said clamping means for supporting the bottom of the article and for adjusting the roll of the article in order to drill an angular opening in the article which is not parallel with any of the three dimensional planes of the article.

2. Apparatus according to claim 1 wherein said clamping means comprises a pair of jaws relatively movable toward and away from each other and said second means includes a fastener and a faceplate secured by said fastener against the inner face of each said jaw, each faceplate having a horizontal ledge formed by a reduced top portion to support the article to be drilled while the pitch of the article is adjusted by appropriate rotation of each said faceplate on each said jaw about the axis of each said fastener.

3. Apparatus according to claim 2 including horizontally slidable means, a vertical shaft, a plurality of collars vertically slidable and rotatable about the longitudinal axis of said shaft, and rods slidable mounted within said collars transverse with said vertical shaft, said vertical shaft and said means for supporting said clamping means secured to the top of said slidable means allowing said rods to make physical contact with the surface of the article at a plurality of locations to facilitate the positioning of the roll and pitch of another article to be identically drilled regardless of any sliding of said clamping means relative to said drill guide.