US2239062A - Spring structure - Google Patents

Description

April 22, 1941. E. s. TALLMADGE SPRING STRUCTURE Filed June 3, 1940 2 Sheets-Sheet 1 INVENTOR. EVERETT s. TALLMADGE WM M 1 ATTORNEYS April 22, 1941.

E. S. TALLMADGE SPRING STRUCTURE Filed June 3, 1940 2 Sheets-Sheet 2 l6 l7 l8 FIG.'5.

FIG.6.

FIG]

FIG.9.

INVENTOR. VERETT s. TALLMADGE A T TORNE YS Patented Apr. 22, 1941 SPRING STRUCTURE Everett S. Tallmadge, Robblnsdale, Minn., assignor to Edward Minn.

W. Schlappritzi, Minneapolis,

Application June 3, 1940, Serial No. 338,623

11 Claims.

This invention relates generally to spring structures and refers more particularly to multiple leaf spring structures.

One of the essential objects of the invention is to provide a spring structure of this type wherein supporting or secondary spring leaves of predetermined configuration are used against or in combination with longer spring leaves, either main or secondary, to reinforce the main or adjacent leaves so that the structure as a whole will function properly without breakage or failure to carry and cushion a given load.

Another object is to provide a spring struc-- ture wherein the secondary spring leaf reinforcement bridges or spans the point or points of the main or adjacent leaves where breakage or failure would ordinarily occur and is provided at its free end with means for definitely relieving the main or adjacent leaves of any concentration of strain or of any piercing or shearing action tending to cause failure or breakage.

Another object is to provide a spring structure wherein the means just mentioned enhances the pliability, flexibility and spring action of the leaves so that the structure functions better and more efficiently. 1

Another object is to provide a spring structure that is simple in construction, economical to manufacture, and reliable in operation.

Other objects, advantages and novel details of construction of this invention will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawings, wherein:

Figure 1 is a perspective view of a spring structure embodying my invention;

Figure 2 is a fragmentary perspective view thereof;

Figure 3 is a fragmentary bottom plan view of the structure shown in Figure 2;

Figure 4 is a sectional view taken substantially on the line L4 of Figure 3;

Figure 5 is a plan view of a slight modification;

Figure 6 is a view similar to Figure 5 but show-- ing another modification;

Figure 7 is a view similar to Figures 5 and 6 but showing a further modification;

Figures 8 and!) are fragmentary plan views of a blank from which the reinforcing leaves are formed, and showing the manner in which such reinforcing leaves can be cut from the blank.

The reinforcement mentioned is intended primarily for use as a support for main leaves of bed springs, cushion springs, etc., however it is applicable to any leaf spring structure wherein supporting or secondary spring leaves are desired and may be any suitable shape or configuration depending upon the shape or configuration of the main or adjacent spring leaves with which it is used.

In the accompanying drawings, A is the main frame, B is the auxiliary frame, C are the main spring leaves, and D are the secondary spring leaves of a spring structure embodying my invention.

As shown, the main frame A is substantially rectangular shape and is formed of tubing. The elements III are reinforcing bars extending between opposite sides of the frame, while the elements l I are reinforcing bars extending between opposite ends of the frame.

The auxiliary frame B substantially conforms in configuration to the main frame and is substantially parallel thereto. Preferably this auxiliary frame is formed of strips of spring steel and includes numerous tie bars l2 that extend in pairs between opposite sides of said frame.

The main spring leaves C are substantially cshape in configuration and are arranged in rows along the reinforcing bars H between the main and auxiliary frames A and B. The lower ends of such leaves C are rigidly secured by rivets [3 or the like to the reinforcing bars II, while the upper ends of said leaves are secured by rivets I4 to the tie bars l2. Preferably each spring leaf C is substantially equal in width and is secured to a pair of tie bars l2.

As shown, the secondary spring leaves D are on the underside of the main leaves C and extend between the latter and the reinforcing bars ll. However, it is apparent that such leaves D may be used on the upperside, inside, outside, or in surface-to-surface contact with any portion desired of the main or adjacent leaves C. In the present instance, the rivets I: that serve as securing means for the main leaves C also serve as securing means for the secondary leaves D. By referring to Figures 2 and 3, it will be noted that the secondary leaves D are narrower than but are centered with respect to the main leaves C, however it is to be understood that such secondary leaves may if desired be equal in width to or wider than the main leaves C. By referring to Figure 4 it will be noted that the secondary leaves D conform in curvature to and bear firmly in surface-to-surface relation against the main leaves C. It will also be noted that the secondary leaves D are of sufiicient length to bridge or span the critical point of the main 6 I have illustrated another modification wherein' the three tongues ll, 20 and II, respectively, are not uniform in configuration or length. This difference in length gives greater distribution of strains. In Figure 7 I have illustrated another modification wherein only two symmetrical tongues 22 and 23, respectively, are employed. In each instance, however, the multiple tongues distribute the strains across the width of the supported leaves C and thereby eliminate or reduce localized stresses and increase the durability or the load that can be safely carried. Actually the multiple tongue feature of the secondary.

leaves provides more flexibility since the multiple tongues'are more pliable and enhance at spaced points the spring action in the structure. Thus, there is no concentration of strain at or near any one point of the secondary leaves tending to cause failure in the supported leaves. Likewise, there is no tendency-of the secondary leaves to pierce or punch through the supported leaves or to produce any shearing action. As long'as the secondary leaves D have two or more tongues at their free ends and are of sufficient length to bridge or span the critical points of the main spring leaves C, the secondary leaves D and the tongues at the free ends thereof may be any shape desired.

