US2150981A - Timpano adjuster - Google Patents

Description

March 21., 1939. I w. F. LUDWIG TIMPANO DJ'USTER 2 Sheets-Sheet l Filed March 3l, 1957 7 1//1'0/22 FZIQMI March 21, 1939. w. F, LUDWIG TIMPNO ADJUSTER Filed March 5l, 1937 2 SheetS-Sheet 2 Patented Mar. 21, 1939 UNITED STATES TINI'PANO ADJUSTER William F'. Ludwig, Oak Park, Ill.

Application March 31,

6 Claims.

This invention relates to improvements in mechanism for varying the tension of the heads of drums, commonly known as a timpano adjuster, and more particularly the heads of kettle drums, and has for its object to provide very simple, relatively cheap and very eflicient means' for accomplishing the objects of the invention with ease and dispatch by the drummer.

The main object of the present invention is to provide a timpano adjuster which will maintain itself in any position to which` it may be adjusted without resort to a separately operable means for locking the same in such position.

Another object of the invention is to provide a 1 5 timpano adjuster which is very simple, durable and light, is easily and quickly operable and which is, as to its main portion, housed within the shell or casing oi the drum.

Suitable embodiments of the invention are illustrated in the accompanying drawings, where- Fig. 1 is a central, vertical, sectional View of a kettle drum equipped with a timpano adjusting means constructed in accordance with the invention, the same being sho-wn mainly in elevation with certain parts broken away.

Fig. 2 is a detail, fragmentary, central longitudinal View on an enlarged scale, showing the middle portion of the mechanism of Fig. 1.

Fig. 3 is a vertical, fragmentary, detail, sectional view taken on the line 3 3 of Fig. 2.

Fig. 4 is a fragmentary, vertical detail sectional view on an enlarged scale, showing a part of the mechanism of Fig. 1.

Fig. 5 is a detail, sectional View taken on the line 5 5 of Fig. 4.

Fig. 6 is a view similar to Fig. 2 showing another form of embodiment of the invention.

Fig. is a detail, vertical sectional view taken on the line '1 -'I of Fig. 6.

The mechanism of the present invention comprises a substantially conventional type of hoop l equipped at regular intervals with brackets 2, and with which the kperipheral edge of the drum head 3 is suitably connected and which is disposed substantially telescopically over the upper cylindrical portion 5 of the casing 5 of the drum. The mechanism also includes the substantially conventional type of bell crank lever t which is pivotally secured by means ci a pivot pin 'l with a bracket 8 mounted upon the drum casing below the hoop I. Each of the several levers t is equipped at its elbow with a rotatable member t having a threaded opening in which the lower end of the tension screw Il! is engaged, the shank of said 1937, Serial No. 133,963

screw being rotatably mounted in a sleeve II constituting a part of each bracket 2 carried by the hoop I Each screw Ill] is equipped with a collar I2 by means of which it is held against downward movement relatively to the sleeve II.

The drum is equipped with said bell crank levers 5, and the above described parts connected therewith at regular intervals throughout its periphery in such number as the manufacturer may deem necessary to the production of the desired results.

The kettle drums are usually mounted upon suitable bases or supports, which, in the instance illustrated, are diagrammatically shown at I3, said supports being disposed about the vertical axis of the casing 5.

In the present construction, the casing 5 is equipped at its lowest point with a suitable casting lli having a threaded opening disposed coaxially with the drum` casing and in which the lower threaded end of a vertical tension rod I5 is engaged, the latter being suitably held against rotation by means of a lock-nut I6 of conventional function.

In the instance illustrated the rod I5 is shown A to be tubular for weight reduction. purposes only, and there is mounted upon` the same a sleeve I1 which is vertically movable thereon and which is equipped at its upper end with a pair of outwardly projecting anges I8 through which pivot pins i9 pass for pivotally connecting with said flanges IB the pairs of levers 20, which act similarly to toggle levers and are, therefore, hereinafter referred to as toggle levers.

Each pair of said toggle levers 2B is equipped at its upper end with a pair of antifriction rollers 2| which bear against the head 22 rigidly mounted upon the upper end of the rod or tube I5 as by means of threaded connection between said rod and said head. In the instance illustrated the head 22 is equipped with a lower surface 23 which is disposed perpendcularly of the axis of the shaft l5.

A pair of opposed and respectively right and left threaded nuts or sleeves 24 and 25 equipped with side trunnions 25, are mounted between` the upper ends of the toggle: levers 29 and have their trunnionsl extended toy constitute stud-shafts upon which the antifriction rollers 2l are mounted.

