# US 10,118,307 B2 · Chain saw > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,118,307 B2 - Document ID: US10118307B2 - Status: Granted - Kind: B2 - Application number: 15/695,202 - Filed: 2017-09-05 - Published: 2017-12-21 - Granted: 2018-11-06 - Earliest claimed: 2014-04-29 - Assignees: Chervon (HK) Limited - Applicants: Chervon (Hk) Limited - Inventors: Toshinari Yamaoka; Fangjie Nie; Huixing Fu - Web page: https://patentgrep.com/patent/US10118307B2 ## CPC - B27B 17/12: Lubricating devices specially designed for chain saws - F04B 7/0088: {Sealing arrangements between the distribution members and the housing} - F04B 9/14: Pumps characterised by muscle-power operation {(hand-held spraying or dispensing apparatus using pumps or bulbs B05B11/00)} - F04B 15/02: the fluids being viscous or non-homogeneous - F04B 19/22: of reciprocating-piston type - F04B 53/10: Valves; Arrangement of valves - F04B 53/1002: {Ball valves} - F04B 53/14: Pistons, piston-rods or piston-rod connections - F04B 53/16: Casings; Cylinders; Cylinder liners or heads; Fluid connections - Y10T 83/707: By endless band or chain knife - B27B: SAWS FOR WOOD OR SIMILAR MATERIAL; COMPONENTS OR ACCESSORIES THEREFOR (saws specially adapted for pruning or debranching A01G3/08; sawing apparatus specially adapted for felling trees A01G23/091; features not restricted to a particular type of wood saw B23D, e.g. attaching saw blades B23D51/00; machine tool frames, beds, pillars or like members, in general B23Q1/01) - F04B: POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS (machines for liquids, or pumps, of rotary-piston or oscillating-piston type F04C; non-positive-displacement pumps F04D; pumping of fluid by direct contact of another fluid or by using inertia of fluid to be pumped F04F) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A chain saw has a fluid pump. The fluid pump has a pump rod, a pump core assembly defining a pumping channel, and a pump body. The pump core assembly has an inner pump core and an outer pump core. The pumping channel is formed at least by a first hole defined in the inner pump core and a second hole defined in the outer pump core and the first hole is in communication with the inlet and the outlet. The pump rod is arranged to do a straight reciprocating motion in the pumping channel along a first axis so as to force fluid to flow from the inlet to the outlet by passing through the first hole. ## Claims ### Claim 1 A chain saw, comprising: a motor, a chain having a plurality of blades driven by the motor, and a fluid pump for providing a lubricating fluid to the chain; wherein the fluid pump comprises: a pump rod; a pump core assembly defining a pumping channel; and a pump body defining an inlet, an outlet, and a cavity having an opening at one end; wherein the outlet is defined at an end of the cavity opposite to the opening and the inlet is defined between the opening and the outlet; wherein the pump core assembly comprises: an inner pump core disposed in the cavity, and an outer pump core coupled with the pump body at the opening; wherein the pumping channel is formed at least by a first hole defined in the inner pump core and a second hole defined in the outer pump core, and the first hole is in communication with the inlet and the outlet; and wherein the pump rod is arranged to have a straight reciprocating motion in the pumping channel along a first axis so as to force the lubricating fluid to flow from the inlet to the outlet by passing through the first hole. ### Claim 2 (depends on 1) The chain saw according to claim 1, wherein the inner pump core further defines a radial hole and the inlet communicates with the pumping channel by the radial hole. ### Claim 3 (depends on 2) The chain saw according to claim 2, further comprising a check valve assembly for preventing fluid from flowing from the outlet to the inlet, wherein the first hole comprises a communicating section for communicating with the radial hole and a first accommodating section for accommodating the check valve assembly and wherein the radius of the accommodating section is greater than the radius of the communicating section. ### Claim 4 (depends on 3) The chain saw according to claim 3, wherein the check valve assembly comprises a valve ball for blocking the first hole and a first bias member for biasing the valve ball towards the communicating section. ### Claim 5 (depends on 2) The chain saw according to claim 2, wherein the inner pump core defines a ring groove at an outside wall of the inner pump core and one end of the radial hole is arranged at the ring groove. ### Claim 6 (depends on 3) The chain saw according to claim 3, wherein the radius of the communicating section is approximately equal to the radius of the pump rod. ### Claim 7 (depends on 1) The chain saw according to claim 1, further comprising a sealing ring for preventing fluid from flowing along the pump rod wherein the sealing ring is disposed between the inner pump core and the outer pump core and the pump rod is arranged to pass through the sealing ring. ### Claim 8 (depends on 7) The chain saw according to claim 7, wherein the inner pump core comprises a protruding portion protruding along the first axis and the second hole comprises a second accommodating section for accommodating the protruding portion and the sealing ring. ### Claim 9 (depends on 8) The chain saw according to claim 8, wherein the sealing ring is arranged between the end face of the protruding portion and the end face of the second accommodating section. ### Claim 10 (depends on 1) The chain saw according to claim 1, further comprising a cap coupled with the pump rod at the outer end of the pump rod and a second bias member for biasing the cap to move away from the pump body. ### Claim 11 (depends on 1) The chain saw according to claim 1, wherein the motor drives the pump rod to move along the first axis.