Mantz v. Kersting

• Decision Date: 14 October 1939
• Docket Number: No. 59-Y Civil.,59-Y Civil.
• Citation: 29 F. Supp. 706
• Court: U.S. District Court — Southern District of California
• Parties: MANTZ et al. v. KERSTING.

29 F. Supp. 706

MANTZ et al. v. KERSTING.

No. 59-Y Civil.

District Court, S. D. California, C. D.

October 14, 1939.

Joseph F. Westall, of Los Angeles, Cal., for plaintiffs.

Harris, Kiech, Foster & Harris by Ward D. Foster and Ford Harris, Jr., of Los Angeles, Cal., for defendant.

YANKWICH, District Judge.

Plaintiffs charge infringement by the defendants of Mantz Letters Patent No. 1,898,584, issued February 21, 1933, relating to a spring sash balance, and Mantz Letters Patent No. 2,128,007, issued August 23, 1938, relating to a combination hook and glider, to be used with a spring sash balance.

The art is old. Neither invention is primary. They must, therefore, be limited to the very structure described. Bridge v. Excelsior Co., 1881, 105 U.S. 618, 26 L.Ed. 1190; Boyd v. Janesville Hay-Tool Co., 1895, 158 U.S. 260, 267, 15 S.Ct. 837, 39 L.Ed. 973; Kokomo Fence Machine Company v. Kitselman, 1903, 189 U.S. 8, 23 S.Ct. 521, 47 L.Ed. 689; S. H. Brinton Co. et al. v. Mishcon, 1937, 2d Cir., 93 F. 2d 445, 449; Nye & Nissen v. Kasser Egg Process Co., 1938, 9 Cir., 96 F.2d 420, 423; and see my recent opinion in Delaney Patents Corp. v. Johns-Manville et al., D.C., 29 F.Supp. 431 decided on September 28, 1939.

The two claims of Letters Patent No. 1,898,584, of which infringement is charged, read:

"(1) In a spring sash balance, a housing, a rotatably adjustable axle mounted within said housing, a drum mounted on said axle, a spiral spring arranged within said drum and having its ends connected respectively to said drum and said axle and a circumferential bead projecting inwardly from the rear wall of the housing and surrounding the periphery of said drum for preventing the cable that winds on said drum from passing off the inner end of said drum.

"(2) In a spring sash balance, a housing, a rotatably adjustable axle mounted for operation therein, a drum mounted for operation on said axle, a spring arranged within said drum and having its ends connected respectively to said drum and axle, a flexible member connected to and adapted to wind onto said drum, the outer end of the periphery of said drum being provided with a circumferentially inclined face and a circumferential bead formed on the inner wall of the housing and surrounding the inner edge of the periphery of said drum for preventing the flexible member that winds onto said drum from riding off the inner end thereof."

It is clear that the elements of the combination are these: (1) A housing; (2) a rotatably adjustable axle; (3) a drum mounted on the axle; (4) a spring arranged within the drum with its end connected to the drum and axle; (5) a flexible member connected to and adapted to wind onto the drum; (6) the outer end of the periphery of the drum having a circumferentially inclined face; and (7) a circumferential bead formed on the inner wall of the housing, so as to prevent the flexible member that winds onto the drum from riding off.

The flexible member used in the structure, as manufactured, is a piano wire cable.

Sash balances have been in use for many years. The significant features of the Mantz sash balance can be best illustrated by a comparison with two other Mantz balances of which the patent in suit claims to be an improvement.

The patent in suit refers to them as United States Letters Patent 1,669,990, issued on May 15, 1928, and co-pending application filed by Mantz on July 25, 1928, Serial Number 295184.

The device disclosed by Mantz patent 1,669,990 was of the flat type, the face plate of which 10 is shown in Figure 1. The face plate supports a fixed pin 13 extending from it backwardly. The mechanism is affixed on pin 13 to the front plate. The pin supports the cable-carrying drums or spools 17 and 21. The first spool 17 is fixed to a rotatable sleeve 16 and on that sleeve is rotatably mounted a housing 20 containing spiral spring 27 fixed as shown in Figure 3 to the rotatable sleeve 16 at one end. The other end of the spring is affixed outside the housing 20. The cables from each of the drums 17 and 21 are spaced by discs 19 and extend down through openings 29 in the face plate, so that the cable connects through a hook 30 to one sash. This is done also with the second cable to the lower sash. Pin 13 which does not rotate is parallel to the plane of the window sash. At the rear end of the pin 13 is affixed a plate 25 held in position by a screw 26 in order to hold the various parts in place.

