Expansible chamber devices – With releasable stop or latch means to prevent movement of... – Engages member coaxial with and rotatable relative to...
Patent
1987-11-09
1989-08-08
Garrett, Robert E.
Expansible chamber devices
With releasable stop or latch means to prevent movement of...
Engages member coaxial with and rotatable relative to...
92 24, 92 25, 92 27, 92 21MR, 92116, 91 45, 74 2, 74529, 49280, F15B 1526, E05F 1500
Patent
active
048542237
DESCRIPTION:
BRIEF SUMMARY
The invention is directed to a pneumatic or hydraulic drive for opening and closing of doors, in which the linear motion of a double-acting piston driven by a pressure medium is converted by means of a piston rod and a helical gear box into rotational motion of a spindle.
The disadvantage in the known rotary drives of this sort is that in case of pressure loss of the working medium the double-acting piston moves downwards and the door can open. Herein there arises the danger that the door yields under a force in the sense of opening of the door and thus persons are endangered. If the leakage arises during a period when the vehicle is parked, access of unauthorized persons inside the vehicle is possible.
The invention aims at creating an arrangement, which blocks the opening motion of the door in case of pressure loss. This is achieved in the invention in that a stationarily supported blocking lever is provided which in the closed position of the door engages under spring action at a part connected with the piston, wherein said blocking lever secures the piston in its end position and is held in its open position counter to the force of another spring by means of a power cylinder acted upon by a pressure medium.
Since the blockage has to be removed in order to be able to open the door, it is provided in a refinement of the invention that the blocking lever is connected with a manually operated Bowden cable.
A particularly advantageous embodiment results if the Bowden cable emanates from a hand lever, which can actuate a three-way cock in the pressure line of the pressure medium, which in the one end position of the hand lever connects the pressure medium line with the return flow. This creates an emergency actuation arrangement.
The subject of the invention is depicted in the drawing in an embodiment form by way of an example.
FIG. 1 shows the elevation of a door drive according to the invention in vertical section,
FIGS. 2 and 3 show a cross-section, wherein in FIG. 2 the blocking lever is depicted in its effective and in FIG. 3 in its ineffective position, and
FIG. 4 shows a control circuit arrangement.
A shaft 2 is supported in a console 1, which shaft can be rotated by means of a helical gear box 3. Below the helical gear box a power cylinder 4 with a double-acting piston 5 together with inlet and outlet flow means for the pressure medium is provided. The piston rod 6 is equipped with a pair of rollers 7, guided in slots 8 of the helical gear box 3. Thus the axial motion of the double-acting piston 5 is converted into a rotary motion of the shaft 2, which embraces the pair of rollers 7 by means of axial slots.
If the end of the slots 8 is designed to be inclined with respect to the rotational axis, so that no self-locking feature exists, then one runs the danger, that in case of pressure loss the double-acting piston 5 is no longer secured in its upper position and that at least in case of a load acting upon the door no resistance can be opposed to a rotational movement of the shaft 2. In order to prevent this, an angular blocking lever 10 is pivotably supported at a console 9, which in its non-depicted blocking position grips beneath a roller 11, which is supported at the piston rod 6 coaxially with the roller pair 7. A piston rod 12 of piston 13 is linked to the blocking lever 10, said piston 13 sliding in a power cylinder 14 and being acted upon on one side by the same pressure medium as the double acting piston 5. A pressure spring 15 is inserted between the one front face of the power cylinder 14 and the pistons 13. The power cylinder 14 is pivotably supported at a console 16. The blocking lever 10 is rigidly connected by means of a shaft with the lever 10a, acted upon by a Bowden cable 17, which enables a manual pivoting of the blocking lever 10 out of its blocking position counter to the force of a spiral spring 18. The entire arrangement is covered by a casing 19.
According to FIG. 4 the power cylinder 4 is connected with a control valve 22 by means of lines 20, 21, one side of said control valv
REFERENCES:
patent: 720399 (1903-02-01), Brewer
patent: 1002596 (1911-09-01), McElroy
patent: 1098585 (1914-06-01), Mills
patent: 2932282 (1960-04-01), McKinley
patent: 4185539 (1980-01-01), Stratienko
patent: 4545149 (1985-10-01), Jentsch
patent: 4731886 (1988-03-01), Heinrich et al.
Denion Thomas
Garrett Robert E.
IFE Industrie-Einrichtungen Fertigungs-Aktiengesellschaft
LandOfFree
Pneumatic or hydraulic drive for opening and closing of doors does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Pneumatic or hydraulic drive for opening and closing of doors, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pneumatic or hydraulic drive for opening and closing of doors will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-898012