US 11,919,758 B2
Double acting rapid lift auxiliary valve assembly for a hydraulic jack
Daniel Kunau, Boone, CO (US)
Assigned to Gaither Tool Company, Inc., Jacksonville, IL (US)
Filed by Gaither Tool Company, Inc., Jacksonville, IL (US)
Filed on May 25, 2022, as Appl. No. 17/824,870.
Claims priority of provisional application 63/192,737, filed on May 25, 2021.
Prior Publication US 2023/0009283 A1, Jan. 12, 2023
Int. Cl. B66F 3/42 (2006.01)
CPC B66F 3/42 (2013.01) 12 Claims
OG exemplary drawing
 
1. A hydraulic jack comprising:
a base unit with a flat lower surface configured to sit on a floor;
a lift cylinder comprising a proximal end and a distal end, the proximal end being rigidly connected to the base unit;
a ram included as part of the lift cylinder, at least a portion of the ram being configured to fit within the lift cylinder and slide back and forth in and out of the distal end of the lift cylinder;
a handle rotatably attached to the base unit at a jack handle rotation point;
a hydraulic fluid reservoir connected to the base unit and containing hydraulic fluid;
a primary hydraulic pump in fluidic communication with the hydraulic fluid reservoir, and being in fluidic communication with the lift cylinder;
a primary piston rotatably attached to the handle at a piston rotation point and being configured to slidably fit within the primary hydraulic pump;
an auxiliary hydraulic pump in fluidic communication with the hydraulic fluid reservoir, and being in fluidic communication with the lift cylinder; and
an auxiliary piston configured to come in contact with the handle and slidably fit within the auxiliary hydraulic pump;
wherein the auxiliary piston comes into contact with the handle at a point further from the jack handle rotation point than a distance between the piston rotation point and the jack handle rotation point;
wherein the auxiliary hydraulic pump causes the hydraulic fluid to be pumped to the lift cylinder at load weights of less than a load-condition shift weight for the hydraulic jack; and
wherein the auxiliary hydraulic pump does not pump the hydraulic fluid to the lift cylinder upon the load weights being greater than the load-condition shift weight for the hydraulic jack.