When the balances are installed, the springs are partially wound to put a certain tension in the spring, in order to balance the sash. The drums or spools 17 and 19 are adapted to support the cables without permitting them to run out. The cables are wound vertically, one above the other.

The specifications clearly contemplate the possibility of utilizing one spring for each drum, rather than a single spring which would operate two drums. One of the claimed advantages of the structure is that, being of the flat, level type, it made it unnecessary to cut away a portion of the wall behind the jamb to accommodate it.

In his specifications to Letters Patent 1,836,080, which is the patent issued on application No. 295,184 referred to in the patent in suit, Mantz claims the new structure as an improvement on the prior one.

The objects sought to be accomplished are: (1) A duplex spring sash balance which may be easily installed and removed in order to aid adjustment and repairs; (2) to provide a frictional resistance between the cable carrying drums or spools and the housing which results in a minimum tension in the spring, so that the sash will remain stationary in all positions. In a shallow housing 10, he has two rotatable axles 14 placed substantially vertically above each other. Outside of these axles, are fixed cable-carrying drums 15, which, like those in patent 1,669,990, receive the cables coiled in a vertical position. These drums are firmly fixed to the rotatable axles 14 and are separated from a spiral spring 22 by the front case of the housing 12. These springs are not in any housing which is rotatable on the axle 14, but one end of the spring is fixed to each axle. In between the cable-carrying drums 15 and the front plate 12 are fixed frictional spring fingers 21. There are shown in Figure 1 eight of these frictional fingers which are for the purpose not of adjusting the tension of the spiral spring, but of giving a frictional resistance. The tension is put into the springs by manually rotating these drums and then inserting a pin through an orifice 23 and an orifice 24 in the front and rear plates of this shallow housing, so that there will be a certain tension stored in these springs at the time that the balance is installed.

In the patent in suit, Mantz, as his specifications show, sought to improve and simplify the construction of the sash balances in his prior patents and other "similar forms of spring sash balances", to provide a sash balance having two separate drums on which the sash supporting the cables are wound, each drum inclosing a spiral spring. The cables are carried on the periphery of the drums in a single flat winding. To insure that the cables wind evenly on the drums without piling up or winding in two layers, means are provided consisting of circumferential flange 22 having an inclined face which is stated to cause the cables to wind evenly onto the drum. Aiding this achievement is a circumferential bead 24 pressed into the rear wall of the housing.

The regulation of the tension on the spiral springs is achieved by the rotatable axles 17 and one end of the spiral spring 25 attached to them, which may be rotated by inserting a screwdriver in a slot 30 and pressing in on a ratchet 28 which is spring-pressed by the spring 31 and rotating the axle 17 in either direction to wind or unwind the spring and thus regulate the tension as is desired.

The accused device has a housing, an axle mounted therein with a drum mounted on the axle, and a spiral spring within the drum having its ends connected to the drum and the axle, the drum having thereon one flange, and there being another spring, — frictionally resisting the rotation of the drum. The axle is firmly riveted to the cover and housing. A cable is wound on the drum. The leaf spring between the spiral spring and the drum resists the rotation of the drum by urging the coils of the spiral spring into frictional engagement with the housing.

In this device, several of the elements of the patented device are missing. It does not contain the rotatably adjustable axle mounted within a housing. It has an axle which is stationary, to which the spiral spring is attached. The difference in result is quite important. By means of the rotatably adjustable axle, it is possible, in the plaintiffs' device, to adjust, after installation, the tension of the spring by means of a disc which, as the specifications say, is: "provided on its edge with a series of radially disposed teeth 28, thereby forming a ratchet wheel and said disc is provided with a pair of arcuate openings 29 for the reception of the lugs 26. Formed in the center of disc 26 between the openings 29, is a small opening or slot 30, that is adapted to receive the point of a screw driver or like tool."

In the accused device, the exact tension of the springs is adjusted before assembly in a shop operation and not in the operation of the structure. Otherwise put, in the patented device, adjustment is achieved in the device itself. In the accused device, the adjustment is a factory process.

After the installation is completed, and the housing is riveted on, the spring cannot be adjusted either by rotating the axle or in any other manner.

Counsel say that the ratchet wheel and its function may be disregarded, as they are not in Claims 1 and 2, sued on. But without it, the structure is incomplete. A patentee may patent part of a structure in a combination, or claim it separately. See: Seymour v. Osborne, 1870, 11...