American Can Co. v. Hedstrom

29 F.2d 804, 1928 U.S. App. LEXIS 2810
CourtCourt of Appeals for the Seventh Circuit
DecidedDecember 22, 1928
DocketNo. 4033
StatusPublished

This text of 29 F.2d 804 (American Can Co. v. Hedstrom) is published on Counsel Stack Legal Research, covering Court of Appeals for the Seventh Circuit primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
American Can Co. v. Hedstrom, 29 F.2d 804, 1928 U.S. App. LEXIS 2810 (7th Cir. 1928).

Opinion

PAGE, Circuit Judge.

December 10, 1925, appellant-plaintiff sued to compel conveyance to it of letters patent No. 1,518,791 (here called B) by G. W. Hedstrom, inventor, and Peter W. Eulford, assignee of a half interest therein. Hedstrom died and his widow Olga and Eulford are appellees (called defendants).

Hedstrom and Eulford, by written instrument dated April 5,1924, assigned to appellant letters patent Ño. 1,472,417 (here called A), “together with the invention therein described, and all rights of action and claims thereunder existing at the date hereof.” The instrument also contained the following: “Grantors further agree to execute upon request and without further consideration any and all application papers and assignments to the American Can Company upon improvements that have or may hereafter be made by said grantors upon the said Drying Machine in said letters patent, and particularly upon a certain improvement illustrated in a sketch dated November 27, 1922, signed by Gustav W. Hedstrom.” Application for B was then pending but was not disclosed. B was issued December 9, 1924.

Plaintiff’s contention is that B is an improvement within the terms of the assignment. Defendants contend that B is wholly different from A, and that they were only obligated to assign improvements upon the specific drying machine covered by A.

The bill was dismissed for want of equity.

Both A and B are inventions relating to ends used in making tin cans. A can end has its edge turned down and in, forming a groove into which a sealing compound is placed for sealing purposes when the ends are put onto the body of the can. The proper drying of that compound is difficult to ac[805]*805complish, and there were various devices used unsuccessfully before Hedstrom entered the field, as inventor, to solve the problem. Two of the former machines and the reasons why they were not commercially successful are described, viz.: “One of these earlier constructions was the long box dryer having a chain traveling through an oven on which the can ends were fed flat, one behind the other. At times, can ends would overlap and the construction required considerable floor space, which rendered it almost impossible to operate satisfactorily commercially. Another construction * * * was the lifting of the can ends by two threaded posts vertically discharging the ends at the top, the ends falling down a chute and stacking up so that operators could pick them out of the chute. This type of dryer minimized drying time and caused excessive heat to be applied, blistering the lining compound.”

It thus appears that one of the serious problems was to economize in -floor space, over which the ends traveled on the endless chain,, and yet retain a sufficient length of travel so that proper drying could be accomplished without the blistering temperature required when the threaded posts only were used.

Hedstrom, in A, undertook to solve that problem by housing the moving parts of his device in a cylindrical shell, into which the drying heat was introduced from the bottom. Below is the plan shown in Figure 3 of A:

Although A discloses three forms of invention, the first only will be sufficient for our purposes.

In Figure 3, 10 is the housing shell, around the inner side of which, but not shown, is a screw thread 11. 13 is an. inner member, around the outer side of which, but not shown, is a screw thread 15. C is a can end, resting upon 11 and 15. It bridges the space between 10 and 13. To accommodate different sizes of ends, 13 is lifted out and a larger or smaller 13 is inserted, as required. 28 is a power pinion, that meshes with the teeth 27 on the large gear wheel or disk 20, not shown. 19 are posts set in the disk 20, and so positioned that they contact with the edges of the can ends at a point off their geometric center. 18 is a chute through which can ends are fed into the stacks at 17, not shown.

Through the coasting of these elements, 28 turns 27. 27 carries through the space between 10 and 13 the eight posts 19, which by contacting with the edges of the can ends, rotate the eight stacks of ends and move them through the screw threads, so that they pass around the inside of 10 and at the same time are moved up to the top of the dryer and of the threads, where they are discharged by a method not a part of A. By this, Hed-strom seems to have been the first to combine the elements of distance, time, and heat, so as to get the satisfactory commercial results through the use of the screw threads to obtain the upward and forward movement.

Below is Figure 4 of B, showing a transverse section of the device:

54 is the housing shell. 32 is the power pinion, that meshes with the teeth on the large gear wheel or disk 29. G are can ends resting upon and carried by the screw threads on two posts 10-10, attached to 29. 35 is an unthreaded post attached to 29 between and radially inside of the posts 10-10, and serves as a wall to keep the can ends upon the screw threads. 15 is a divider-like device, by which the posts 10-10 may be moved together or apart, to earry different sizes of can ends. 85 (not shown) is an opening [806]*806in the housing shell, through which the can ends are fed into the machine over the guide ribs 86. 79 is a chute. Concerning the discharge of can ends into that chute, the specification says only: “Any suitable kick-off means may be employed for removing the can ends from the upper lifter shafts to cause them to slide into the chute 79.”

Through the coacting of these elements, 32 turns 29, and carries the sixteen screw-threaded posts 10 and the eight stacks of •can ends C around and inside of the housing shell 54. The connection between the posts 10 and 29 is such that the posts revolve in the same direction, but, as to the can ends between them, they revolve in opposite directions, thereby revolving the can ends as they are earned to the top of the machine and the threads, where they are discharged at 79. The drying heat is introduced from below.

Analyzing A and B, we find the following:

Of A in December, 1922, and of B, in December, 1923, Hedstrom said: “I * * * have invented certain new and useful improvements in drying machines.”

The specification in A said: “This invention relates to improvements in drying machines * * * and is herein shown as designed more especially for drying the thin film of sealing medium, such as rubber compound, in the bottoms of the annular grooves of can ends, there placed for the purpose of sealing the joint between the can body and ends.”

In B, it is said: “This invention relates to improvements in drying machines for drying the thin coatings of sealing compound on the flanges of can ends, there placed for the purpose of insuring the sealing of the joint between the can body and the can ends when the grooved ends are seamed over the body of the can.” ,

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Bluebook (online)
29 F.2d 804, 1928 U.S. App. LEXIS 2810, Counsel Stack Legal Research, https://law.counselstack.com/opinion/american-can-co-v-hedstrom-ca7-1928.