US541997A

US541997A - feaveqa

Info

Publication number: US541997A
Authority: US
Publication date: 1895-07-02
Anticipated expiration: 1912-07-02

Description

(No Model) 0. J. FRAVEGA & A. JANET.

4 Sheets-Sheet 1.

FLEXIBLE SHAFT FOR DRIVING MECHANISM.

FIQJ

Patented July 2, 1895.

in ventorx 1m Model.) 4-Sheets--Sheet 2 0. J. PRAVEGA & A. JANET. PLBXIBLBSHAFT FOR DRIVING MECHANISM.

No. 541,997. Patented July 2, 1895,.

FIGJS FlG.5

(No Mo'deL') I 4 Sheets-Sheet 3.

G. J. FRAVBGA 8: A. JANET. FLEXIBLE SHAFT FOR DRIVING MECHANISM.

No.541,997. PatentdJuly 2,1895.

(No Model.) 4 Sheets -Sheet. 4.

C. J. FRAVEG'A'8Z; JANET. FLEXIBLE SHAFT FOR DRIVING MECHANISM.

No. 541,997. Patented July 2, 1895.,

FIG-.13

UNITED STATES PATENT OFFICE.

CHARLES J. FRAVEGA AND ARMAND JANET, OF TOULON, FRANCE.

FLEXIBLE SHAFT FOR DRIVING MECHANISMS.

SPECIFICATION forming part of Letters Patent No. 541,997, dated July 2, 1895. Application filed July 28, 1894:. Serial ll'o. 5l8,793| (N0 model.) Patented in France March 20, 1894, No. 237,076-

To all whom it may concern:

Be it known that we, CHARLES J ULES FRA- VEGA and ARMAND J ANET, citizens of France, and residents of Toulon, in the Department of the Var, France, have invented a new and useful Improvement in Flexible Shafts for Driving Mechanisms, (which has been patented in France by Patent No. 237,075, dated March 20, 1894,) of which the following is a specification.

This invention relates to flexible shafts serving for the transmission of rotary motion produced by an engine (stationed permanently or temporarily at a predetermined place) to mechanism, whatever its situation or direction of motion.

The flexible shafts hitherto used have consisted of suitably arranged metal spirals, while the main part of the improved flexible shaft constituting the present invention is a chain the operation of which as a flexible shaft is based upon the principle that if a twisting or rotary movement be imparted to one end of a chain the other end will tend to follow the direction of this movement, and the chain may consequently be utilized as a means of transmission of rotary motion provided it be prevented from forming loops or knots by winding about itself. This end is attained, according to the present invention, by either employing a suitably-fitted chain or by adding to an ordinary chain various parts or attachments, such as are hereinafter described, so as to make it fit for'use as a flexible shaft.

In the former case the flexible drivingshaft constructed according to this invention is characterized by the following peculiarity: The successive links of the chain may be of a shape which may vary according to circumstances, but which should be such that, when these consecutive links are fixed or jointed together, their hinge-pins are arranged alternately at right angles to each other. The shape of the links is such that they present abutting or contact surfaces to each other, which surfaces meet at predetermined times, so as to limit the amplitude of the angle between adjacent links. By such means the flexible shaft or chain can assume the general outline of a double curve without becoming looped or wound about itself, though the radius of the curve should at no point thereof exceed the minimum compatible with the proper operation of the driving-shaft in prac tice.

The invention will be best understood by reference to the accompanying drawings, in which- Figures 1 to t represent one form of flexible driving shaft or chain constructed according to our invention and having cylindrical links, the figures being respectively elevations at right angles to each other and two perspective views, also at right angles to each other. Figs. 5 to 8 are similar views representing a modified form of the link shown in the preceding figures. This form of link shall be herein referred to as a prismatic link. Fig. 9 isa front view of a length of chain consisting of four links constructed according to this invention, the two extreme ones of which have reached their limit of inclination or their extreme angular position in relation to the two central links, which form between them an intermediate angle; Fig. 10 is a top view of the same segment. Figs. 11 to 14 are respectively longitudinal elevations at right angles to each other and two perspective views, also at right angles to each other, showing a simplified form of link more especially intended for shafts which have no considerable strains to transmit.

Like reference numbers and letters designate like parts in all figures.

The link shown in Figs. 1 to 4; may be taken .to be formed from a section or length of a bar supposed to have been originally of circular shape in section, but cut or hammered down so as to present in two planes at right angles to each other a tongue forming the male part of the hinge 2 and perforated at one end as at 3, while at the other end of the link there is the corresponding groove or female part of the hinge formed by two checks 4 4:, having perforations 5 5, coinciding in such a manner that one of them forms a continuation of the other.