A right and left threaded shaft 2l is journaled between its ends in a bearing in the head 22 and is vengaged at its opposite .end portions with the said nuts or sleeves 24 and 25 so that, upon rotation yof said shaft 2l, said sleeves 24 and 25 will be moved in respectively opposite directions simultaneously. The said shaft 2l is suitably connected at one end with the operating shaft 28 which, at its outer end, is connected in a suitable manner with the inner end of the shaft 29 of a hand wheel 30, said shaft 29 being mounted in a bearing 3| carried by the drum casing. The ends of the shaft 28 are preferably somewhat loosely secured to they shafts 29 and 2l, respectively, as by means of pins disposed transversely of each other in a well-known manner to provide a universal joint connection which permits the bearing 3l to be disposed out of exact axial alignment with the shaft 2l.

A second shaft 32, similar to shaft 2U, con- `nects the other end of the shaft 2i' with a stud shaft 33 journalled in a bearing mounted on the drum casing substantially diametrically opposite to the bearing 3l, the connections of the shaft 32 with the shafts 'il and 33 being also effected in the manner of a universal joint connection of any suitable type. The shaft 32 may be omitted without affecting the mechanism, but is utilized in the instance illustrated merely as a reinforcing element.

Tension rods 35 which are pivotally connected with the lower ends of the longer arms of the bell crank levers 6, are secured at their inner ends to the lower end portion of the sleeve Ill. The latter is provided with an annular flange lll which is provided with vertical recesses 3l disposed in radial alignment with the respective bell crank levers 6 and correspond in number with the latter, the ends of the said tension rods 35 being suitably engaged with the said flange and the walls of the said recesses 3? thereof.

In Fig. 1 the sleeve l'l is shown as disposed at the lower limit of its movement and in this position the drum head 3 is under its maximum tension. By rotating the hand wheel 35i in the di rection determined by the threads of the sleeves 24 and 25, the latter will be moved away from each other and the tension of the drum head il will thus then cause the hoop I to move upwardly to relieve its tension to the degree determined by the least movement of said sleeves and 2li, it being obvious, of course, that the rod 35 will at all times be maintained under some degree of tension by the action of the drum head 3. The adjusting screws I 0 determine the minimum tension to which the drum head is to be subjected when the sleeve I1 is disposed at the upper limit of its movement.

The hand wheel 3U may be disposed within easy reach of the drummer, who generally is required to play a number of drums of dilferent types, and enables him to tune the kettle drum easily and quickly to suit requirements.

Owing to the fact that the tension on the rods 35 tends always to move theisleeve li upwardly, it causes the rod I5 to be maintained under ten sion at all times and this permits a very light rod to be used in the structure. All parts of the mechanism may be made comparatively light in weight as none of them is subjected to any appreciable stress and for this reason the bell crank levers B are made, preferably, or U -shaped stampings, the web or middle portion of which is opposed to the casing 5 of the drum.

In the structure of Figs. 6 and 7, the rod l is equipped with the head 38 which consists of a rectangular member the lower portion of which is suitably rigidly secured to the upper end of' the rod I5. Pairs of toggle levers d@ and 42 are pivotally secured at their upper ends to opposite sides of the upper portion of said head 38 and are pivotally secured at their lower ends to the sleeve I'I. At their points of connection with each other the toggle levers 39 and 42 are pivotally secured to the trunnions of the right and left threaded sleeves 40 and 4I which correspond to the sleeves 24 and 25 of the structure of Figs. 1 5 inclusive.

The right and left threaded shaft 2l is engaged with both the sleeves 4E! and 4I and is ope-rated by means of the shaft 43 having universal joint connections with the shaft 2l and with the shaft B of the hand wheel 3!! as in the case of the structure of Fig. 1.

In the structure of Figs. 6 and '7, the universal joint connections between the shaft 43 and the shafts 2l and 29 are required because of the fact that the sleeves 40 and 4I will move vertically, responsively to the rotation of the shaft 2l by the operation of the toggle levers 39 and ft2 to a greater extent than is true of the levers 2@ of Figs. 1-5 inclusive.

One of the essential features of the present structure resides in the fact that the rod I5 is at all times subjected only to tensile stresses and further in that the mechanism can be manufactured cheaply because of the wide range of tolerances which it permits of without affecting its efficiency. The simplicity of the mechanism and its ease of operation are very advantageous over timpano adjuster-s now in use as far as the latter are known to me.

I claim as my invention:

l. In a drum including a casing having a central axis and a drum head disposed perpendicularly to said axis, the combination with substantially conventional drum-head tensioning devices including bell crank levers and adjusting devices engaged with the said bell crank levers and the drum-head hoop, of a tension rod disposed substantially axially of the drum casing and secured to the latter at a point opposed to the said drumhead, a sleeve sldable longitudinally on said rod, tension rods connecting said sleeve with said bell crank levers ior actuating the latter to increase tension on said head as said sleeve moves in one direction, a device rigid with said rod, toggle links pivotally engaged with said device and said sleeve for actuating the latter, and a manually operable member disposed exteriorly of the drum casing and operatively connected with Said toggle links for actuating the latter to effect movement of said sleeve.

