# US 10,371,203 B2 · Cap for motion guide apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,371,203 B2 - Document ID: US10371203B2 - Status: Granted - Kind: B2 - Application number: 16/082,405 - Filed: 2017-03-23 - Published: 2019-04-11 - Granted: 2019-08-06 - Earliest claimed: 2016-03-25 - Assignees: Thk Co., Ltd. - Applicants: Thk Co., Ltd. - Inventors: Hiroyuki Kishi; Satoshi Kashiwagura; Ryuji Furusawa; Atsuhiro Tanaka - Web page: https://patentgrep.com/patent/US10371203B2 ## CPC - F16C 29/08: Arrangements for covering or protecting the ways {(protective coverings for parts of machine tools B23Q11/08)} - F16C 29/005: {Guide rails or tracks for a linear bearing, i.e. adapted for movement of a carriage or bearing body there along} - F16C 29/0647: {with load directions in X-arrangement} - F16C 29/0671: {with balls} - F16C 2240/60: Thickness, e.g. thickness of coatings - F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS ## Abstract A cap for a motion guide apparatus which can reduce generation of a burr and can also increase the fixing force. The cap of the present invention is for blocking a fastening member insertion hole of a guide rail of a motion guide apparatus. The cap includes a disc-shaped top surface portion, a cylindrical side surface portion hanging down from the top surface portion, and a plurality of protrusions provided on an outer peripheral surface of the side surface portion. The plurality of protrusions is apart from each other in a circumferential direction on the outer peripheral surface of the side surface portion, and is present at an upper end portion, or from the upper end portion to an axially middle portion, of the outer peripheral surface. A thickness of the side surface portion between the protrusions is less than a thickness of the top surface portion. ## Claims ### Claim 1 A cap for blocking a fastening member insertion hole of a guide rail of a motion guide apparatus, the cap for a motion guide apparatus comprising: a disc-shaped top surface portion; a cylindrical side surface portion hanging down from the top surface portion; and a plurality of protrusions provided on an outer peripheral surface of the side surface portion, wherein the plurality of protrusions is apart from each other in a circumferential direction on the outer peripheral surface of the side surface portion, and is present at an upper end portion, or from the upper end portion to an axially middle portion, of the outer peripheral surface, a thickness of the side surface portion between the protrusions is less than a thickness of the top surface portion, the top surface portion includes a center portion, and a peripheral portion thinner than the center portion, and the peripheral portion is thinner than the center portion within an entire area of the ring-shaped peripheral portion. ### Claim 2 (depends on 1) The cap for a motion guide apparatus according to claim 1, wherein a ring-shaped groove is provided at an edge of an undersurface of the top surface portion. ### Claim 3 (depends on 2) The cap for a motion guide apparatus according to claim 2, wherein the upper end portion of the outer peripheral surface of the side surface portion is provided with a flange to be placed on a chamfered portion of the fastening member insertion hole. ### Claim 4 (depends on 3) The cap for a motion guide apparatus according to claim 3, wherein a chamfered portion of an arc shape in cross section is provided on a top surface of the flange. ### Claim 5 (depends on 2) The cap for a motion guide apparatus according to claim 2, wherein a height of the protrusion from a top surface of the top surface portion to a lower end of the protrusion is equal to or greater than one-half an overall height of the cap. ### Claim 6 (depends on 2) The cap for a motion guide apparatus according to claim 2, wherein, of an entire circumference of the outer peripheral surface of the side surface portion, a total area where the plurality of protrusions comes into contact with the fastening member insertion hole is equal to or greater than 20% and equal to or less than 60%. ### Claim 7 (depends on 2) The cap for a motion guide apparatus according to claim 2, wherein the thickness of the side surface portion between the protrusions is less than the thickness of the center portion of the top surface portion. ### Claim 8 (depends on 7) The cap for a motion guide apparatus according to claim 7, wherein the thickness of the side surface portion between the protrusions is equal to or greater than a thickness of the peripheral portion of the top surface portion. ### Claim 9 (depends on 7) The cap for a motion guide apparatus according to claim 7, wherein the upper end portion of the outer peripheral surface of the side surface portion is provided with a flange to be placed on a chamfered portion of the fastening member insertion hole. ### Claim 10 (depends on 9) The cap for a motion guide apparatus according to claim 9, wherein a chamfered portion of an arc shape in cross section is provided on a top surface of the flange. ### Claim 11 (depends on 7) The cap for a motion guide apparatus according to claim 7, wherein a height of the protrusion from a top surface of the top surface portion to a lower end of the protrusion is equal to or greater than one-half an overall height of the cap. ### Claim 12 (depends on 7) The cap for a motion guide apparatus according to claim 7, wherein, of an entire circumference of the outer peripheral surface of the side surface portion, a total area where the plurality of protrusions comes into contact with the fastening member insertion hole is equal to or greater than 20% and equal to or less than 60%. ### Claim 13 (depends on 1) The cap for a motion guide apparatus according to claim 1, wherein the upper end portion of the outer peripheral surface of the side surface portion is provided with a flange to be placed on a chamfered portion of the fastening member insertion hole. ### Claim 14 (depends on 13) The cap for a motion guide apparatus according to claim 13, wherein a chamfered portion of an arc shape in cross section is provided on a top surface of the flange. ### Claim 15 (depends on 14) The cap for a motion guide apparatus according to claim 14, wherein a height of the protrusion from a top surface of the top surface portion to a lower end of the protrusion is equal to or greater than one-half an overall height of the cap. ### Claim 16 (depends on 14) The cap for a motion guide apparatus according to claim 14, wherein, of an entire circumference of the outer peripheral surface of the side surface portion, a total area where the plurality of protrusions comes into contact with the fastening member insertion hole is equal to or greater than 20% and equal to or less than 60%. ### Claim 17 (depends on 13) The cap for a motion guide apparatus according to claim 13, wherein a height of the protrusion from a top surface of the top surface portion to a lower end of the protrusion is equal to or greater than one-half an overall height of the cap. ### Claim 18 (depends on 13) The cap for a motion guide apparatus according to claim 13, wherein, of an entire circumference of the outer peripheral surface of the side surface portion, a total area where the plurality of protrusions comes into contact with the fastening member insertion hole is equal to or greater than 20% and equal to or less than 60%. ### Claim 19 (depends on 1) The cap for a motion guide apparatus according to claim 1, wherein a height of the protrusion from a top surface of the top surface portion to a lower end of the protrusion is equal to or greater than one-half an overall height of the cap. ### Claim 20 (depends on 1) The cap for a motion guide apparatus according to claim 1, wherein, of an entire circumference of the outer peripheral surface of the side surface portion, a total area where the plurality of protrusions comes into contact with the fastening member insertion hole is equal to or greater than 20% and equal to or less than 60%.