A pump mechanism for vacuum sealing an airtight cavity formed by a container and a lid, including a bore having a first one-way seal allowing air from the airtight cavity to enter the bore and blocking air inside the bore from returning to the airtight cavity and a second one-way seal allowing air inside the bore to leave the bore without returning to the airtight cavity and blocking air outside of the bore from entering the bore, a piston disposed inside the bore, and a chamber of air enclosed by the bore, the first and second one-way seals, and the piston, wherein actuation of the piston in a first direction causes air to evacuate the airtight cavity and enter the chamber through the first one-way seal, and wherein actuation of the piston in a second direction causes air to exit the chamber through the second one-way seal.

A pump mechanism for vacuum sealing an airtight cavity formed by a container and a lid, including a bore having a first one-way seal allowing air from the airtight cavity to enter the bore and blocking air inside the bore from returning to the airtight cavity and a second one-way seal allowing air inside the bore to leave the bore without returning to the airtight cavity and blocking air outside of the bore from entering the bore, a piston disposed inside the bore, and a chamber of air enclosed by the bore, the first and second one-way seals, and the piston, wherein actuation of the piston in a first direction causes air to evacuate the airtight cavity and enter the chamber through the first one-way seal, and wherein actuation of the piston in a second direction causes air to exit the chamber through the second one-way seal.

An example apparatus to prevent side load in hydraulic override pumps includes a lever rotatably mounted to a support. The apparatus includes a pump cylinder rotatable about a first end of the pump cylinder. The apparatus also includes a pump rod operatively coupled to the lever to move within the pump cylinder based on rotation of the lever. The pump cylinder rotates when the pump rod moves within the pump cylinder.

An example apparatus to prevent side load in hydraulic override pumps includes a lever rotatably mounted to a support. The apparatus includes a pump cylinder rotatable about a first end of the pump cylinder. The apparatus also includes a pump rod operatively coupled to the lever to move within the pump cylinder based on rotation of the lever. The pump cylinder rotates when the pump rod moves within the pump cylinder.

A vacuum pump includes a hollow container that has a vacuum port and internal chamber walls. The vacuum port opens to an exterior of the container and the chamber walls define chambers that are in fluid communication with the vacuum port. There are flexible bladders disposed in the chambers. The flexible bladders include vents that open through the container to the exterior. A plunger in the container includes arms that extend into the chambers such that each of the flexible bladders is situated between one of the arms and one of the chamber walls. The plunger is moveable between a home position and an upstroke position to compress and deflate the flexible bladders via the vents and thereby change the volume of the flexible bladders. The change in the volume draws a vacuum through the vacuum port.

A three-stage compression air pump includes a pump head and a pumping device. The pumping device includes first and second cylinders and a plunger. The first cylinder is connected with the pump head and coupled to a first piston moving in the second cylinder. The second cylinder includes a first end cap and a second end cap respectively coupled to the two ends thereof. The first cylinder is inserted through the first end cap. The second end cap defines an orifice allowing outside air to flow into the second cylinder and includes a one-way valve preventing the air in the second cylinder from flowing outside the three-stage compression pump. The plunger is inserted in and movably coupled to the first cylinder and coupled to a second piston moving in the first cylinder and connected with the second end cap. The plunger is inserted through the first piston.

A three-stage compression air pump includes a pump head and a pumping device. The pumping device includes first and second cylinders and a plunger. The first cylinder is connected with the pump head and coupled to a first piston moving in the second cylinder. The second cylinder includes a first end cap and a second end cap respectively coupled to the two ends thereof. The first cylinder is inserted through the first end cap. The second end cap defines an orifice allowing outside air to flow into the second cylinder and includes a one-way valve preventing the air in the second cylinder from flowing outside the three-stage compression pump. The plunger is inserted in and movably coupled to the first cylinder and coupled to a second piston moving in the first cylinder and connected with the second end cap. The plunger is inserted through the first piston.

A hand grip mechanism includes a first member, a second member connected to the first member in a vertically moveable manner, a spring providing a biasing force to lower the second member with respect to the first member, and a hand grip configured by two grip links, each including a grip rotatably connected to the first member, a link rotatably connected to the second member below a connecting portion between the first member and the grip, and first and second connecting shafts each connecting the grip and the link below a connecting portion between the second member and the link. By a pressing operation to squeeze the hand grip against the biasing force of the spring, the grip and link in each grip link rotate relative to each other about the first connecting shaft during initial movement and about the second connecting shaft during final movement.

A hand grip mechanism includes a first member, a second member connected to the first member in a vertically moveable manner, a spring providing a biasing force to lower the second member with respect to the first member, and a hand grip configured by two grip links, each including a grip rotatably connected to the first member, a link rotatably connected to the second member below a connecting portion between the first member and the grip, and first and second connecting shafts each connecting the grip and the link below a connecting portion between the second member and the link. By a pressing operation to squeeze the hand grip against the biasing force of the spring, the grip and link in each grip link rotate relative to each other about the first connecting shaft during initial movement and about the second connecting shaft during final movement.

A vacuum pump includes a hollow container that has a vacuum port and internal chamber walls. The vacuum port opens to an exterior of the container and the chamber walls define chambers that are in fluid communication with the vacuum port. There are flexible bladders disposed in the chambers. The flexible bladders include vents that open through the container to the exterior. A plunger in the container includes arms that extend into the chambers such that each of the flexible bladders is situated between one of the arms and one of the chamber walls. The plunger is moveable between a home position and an upstroke position to compress and deflate the flexible bladders via the vents and thereby change the volume of the flexible bladders. The change in the volume draws a vacuum through the vacuum port.