2. In a drum including a casing having a central axis and a drinn head disposed perpendiculariy to said axis, the combination with substantially conventional drum-head tensioning devices including bell crank levers and adjusting devices engaged with the latter and the drum-head hoop, of a tension rod disposed substantially axially of the drum casing and secured to the latter at a point opposed to the said drum-head, a sleeve slidable longitudinally on said rod, tension rods connecting said sleeve with said bell crank levers for actuating the latter to increase tension on said head as said sleeve moves in one direction, a device rigid with said rod, a manually rotatable member extending substantially transversely ol said rod7 and means operatively engaged with said device, said sleeve and said rotatable member lor actuating said sleeve as said last-named membei is rotated.

3. In a drum including a casing having a central axis and a drum head disposed perpendicularly to said axis, the combination with substantially conventional drum head tensioning devices including bell crank levers and adjusting devices engaged with the latter and the drum head hoop, of a tension rod disposed substantially axially oi the drum casing and secured to the latter at a point opposed to the said drum head, a sleeve slidable longitudinally of said rod, tension rods connecting said sleeve with said bell crank levers for actuating latter to increase tension on said head as said sleeve moves in one direction, a head rigid with said rod, a manually rotatable right and left threaded shaft journalled in a bear ing in said head and extending substantially transversely of said rod, threaded sleeves having threaded engagement with said shaft for movement by the latter longitudinally thereof and substantially transversely of said rod as said shaft is rotated, and toggle links connecting said threaded sleeves with said rstnianied sleeve for imparting movement to the latter as said threaded means are actuated by rotation of said shaft.

4. In a drum including a casing having a cenl tral axis and a drum head disposed perpendicularly to said axis, the combination with substantially conventional drum head tensioning devices including bell crank levers and adjusting devices engaged with the latter and the drum head hoop, of a tension rod disposed substantially axially of the drum casing and secured to the latter at a point opposed to the said drum head, a sleeve slidable longitudinally of said rod, tension rods connecting said sleeve with said bell crank levers for actuating the latter to increase tension on said head as said sleeve moves in one direction, a bearing rigid with said rod, a manually rotatable right and left threaded shaft journalled in said bearing and extending substantially transversely of said rod, threaded sleeves mounted on said shaft for movement by the latter longitudinally thereof and substantially transversely of said rod, and toggle levers connecting said threaded sleeves with said rst-named sleeve for transmitting movement from said threaded sleeves to said rst-named sleeve.

5. In a drum including a casing having a central axis and a drum head disposed perpendicularly to said axis, the combination with substantially conventional drum head tensioning devices including bell crank levers and adjusting devices engaged with the latter and the drum head hoop, of a tension rod disposed substantially axially of the drum casing and secured to the bottom of the latter at a point opposed to the center of said drum head, a sleeve slidable longitudinally on said rod, tension rods connecting said sleeve with said bell crank levers for actuating the latter to increase tension on said head as said sleeve moves in one direction, a bearing rigid with the upper end of said rod, a threaded manually rotatable journalled in said bearing, a threaded sleeve having threaded engagement with said threaded shaft, and a toggle lever connecting said firstnamed sleeve with said threaded sleeve for actuating said iirst-named sleeve as Said shaft is rotated.

6. lin a drum including a casing having a central axis and a drum head disposed perpendicularly to said axis, the combination With conventional drurn head tensioning mechanism, including bell crank levers and adjusting devices engaged with the latter and the drum head hoop, of a rod disposed centrally of the drum casing and extending transversely of the drum head and rigidly secured to the bottom of the drum casing, a sleeve slidable on said rod, tension rods connecting said sleeve with said bell crank levers for actuating the latter to adjust the tension of the drum head as said sleeve is moved from one position to another, a bearing rigidly mounted upon the upper end of said rod below the drum head, a right and left threaded shaft journalled between its ends in said bearing, threaded sleeves disposed upon opposite sides of said bearing mounted upon said shaft, toggle levers connecting said threaded sleeves with said first-named sleeve, a hand wheel equipped with a hub journalled in a bearing in the drum casing disposed substantially in axial alignment with said rstnamed bearing, and a rod connecting said hub of said hand wheel with said right and left threaded shaft, rotation of the latter causing said threaded sleeves to move in respectively opposite directions thereby to vary the position of the nrst-named sleeve to cause said tension rods to actuate said bell crank levers and vary the tension on the drum head.

WILLIAM F. LUDWIG.

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