Patent · US Expired

Devices for applying pressure to a closed door

US4960265A · kind A · utility

2Cited by
3References
1Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMay 11, 1988
Grant dateOct 2, 1990
Priority date
Expiry dateMay 11, 2008

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T29/53683
  • WIPO fieldMachine tools
  • WIPO sectorMechanical engineering

Abstract

A jack for opening locked or barricaded doors has a first hydraulic single acting piston and cylinder actuator mounted on a casing by which holding claws are forces into engagement with a door frame to hold the jack in place. An arm is pivotted on the casing and an end opposite the pivot forced against the door by a second hydraulic single acting piston and cylinder actuator to open the door, reaction to the opening force being transmitted to the door frame through the casing and claws. The reservoir for the hydraulic fluid is provided to the rear of the piston of the actuator. The jack is readily portable and self-contained, and does not present a significant obstacle to entry through a door which has been forced using the jack.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.