Due to the multiple tongue feature, the sec, ondary leaves D may be readily formed from blanks or strip stock with little or no waste, as

illustrated in Figures 8 and 9. By referring to these figures it will be noted that substantially one zigzag cut across the blank will provide two adjacent sets of tongues. The blanks may then be cut at 30 and 3| (Figure 8), or'at l2 and 33 (Figure 9) as desired, to provide the secondary leaves. Thus, in making leaves with tongues at one end thereof, the. material'can be conserved as the pieces can be blanked in pairs without waste of material from the notches or recesses between the tongues. When blanked in this way from material having a grain parallel with the side edges of the material, as, for example, strip steel, the longitudinal direction of the grain is kept within the tongues, consequently they are materially strengthened.

What I claim as my invention is:

1. A spring structure having upper and lower frame members, and two leaf springs secured in overlapping relation to one of said frame. members and extending toward the other of said frame members, one of said leaf springs being substantially C-shape in configuration and secured to the other of said frame members, the second leaf spring having surface-'to-surface contact throughout its length with the C-shaped spring and having a plurality of laterally spaced tongues at its free end.

2. A spring structure having upper and lower framemembers, and two leaf springs secured in I frame members, one of said leaf springs being substantially c-shape in configuration and secured to the other of said frame members, the second leaf spring having surface-to-surface contact throughout its length with the c-shaped spring and terminating in a plurality of laterally spaced substantially triangular shaped tongues.

3. A spring structure having upper and lower frame members, a leaf spring extending between and secured to said frame members, and a secondary leaf spring having" surface-to-surface' contact throughout its length with the first mentioned spring, said secondary spring being secured to one of said frame members and free of the other, the free end of said secondary spring consisting of a plurality of laterally spaced pointed tongues.

4. A spring structure having upper and lower frame members, a leaf spring extending between and secured to said frame members, and a secondary leaf spring having s'urface-to-surfacecontact throughout its length with the first mentioned spring, said secondary spring being secured to one of saidframe members and free of the other, the free end of said secondary spring having a plurality of laterally spaced pliable portions.

5. A spring structure having upper and lower frame members, a leaf spring extending between and terminally secured to said frame members, and a secondary leaf spring secured to the lower frame member and having surface-to-surface contact throughout its length with the first mentioned leaf spring, the secondary spring spanning a critical point of the first mentioned spring and provided between said point and the upper frame member with a free end having a plurality of laterally spaced substantially triangular shaped tongues.

6. A spring structure having upper and lower frame members, a leaf spring extending between and secured to said frame members, and a secondary leaf spring secured to one of said frame members and free of the other, said secondary spring being in surface-to-surface contact throughout its length with the leaf spring aforesaid and provided at its free end with a plurality of pliable substantially triangular portions.

7. A spring structure having upper and lower frame members, a leaf spring extending between and terminally secured to said. frame members, and a secondary leaf spring having surface-tosurface contact throughout its length with theleaf spring aforesaid and spanning a critical point thereof adjacent the lower frame member, :said secondary spring being provided between said frame members with a free end having endwise projecting laterally spaced tongues.

8. A spring structure having upper and lower frame members, a leaf spring extending between and secured to said frame members, asecondary leaf spring having surface-to-surface contact throughout its length withand spanning a ,critical point of the spring aforesaid,-the secondary spring being secured to oneof the frame members and free of the other, the free end of the secondary spring consisting of a plurality of laterally spaced pliable endwise projecting substantially triangular portions for relieving the first mentioned spring of any concentration of strain.

9. A spring structure having upper and lower frame members, and two leaf springs secured in overlapping relation to one of said frame members and extending toward the other of said frame memberaoneof said leaf springs being substantially c-shape in configuration and secured to the other of said frame members, the second leaf spring having surface-to-surface contact throughout its length with the c-shaped spring and provided at its free end with a plurality of laterally spaced tongues, the second leaf spring spanning a critical point of the c shaped spring adjacent the lower frame member and relieving the c-shaped spring of concentration of strains or piercing or shearingaction at said critical point. 7

10. A spring structure having upper and lower frame members, a main leaf spring extending between and secured to said frame members, and a secondary leaf spring having surface-tosurface contact throughout its length with the main spring, the secondary spring being secured at one end to the lower frame member and provided between said frame members with a free end having endwise projecting laterally spaced 20 tongues, said secondary spring spanning a critical point of the main spring adjacent the lower frame member and relieving the main spring of concentration of strains or piercing or shearing action at said critical point. 7

- -11. A spring structure having upper and lower frame members, a main leaf spring extending between and secured to said frame members, and a secondary leaf spring of less length than the main spring having surface-to-surface contact throughout its length with the main spring, the secondary spring being secured at one end to one of the elements aforesaid and provided between said frame members with a free end having laterally spaced tongues, said secondary spring spanning a critical point of the main spring adiacent the lower frame member and relieving the main spring of concentration of strains or piercing or shearing action at said critical point.

8. TAILMADGE.

Images