Coilable rule and replacement cartridge therefor

Claim 2

A replacement cartridge for a coilable rule comprising a form-sustaining spool mounting a coiled measuring blade, said spool having a centrally disposed aperture, a removable hub received within said aperture, a recoil spring having one end secured to said hub and the other end secured to the inner end of said measuring blade, and a keeper for maintaining the measuring blade, the recoil spring and the hub in fixed relation relative to each other and to the spool, and means for securing said keeper against rotation relative to said spool.

Claim 3

A replacement cartridge for a coilable rule comprising a form-sustaining spool mounting a coiled measuring blade, said spool having a centrally disposed aperture, a removable hub received within said aperture, a recoil spring having one end secured to said hub and the other end secured to the inner end of said measuring blade, and a keeper for maintaining the measuring blade, the recoil spring and the hub in fixed relation relative to each other and to the spool, and means for securing said keeper against rotation relative to said spool.

Claim 4

A replacement cartridge for a coilable rule comprising a form-sustaining spool mounting a coiled measuring blade, said spool having a centrally disposed aperture, a removable hub received within said aperture, a recoil spring having one end secured to said hub and the other end secured to the inner end of said measuring blade, and a keeper for maintaining the measuring blade, the recoil spring and the hub in fixed relation relative to each other and to the spool, and means for securing said keeper against rotation relative to said spool.

Claim 5

The replacement cartridge of claim 1 wherein a ledge extends between the side walls of the spool, said ledge mounting the coiled measuring blade thereon.

Claim 6

The replacement cartridge of claim 1 wherein said keeper provides a pair of outer arms resiliently engageable with the outer surface of said coiled measuring blade.

Claim 7

The replacement cartridge of claim 3 wherein the spool is provided with side walls extending beyond the coiled measuring blade and said pair of outer arms snap over the edge of one of said side walls to retain the keeper on the spool.

Claim 8

The replacement cartridge of claim 1 wherein a noncircular central recess is provided in the end of said hub and a mating noncircular projection on said keeper is engaged in said recess to non-rotatably fix the keeper relatively to said hub.

Claim 9

In a measuring device of the coilable rule type having a casing comprising a pair of casing halves defining a chamber therein, a recoil spring received in the chamber and a coilable measuring blade connected to said spring to be retracted into coiled position in the chamber under the bias of said recoil spring and extended through an opening in said casing against the bias of said recoil spring; the improvement comprising a removable spool assembly incorporating a spool upon which said blade is coiled, and a hub member rotatably mounting said spool and to which the inner end of the recoil spring is secured for simultaneous removal and installation of said spool assembly, blade and spring in said casing, said casing and the ends of said hub member being provided with mating recess and projection means to mount said hub member in said Casing and to fix said hub member against rotation relative to said casing under the bias of the recoil spring.

Claim 10

In a measuring device of the coilable rule type having a casing comprising a pair of casing halves defining a chamber therein, a recoil spring received in the chamber and a coilable measuring blade connected to said spring to be retracted into coiled position in the chamber under the bias of said recoil spring and extended through an opening in said casing against the bias of said recoil spring; the improvement comprising a removable spool assembly incorporating a spool upon which said blade is coiled, and a hub member rotatably mounting said spool and to which the inner end of the recoil spring is secured for simultaneous removal and installation of said spool assembly, blade and spring in said casing, said casing and the ends of said hub member being provided with mating recess and projection means to mount said hub member in said Casing and to fix said hub member against rotation relative to said casing under the bias of the recoil spring.

Claim 11

The device of claim 6 wherein the recess means is provided in the ends of said hub member and the projection means is a truncated stud centrally disposed on a wall of one of said casing halves.