US 1678709 A
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July 31,1928. 1,678,709 W. SCHURMANN SECTIONAL 0R LINK SHAFT Filed July 27, 1926 2 Sheets-Sheet 1 a E .1 8 J 5 5 8 5- l July 31, 1928; 1,678,709
. W. SCHURMANN SECTIONAL R LINK SHAFT Filed July 27, 1926 2 Sheets-Sheet 2 Patented July 31, 1928.
WALTER SCI-I'URMANN, OF DUSSE LDORF, GERMANY.
SEGTIONAL OR LINK HAFT.
Application filed July 27, 1926, Serial No.
This invention has reference to sectional or link-shafts, and it is intended among other objects and advantages to provide shafts of the kind referred to 'bymeans of which a greater degree of rigidity and accuracy may be obtained than'it was possible to arrive at in link-shafts as heretofore constructed. "T he link shafts or sectional shafts heretofore known, as far as I am aware are open to the objection that they possess only a compara-v tively small degree of movability, and that there is so much play and idle motion in the direction of rotation in the joints as to pre elude smooth running without the occurrence of erking and striking movements; and there is, moreover, the inconvenience that with a change of the direction of rotation the shafts will extend or will be reduced in length.
Now, this invention, to be described herewith is adapted to overcome these inconveniencies, and among other advantages it is particularly,distinguished by the fact that it posseses a great degree of flexibility, while making provision to avoid all possibilities of idle motion in the direction of movement. In accordance with this invention the joints are constructed substantially on the principle of the universal joints or Cardan-joints and in such a manner that the individual links, when revolved, will be moved without play or dead motion.
The invention will be more fully described by reference to the accompanying drawing, showing by way of exemplification one of the possible embodiments of the principle of this invention. In the drawing :Figures 1 and 2 represent the sectional or linkshafts in two different elevational views. Figure 3 is a cross section on the line 3-3 of Figure 2. Figures 4 to 7 illustrate the assembling of the sections of the shaft. A somewhat modified construction is shown in. two different views in Figures 8 and 9, and Figures 10 to 12 illustrate the manner of assembling the sections.
As will appear from the drawing (Figures 1 to 7) the individual links, 1, 2, 3, 4 and so on may be made from punched out flat pieces of material and each link is provided at its ends with substantially semi-circular recesses or openings 5, and the fork-shaped ends are composed of inwardly curved or hawk- 125,227, and in Germany October 1, 1925.
shaped jaws 6 having acutely beveled, outwardly diverging inner faces at their free ends. In the openings 5 separate circular discs 8 with crosswise arranged peripheral slots 7 are inserted, and upon these discs the succeeding links are mounted which are disposed at right angle with relation to the next preceding link. In this manner the sections of the shaft are assembled, so
as to produce a link-shaft with Cardan like or universal joints. The recesses 7 of the discs 8 correspond exactly to the thickness of the material of the particular links, and by this meansidle movement in the joints during the revolution of thelinks is avoided. The distance of the fork-like ends 6 of the links from each other governs the movability of the shaft, and, as shown for instance in Figures 1 and 2 of the drawing, the link 2 may be moved in a vertical plane through the angle with relation to the link 3, and
simultaneously through the angle B in the.
horizontal plane. The said angles comprise each degrees, thereby resulting in a very high degree of movability of the shaft.
Figures 4-7 illustrate the assembling of the shaft. In the recess 5 of the link 1 a disc 8 is mounted by first inserting-the disc in the transverse direction according to Figure 5, and then turning it around through 90 degrees, whereupon va second member 2 is pushed onto the disc 8, as shown in Figure 7. This causes the ends 6 of the link or member 2 to be somewhat spring actuatingly spread apart, which is made possible by the slot 9. After the parts have been assembled, unintentional detaching of the same is no longer possible in view of the fact that in the assembled position the links are only adapted to turn relatively to each other through the angles a and [3 (Figures 1 and 2 The novel sectional or link-shaft according to this invention may be employed with or without a guide tube. WVhen a guide tubing is used the shaft is very satisfactorily circularly guided within the guiding tube, and inasmuch as the shaft makes contact with the tubing at the narrow joints only, only very slight friction is produced. The operating point of the torque is situated in a very favorable manner at the periphery of the shaft. As a further important advanthe thickness and width of the fork-shaped leg 13 of themembflri 10. WVhen assembling.
the parts the cross piece 14 is first positioned as inthe form of construction first mentioned (Figure 5'), whereupon the second'member isintroduced from above, the-recess12 allowing of the insertion of. the leg 13 (Figure 11). Thereupon the second member .10 may be turned into the operative position. according to Figure 1 2. The assembling of the parts is therefore 'efi'ecte'd without. any spring-acting straining of.. the fork shaped leg13."
While the invention has been described herein with reference to what are considered two preferred forms of embodiment, it
should beunderstoodthat itis not limited thereto, but it may find expression in other embodiments and modifications, without thereby deviating from the scope and spirit of the invention, as particularly pointed out in the claimshereunto appended.
I clain' z 1. Aflexible shaft or coupling comprising at least two flat linlr'plates having forked end portions and a nearly' circular opening between the arms of the forks, and a flat disk within the openings of the forked ends of the link plates and havin transverse notches in its periphery arrangedin working pairs; one pair of notches receiving the fork arms of one link plate and the other pair of notches receiving the fork arms of the other link plate.
2. A flexible shaft or coupling comprising. at least two flat link plateshaving fork end portions and a nearly circular opening be tween the arms of the forks, the outer and inner surfaces of the arms extending on arcs, and a flat circu lar disk within the openings of the forked ends of the linkplates and having. transverse notches. in its periphery arranged in working pairs; one pair of notches receiving the fork arms v of one. link plate and the other pair ofnotches.'receivinglthe. fork arms of. the other link. plate, the edges ofthe link plates being longitudinally. con
caved between its forkedfends', wherebyeach.
link plate is intermediately contractedi.
3-. A link shaft-comprising crossi-li-nkwise.
connected flat'llink members having. forked ends with circular recesses for. .the lreception of a connecting member,and a connecting meniber formed-of .a flat. disk with cross-wise arranged cut-outsi for the reception of the forked ends offthe links. I l H 4. A flexible shaft. or coupling comprising. a coupling disk having pairsv of peripheral. notches at right angles to each other, and flatl link plateshaving forked endsreceiving the disk and respectively 'engaging,ithe notches axial slot intersecting its forkedJend. and
: therein, one of said link plates having; an
rendering the jaws of said forked-end resilient for spring-apart and.: spring-reaction actions in engaging andmai'ntaining.engagement with the notches in the. disk engaged thereby, Y i 7 In testimony WhereofI 'aiiixmysignature.