US 3459093 A
Description (OCR text may contain errors)
Aug. 5, 1969 TOMEHICHI NISHIURA ETA!- 3,459,093
' DRUMHEAD Filed Oct. 24, 1966 M 2 Sheets-Sheet 1 FIG. I
5, 1959 TOMEHICHI NISHIGURA ETAL 3,459,093
nmmnsw 2 Sheets-Sheet 2 Filed Oct. 24, 1966 FIG. 5
United States Patent 3,459,093 DRUMHEAD Tomehichi Nishiura and Niyoshi Muray'ama, Tokyo, Japan, assignors, by mesne assignments, to Nippon Gakki Co., Ltd., Shizuoka, Japan Filed Oct. 24, 1966, Ser. No. 588,806 Claims priority, application Japan, Nov. 1, 1965, 40/88,496 Int. Cl. G011] 13/02 US. 01. 84-411 4 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a drumhead, and, more particularly, it relates to an improvement in the means for securing a sheet and a sheet clamping frame constituting the drumhead.
A drumhead is consisted of a circular sheet stretched across an annular clamping frame, said sheet being made of animal skin or synthetic resin. The sheet of animal skin, which has been commonly used heretofore, is secured to the frame by wetting the sheet with water to soften the same and then wrapping and adhering the peripheral edge of the sheet around the annular frame of wooden material. Recently the sheet of synthetic resin has become widely used, but it can be hardly secured by such softening and adhering process as in the sheet of animal skin. In order to secure the sheet of synthetic resin to the annular frame, two forms of structure have been employed. One of these forms comprises an annular metal frame having U-shaped cross section, in the channel of which the peripheral edge of the sheet is inserted and secured by resinous bonding material which fills up said channel as disclosed in R. D. Belli et al. US. Patent No. 2,934,- 989. In this form, the portion of the edge of the sheet embedded in the bonding material may be provided with apertures to enhance the securement of the edge in the bonding material. The other form comprises an annular frame consisting of a core member and a surrounding member, and the peripheral edge of the sheet is wrapped around said core member and pressed by the surrounding member whereby the peripheral edge is tightly gripped between these members, as disclosed in W. F. Ludwig US. Patent No. 2,979,981.
It is an object of the present invention to provide a drumhead in which a sheet made of animal skin or synthetic resin is effectively and tightly secured to an annular frame.
It i another object of the invention to provide a drumhead of the above kind which is simple in construction and can be easily manufactured.
In accordance with the present invention, there is provided a drumhead which comprises a vibratile sheet, a sheet receiving ring and a sheet retaining ring, both rings having generally U-shaped cross-sections and being assembled in a confronting relationship with each other so that only one leg of one of the U-shaped rings may be securely retained between two legs of the other U-shaped ring, the vibratile sheet being bent in a corrugated fashion and firmly gripped between the engaged rings of the thus assembled rings at its peripheral edge, and the re- 3,459,093 Patented Aug. 5:, 1969 taining ring being adapted to be pressed downward by a counter hoop when the drumhead assembly is mounted on a drum body.
The present invention will be more fully understood from the following detailed description with reference to the accompanying drawings which illustrate some preferred embodiments of the present invention, in which:
FIG. 1 is a plan view of a drumhead according to the present invention;
FIG. 2 is a vertical section of the drumhead shown in FIG. 1;
FIG. 3 is an exploded sectional view of the drumhead shown in FIG. 2; and
FIGS. 4, 5, 6 and 7 are fragmentary sectional views showing modified forms of the drumhead according to the present invention.
Referring to FIGS. 1-3, the drumhead according to the present invention comprises a sheet clamping frame including heet receiving and retaining rings A and B, both having U-shaped iross section, which are arranged and fitted in confronting relationship with each other, and a vibratile diaphragm sheet 1 having its peripheral edge bent in corrugated fashion and held between said rings A and B. The vibratile diaphragm sheet 1 may be made of either animal skin or synthetic resin, which is formed at its peripheral portion with a downwardly bent section 1, a folded-back section 1" and a further folded-back section 1", which sections are preferably preformed by heating and pressure-moulding. The sheet receiving ring A may be made by stamping or machining to form a channel a. The sheet retaining ring B has an inverted U-shape in cross section having an outside wall slightly longer than an inside wall. The lower end of the outside wall is preferably bent inward along the lower outside surface of the ring A to tightly grip the same.
