# US 4,472,953 A · Pin-type lock with axial split cylinder and/or plug > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,472,953 A - Document ID: US4472953A - Status: Granted - Kind: A - Application number: 06/463,038 - Filed: 1983-02-01 - Granted: 1984-09-25 - Earliest claimed: 1983-02-01 - Assignees: Emhart Industries, Inc. - Inventors: Arnold C. Gater - Web page: https://patentgrep.com/patent/US4472953A ## CPC - E05B 27/00: Cylinder locks {or other locks} with tumbler pins or balls that are set by pushing the key in - E05B 27/0007: {Rotors} - E05B 27/0014: {Stators (cylinder lock casings in general E05B9/04)} - Y10T 70/7672: Cylinder - Y10T 70/7684: Plug - E05B: LOCKS; ACCESSORIES THEREFOR; HANDCUFFS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A pin-type lock cylinder telescopes a rotatable lock plug with a multiplicity of generally axially and radially aligned pin holes formed in each and pins in the pin holes controlled by a key inserted axially into the plug for properly radially positioning the pins and permitting unlocking rotation of the plug. At least one of the cylinder and plug, and preferably both, are axially split members formed of generally diametrically opposed parts with the axial split passing through the axially aligned pin holes. One of the split member parts having an axially and radially flat surface extending continuously along said pin holes and forming one side of the pin holes with axial spacing therebetween, the other of the split member parts having axially spaced and radially extending grooves, preferably D-shaped cross section grooves, formed therein to complete the pin holes. The assembled cylinder pin hole grooves may face diametrically oppositely from the plug pin hole grooves, and the cylinder pin holes may be of slightly larger cross sectional dimension than the plug pin holes. ## Claims ### Claim 1 In a lock of the general type having a lock cylinder telescoping a rotatable lock plug with a multiplicity of generally axially and radially aligned pin holes formed in each, cylinder and plug pins in the pin holes controlled by a key inserted axially into the plug properly radially positioning the pins and permitting unlocking rotation of the plug; the improvements including: at least one of said cylinder and plug being an axially split member formed of at least generally diametrically opposed parts with the axial split passing through said axially aligned pin holes, one of said split member parts having an axially and radially flat surface extending continuously along said pin holes and forming one side of said pin holes with axial spacing therebetween, the other of said split member parts having axially spaced and radially extending grooves formed therein to complete said pin holes. ### Claim 2 (depends on 1) In a lock as defined in claim 1 in which said grooves forming said pin holes in said other split member part are D-shaped in cross section with a flat of said D-shaped grooves mating with said flat surface of said one split member part. ### Claim 3 (depends on 1) In a lock as defined in claim 1 in which both of said cylinder and plug are axially split members with one of said split member parts of each having said flat surface and the other of said split member parts of each having said grooves. ### Claim 4 (depends on 1) In a lock as defined in claim 1 in which both of said cylinder and plug are axially split members with one of said split member parts of each having said flat surface and the other of said split member parts of each having said grooves; and in which said grooves of the other of said split member parts of each are D-shaped in cross section having flats thereon mating with said flat surfaces of said one of said split member parts of each. ### Claim 5 (depends on 1) In a lock as defined in claim 1 in which both of said cylinder and plug are axially split members with one of said split member parts of each having said flat surface and the other of said split member parts of each having said grooves; and in which said cylinder pin holes measured in cross section are slightly larger than said plug pin holes. ### Claim 6 (depends on 1) In a lock as defined in claim 1 in which both of said cylinder and plug are axially split members with one of said split member parts of each having said flat surface and the other of said split member parts of each having said grooves; in which said grooves of the other of said split member parts of each are D-shaped in cross section having flats thereon mating with said flat surfaces of said one of said split member parts of each; and in which said cylinder pin holes measured in cross section are slightly larger than said plug pin holes. ### Claim 7 (depends on 1) In a lock as defined in claim 1 in which both of said cylinder and plug are axially split members with one of said split member parts of each having said flat surface and the other of said split member parts of each having said grooves; and in which said cylinder grooves face diametrically opposite from said plug grooves. ### Claim 8 (depends on 1) In a lock as defined in claim 1 in which both of said cylinder and plug are axially split members with one of said split member parts of each having said flat surface and the other of said split member parts of each having said grooves; in which said cylinder grooves face diametrically opposite from said plug grooves; and in which said grooves of the other of said split member parts of each are D-shaped in cross section having flats thereon mating with said flat surfaces of said one of said split member parts of each. ### Claim 9 (depends on 1) In a lock as defined in claim 1 in which both of said cylinder and plug are axially split members with one of said split member parts of each having said flat surface and the other of said split member parts of each having said grooves; in which said cylinder grooves face diametrically opposite from said plug grooves; and in which said cylinder pin holes measured in cross section are slightly larger than said plug pin holes. ### Claim 10 (depends on 1) In a lock as defined in claim 1 in which both of said cylinder and plug are axially split members with one of said split member parts of each having said flat surface and the other of said split member parts of each having said grooves; in which said cylinder grooves face diametrically opposite from said plug grooves; in which said grooves of the other of said split member parts of each are D-shaped in cross section having flats thereon mating with said flat surfaces of said one of said split member parts of each; and in which said cylinder pin holes measured in cross section are slightly larger than said plug pin holes. ### Claim 11 (depends on 1) In a lock as defined in claim 1 in which both of said cylinder and plug are axially split members with one of said split member parts of each having said flat surface and the other of said split member parts of each having said grooves; and in which said cylinder and plug pins are round cross section pins. ### Claim 12 (depends on 1) In a lock as defined in claim 1 in which both of said cylinder and plug are axially split members with one of said split member parts of each having said flat surface and the other of said split member parts of each having said grooves; in which said grooves of the other of said split member parts of each are D-shaped in cross section having flats thereon mating with said flat surfaces of said one of said split member parts of each; and in which said cylinder and plug pins are round cross section pins.