Patent ID: 11896531
Assignee: STRYKER CORPORATION
Field: Medical technology (Instruments)
Classification: CPC A  F | IPC A  F

Claim 0:
1. A patient handling apparatus comprising:
a patient support surface;
a base; and
a hydraulic circuit comprising:
a hydraulic cylinder operable to selectively raise or lower the patient support surface or the base relative to the other of the patient support surface or the base, the hydraulic cylinder having a rod, a cap end chamber, and a rod end chamber, the rod having an extension or retraction speed;
a pump; and
a fluid reservoir; and
the hydraulic circuit being operable to control the flow of hydraulic fluid between the hydraulic cylinder and the fluid reservoir, wherein the hydraulic circuit includes a bypass circuit configured to selectively open fluid communication between the hydraulic cylinder and the fluid reservoir to bypass the pump for faster evacuation of the hydraulic fluid from the hydraulic cylinder to thereby allow at least one of increased retraction speed and increased extend speed of the rod and quickly raise the base relative to the patient support surface, and wherein the hydraulic circuit includes an accumulator separate from and in fluid communication with the hydraulic cylinder and the fluid reservoir to maintain pressure of the hydraulic fluid in the hydraulic circuit,
wherein the accumulator maintains an inlet of the pump submerged in hydraulic fluid, and wherein the accumulator is pre-charged to pressurize hydraulic fluid in the accumulator and the reservoir.