US656735A

US656735A - Bicycle-frame.

Info

Publication number: US656735A
Application number: US1981800A
Authority: US
Inventors: Frank A Wilmot
Original assignee: Wilmot & Hobbs Manufacturing Co
Current assignee: Wilmot & Hobbs Manufacturing Co
Priority date: 1900-06-11
Filing date: 1900-06-11
Publication date: 1900-08-28
Anticipated expiration: 1917-08-28

Description

Nd. 656,735. Patentd A 28, I900. F. A. WILMUT.

BICYCLE-FRAME.

(Application filed June 11, 1900.)

(No lolodal.)

WITNESSES INVENTOR STATES v PATENT OFFICE.

FRANK A. WILMOT, OF BRIDGEPORT, CONNECTICUT, ASSIGNORTO THE WILMOT & nouns MANUFACTURING COMPANY, or SAME PLACE.

BICYCLE-FRAME.

SPECIFICATION forming part of Letters Iatent No. 656,735, dated August 28, 1900.

Application filed June 11, 1900. Serial No. 19,818. 0 model-3 To all whom it may concern:

Be it known that I, FRANK A.WILMO'I,a oiti zen of the United States, residing'at Bridgeport, county of Fairfield, State of Connecticut, have invented a new and useful Bicycle- Frame, of which the following is a specification.

My invention relates to the manufacture of bicycle-frames, and has for its object to provide a bicycle-frame having ample strength to meet all of the ordinary requirements and most of the extraordinary requirements of use and which shall be perceptibly lighter than any frame now in use which approximates a safe degree of strength. In other words, my invention embodies a safe and practical maximum of strength and minimum of weight.

It is of course well understood that the two weakest points in the construction of both diamond frames and drop frames are the seat-post tube at or near the crank-hanger and the lower tube at or near the head, for the reason that the throw of the cranks tends to strain the seat-post tube at the crankhanger and the movements of the front wheel in use tend to strain the lower tube at the head, strains at both points frequently re sulting in breakdowns and serious accidents. I have discovered as a result of careful and extended experiments that by increasing the diameter of the lower end of the seat-post tube relatively to the upper end thereof and of the upper end of the lower tube relatively to the lower endthereof without appreciable variation in the thickness of the metal at any portion of the tubes I am enabled to produce a very much stronger frame with a given weight of metal or a frame having a required degree of strength that shall be very much lighter than any bicycle-frame now known to the trade.

My invention is applicable to all classes of seamless and sheet-metal tubing-as, for example, the well-known clincher tubing, covered by patents granted to me March 16, 1897, Nos. 578,799, 578,800, and 578,801.

In the accompanying drawings,forn1in gpart of this specification, Figure 1 is an elevation of a diamond bicycle-frame, so called, showing the application thereto of my novel invention; Fig. 2, an elevation of a drop bicy ole-frame, so called, illustrating the application thereto of my novel invention; Fig. 3, a section on the line 3 3 in Figs. 1 and 2 and Fig. 4. is a section on the line at lin Figs. 1 and 2.

l0 denotes the upper tube of either a diamond or drop frame; 11, the upper rear fork; 12, the lower rear fork; 13, the head; 14, the front fork; 15, the lower tube, and 16 the seat= post tube.

The gist of my invention lies in making the seat-post tube smallest at its upper end and largest at its lower end, with an intermediate taper and of practicallyuniform thickness throughout, and in making the lower tube smallest at its lower end and largest at its upper end, with an intermediate taper and of practically-uniform thickness throughout. In practice these tubes may be made straight at the ends to receive the usual attaching-lugs, (not shown in the drawings,) which project from the parts to which the tubes are attached, and so much of the upper end of the seat-post tube as receives the seat-post may be made of uniform internal diameter, so as to provide for the use of an internal expander as a means of looking a seat-post. The size of the upper and lower rear forks and the upper tube and the matter of whether said parts are of uni form diameter or tapered is not of the essence of my invention.

In Fig. l I have illustrated a diamond frame having an upper tube of uniform diameter and in Fig. 2 I have illustrated a drop frame having an upper tube made smallest at its lower end and largest at its upper end and tapering uniformly from one end to the other in order to harmonize with the lower tube.

Having thus described my invention, I claim- 1. A bicycle-frame including a seat-post tube as a member thereof, said tube being formed with its smallest diameter at the upper end and the greatest diameter at the lower end and an intermediate taper, the metal thereof being of practically-uniform thickness throughout, substantially as described. 1

2. A bicycle-frame including a lower tube as a member thereof, said tube being formed with its smallest diameter at the lower end and greatest diameter at the upper end and an intermediate taper, the metal thereof being of practically-uniform thickness throughout, substantially as described.

3. A bicycle-frame having a lower tube with its smallest diameter at the lower end and greatest diameter at the upper end and a taper between said points and a seat-post tube with its smallest diameter at the upper end and its greatest diameter at the lower I in presence of two witnesses.

FRANK A. WILMOT.

Witnesses:

A. M. WOOSTER, S. W. ATHERTON.