The male portion of one of the links engages in the female portion of the next link and the joint is completed by a hinge pin or bolt riveted or otherwise secured at its two ends or retained in place by other suitable means, so that when the chain is fitted toinc ' an ordinary flexible shaft.

gether its consecutive links can turn about their axes, such as a: a: and y y, alternately at right angles to each other.

As shown in the drawings, the tongue 2 and each of the cheeks 4 4 terminate in plane inclines 7 8 and 7 9, symmetrical in relation to the two diametrically-opposite planes of the link. When the angle of inclination, either at one or the other side of any one link in relation to the next link attains certain predetermined proportions, the

respective edges

8 and 9 of the tongue of the male part 2 and those of the checks 4 4 of the female part of the hinge meet, respectively, the bottom 10 of the groove between the two cheeks and the two plane surfaces 11 and 12, contiguous to the tongue 2. hen this position is reached, the angle of inclination cannot be further increased, and the consecutive links are thus prevented from forming too large an angle between them, as an unduly enlarged angle would interfere with the'proper operation of the flexible shaft in practice and be detrimental to the useful effect of the transmission. The chains or flexible shafts of this description, owing to the cylindrical shape of the links, may be advantageously surrounded with a tubular case or sheath made of a suitable fabric or flexible or elastic material, such as india-rubber, for example, capable of protecting them from dust and of deadening any shocks which they may sustain, while imparting to the whole the outward appearance of hen it is preferred to dispense with this casing, the chain may consist of prismatic links, such as are shown in Figs. 5 to 10. These links are constructed and arranged to operate in the same manner as the links hereinbefore described; but instead of being formed from a cylindrical bar or rod they may be formed from a prismatic bar of square or rectangular shape in section. A chain thus formed of links connected together by bolts 6 6 will present theappearance shown in Figs. 9 and 10, which figures clearly illustrate the manner in which in this form of chain the angle of inclination of one link to the other is limited.

It will be seen that in both the forms of links above described the bolts 6 only serve to prevent the links from becoming disconnected from each other, without, however, subjecting them to any strain in consequence of the twist imparted to the chain,inasmuch as each of the tongues or male parts of the hinge is snugly fitted between the twocheeks constituting the female portion of the hinge, which sustain any strain that may be produced by twisting the chain. This is an important advantage, insuring great durability to the chain, for while the mutual pressure exercised by the respective contact-surfaces of adjacent links is distributed over a comparatively large surface the bolts, on the other hand, are subjected to a very slight strain, and the wear both of these bolts and of the links themselves is reduced to a minimum. These facts are sufficiently important to outweigh any consideration of cost in those cases where the object in view is to procure a durable device and to transmit considerable power. Vhere, however, the flexible shaft is intended to transmit but small power, it may be sufficient to employ a chain formed of links constructed in the manner illustrated in Figs. 11 to 14, the arrangement being in that case considerably simplified. These links, like those shown in Figs. 5 to 10, have a prismatic body, but include no female portion. They are joined together by means of bolts or pins traversing the projections 2, the thickness of each of which is equal to one-half of the body of a link, the angle of inclination of every two consecutive links being limited in the same manner as in the preceding forms of links.

It will be readily seen that the construction of these links is extremely simple and cheap; but the bolts 6 in this case have to resist the strain resulting from the tendency of the contact-surfaces of the links to move away from each other, and they are also more subject to wear. Where it is desired to surround this chain with a protecting case, these links, like those shown in Figs. 1 to 4, may be constructed with a cylindrical body fitting the shape of the case more exactly. To avoid complication, this last type of cylindrical link has not been shown in the drawings, but it will be readily understood from the description of the last form of link.

We wish it to he distinctly understood that we do not limit ourselves to the few forms here represented only to facilitate the perusal of the description of our invention, and that modifications can be made, according to circumstances, in the shapes, dimensions, proportions, and material employed in the construction of the improved flexible drivingshaft so long as the substance of our new invention or im provement is employed.

We claim ICO IIO

' A flexible power-transmitting shaft composed of links hinged together with the hinge axes at different angles and said links provided with abutting or contact surfaces within the angles of flexure of said shaft, whereby the shaft has the degrees of flexure limited at the several hinges by the chain itself unre-- strained by outside means such as non-rotating casings, substantially as described.

In testimony whereof we have signed this specification in the presence of two subscribing witnesses.

C. J. FRAVEGA.