US1892339A

US1892339A - Conical spiral spring

Info

Publication number: US1892339A
Application number: US297209A
Authority: US
Inventors: Gross Siegfried
Original assignee: Krupp Stahl AG
Current assignee: Krupp Stahl AG; Fried Krupp AG
Priority date: 1927-08-29
Filing date: 1928-08-03
Publication date: 1932-12-27
Anticipated expiration: 1949-12-27
Also published as: GB296343A; BE353362A; FR658731A

Description

Dec.27,1932. SGROSS 1,892,339

CONICAL SPIRAL SPRING Filed Aug. 3, 1928 F lg. 4;

W w W w \/A w -Q T al Patented Dec. 27, 1932 PATENT E'FICE SIEGFRIED GRGSS, OF ESSEN, GERMANY, ASSIGNOR T FRIED KRUPP AKTIENGESELL- SCHAFT, OF ESSEN-ON-THE-RUHR, GERMANY CONICAL SPIR'AL SFP-,ING

Application filed August 3, 1928, Serial No.

The invention relates to conical spiral Springs and consists primarilj,7 in winding the spring with such a pitch, that all of the spring threads come at least approximately simultaneously to abut on one abutment of the spring, when the ultimate load is attained.

In order that the invention may be more easily understood, an embodiment of the new conical spiral spring is illustrated in the drawing which accompanies and forms part of this specification. In this drawing Figure 1 is an aXial section through the spring, while Figures 2 and 3 are elevation and top v ew, respectively, of the steel band intended for t ie manufacture of the spring.

According to the invention the spring is wound with such a pitch, that the distance of each point, e. g. the point P, of the narrow surface al turned toward the spring` abutment B, of the steel band A forming the spring in unloaded condition, from this abutment as, e. g. a is equal to the distance this point has to travel under the action of the ultimate load of the spring. This design results in the fact, that in contradistinction to the well-known conical spiral Springs, in which the individual coils come successively to abut on the one spring abutment upon the spring being compresscd, all of the spring coils simultaneously abut on the abutment upon the ultimate load being attained, so that all of the coils take part in accumulating the deformation work during the whole stroke of the spring. Besides, a linea-r relation exists in the present conical spiral spring between the load of the spring and its stroke, which relation is in many cases dcsired and does not actually exist with the hitherto known conical spiral Springs. Fig. 2 illustrates this relationshlp, whereln the spring 1s shown' 1n developed form. Not untll the maximum load is exerted u Jon the s orinO` does the orb tion m coincide with a llne NN', representing one of the spring abutments. In the case when but half of the ultimate load is exerted upon the spring, the displacement of the lower edge of the spring corresponds to the line PQ, wherein the point Q, is equidistant 297,209, and in Germany August 29, 1927.

from line NN' and m. The displacement of the other portions of the spring is relatively similar, being one half of that caused when the ultimate load is exerted. lVhen the latter is eXerted, the lower edge of the spring abuts substantially simultaneously upon the spring abutment to which corresponds the line N PN'.

For the manufacture of the described spring steel bands may be used which are either of substantially uniform width and varying thickness or of varying width and uniform thickness or, finally, of both varying width and varying thickness. Preferably the spring is manufactured from a steel band that possesses a substantially uniform width and a thickness varving in such a. nianner, that the coils of the spring, except its unelastic end portions, increase in thickness from the inmost coil to inclusively the outmost one. Of all conical spiral springs of the same power a spring of this construction occupies the smallest space.

'Vhat claim and desire to secure by Letters Patent, is

1. A conical spiral spring having a graduated cross section decreasing from its base to its tip with said graduated cross section so related to the pitch with which said spring is wound that the coils thereof abut on one spring abutment at least approximately simultaneously, upon the ultimate load being exerted.

2. A conical spiral spring having a graduat-ed cross section decreasing from its base to its tip with said graduated cross section so related to the pitch with which said spring is wound that the coils thereof abuton one spring abutment at least approximately simultaneously, upon the ultimate load being exerted, the pitch being such that each of said coils of said spring in loaded condition is displaced an equal fraction of the distance of said coils from the one spring abutment in the rest position, said fraction being the ratio of the load applied to effect said displacement to the ultimate load.

SIEGFRIED GROSS.

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