Thus, according to the invention, the sheet receiving and retaining rings A and B having U-shaped cross section are fitted with each other and the peripheral edge of the sheet 1 is bent and tightly held between these rings. That is, the U-shaped portion including the downwardly bent section 1' and the folded-back section 1" of the sheet 1 is fitted in the channel a of the ring A, and the inverted U-shaped portion including the folded-back section 1" and the further folded section 1" is fitted on the outside wall of the ring A, while said inverted U-shaped portion including the sections 1" and 1" is fitted in the channel b of the ring B, which is fixed to the ring A by bending the lower edge of the ring B along the lower outside surface of the right A, whereby the sheet is firmly gripped at the peripheral edge to the sheet clamping frame. The ring B is adapted to be pressed downward by a counter hoop at the top surface when the drumhead is mounted on a drum body, the ring B being further pressed into the ring A so as to more firmly grip the peripheral edge of the sheet 1.
FIGS. 4 and 5 show other embodiments of the present invention, FIG. 4 showing a sheet retaining ring B .having L-shaped cross section and FIG. 5 showing a sheet retaining ring B having a wedge-like cross setcion. In either case, the sheet 1 is bent at its peripheral edge along the inside surface of the channel of the ring A. When the drum head is mounted on the drum body 2 as shown in FIGS. 4 and 5, the ring B is pressed downward at the top by the counter hoop 3, as in the first embodiment shown in FIGS. 1-3.
The sheet receiving and retaining rings may be made of light metal, such as aluminum, or synthetic resin, such as glass-fiber-reinforced plastics. The vibratile sheet may be made of animal skin or synthetic resin, such as polyester film or polycarbonate film. Preferably the sheet is preformed so as to be corrugated at the peripheral edge. It is preferable to apply adhesive of synthetic resin or synthetic rubber material which has flowing property before curing onto the contacting surfaces of theSheetand/Or by the action of the adhesive after drying andcuring;
Moreover, the adhesive serves to directly connect both rings together where the sheet is not present therebetween.
The one or both rings may be formed at their engag: ingsurfaces with one or more grooves 4 which servesto store the adhesive and helps to flow the adhesive, as shownin FIG. 6. Also, one or both rings may be formed at their engaging surfaces with serrations 5 in order to promote the adhering efiect of the adhesive as shown in FIG. 7. The sheet 1 is bent at its peripheral edgealong the inside surface of the channel of the ring A. When the drum head is mounted on the drum body 2 as shown in FIG. 6, the ring B is pressed downward at the top surface by the counter hoop 3.
Although the foregoing embodiments have been described in detail, there are obviously many other embodiments and variations which may be made by those skilled in the art without departing from the spirit or scope of the present invention.
What is claimed is:
1. A drum head comprising a vibratile sheet, a sheet receiving ring and a sheet retaining ring, both said rings having generally U-shaped cross-sections and being assembled in a confronting relationship with each other so securelyrta'ined'between two legs of'th'e other U-shaped ring, said vibratile sheet being bent in a corrugated fashion and firmly gripped between the engaged rings of the thus assembled rings at itsperipheral edge, and said retaining ring being adapted to be pressed downward by a counter hoop when the drum head assembly is mounted on a drum bodyv, i
2. A drum head according toclaim 1, wherein adhesive material is-a'pplied on the surface of the peripheral edge portion'of the vibratile sheet and the engaging surfaces of the rings.
3. A drum headaccording to cIaim'I, wherein at least one of said rings is formed at their engaging surfaces with one or more grooves.
4. A drum head according to claim 1, wherein at least one of said rings is formed at their engaging surfaces with serrations.
References Cited UNITED STATES PATENTS 2,326,305 8/1943 Morarre 84-411 2,934,989 5/1960 Belli et a1 84-411 2,979,981 4/1961 Ludwig 84-411 RICHARD B. WILKINSON, Primary Examiner J. F. GONZALES, Assistant Examiner.