US3467982A - Hydraulically damped actuator for self-closing doors - Google Patents

Description

Sept. 23, 1969 G. PRACHT 3,467,982

HYDRAULICALLY DAMPED ACTUATOR FOR SELF-CLOSING DOORS Filed March 10. 1967 2 Sheets-She et 1 Gain/er PRAC/lf Sept. 23, 1969 PRACHT 3,467,982

HYDRAULICALLY DAMPED ACTUATOR FOR SELF-CLOSING DOORS Filed March 10, 1967 2 Sheets-Sheet 2 V EN T 0R Gdmer Pram/77 United States Patent Int. Cl. 136st 3/06 US. Cl. 16-55 3 Claims ABSTRACT OF THE DISCLOSURE This invention provides a hydraulically damped actuator for self-closing doors. The actuator includes a bearing means supporting' a rotatable shaft which projects from a housing. A spring encircles the end of the shaft inside the housing to effect the closing of a door. A damper means is located inside the said housing and includes a reciprocally movable piston located in a cylinder which is disposed perpendicularly to the shaft axis. One end of the connecting rod is attached to the piston while the other end of the connecting rod has a large open circular end slidably mounted over an eccentric member. A bearing means is provided to mount the eccentric member independently of the shaft. A door-closing arm is coupled to the eccentric member for effectively utilizing the actuator.

BACKGROUND OF THE INVENTION In hydraulically damped actuators for self-closing doors of the specified kind the piston of the damper is operated by the shaft, so that the eccentric which operates the connecting rod must be mounted on the bottom end of the shaft which projects from the shaft bearing. Since the shaft is subjected to considerable loads and must therefore be mounted in a bearing of relatively great length, the described form of construction of a hydraulically damped actuator for self-closing doors necessarily requires a housing of inconveniently great height.

SUMMARY OF THE INVENTION It is therefore the object of the present invention to overcome this drawback by providing a hydraulically damped actuator for self-closing doors of the afore-described type which, compared with conventional actuators, is of much reduced height and which is also structurally much simpler.

For achieving this object the present invention consists in mounting the eccentric independently of the shaft and in directly coupling the same to the door-closing arm, the door-closing spring embracing the end of the shaft inside the actuator housing directly below the shaft bearing.

The proposed separation of the eccentric from the shaft permits the eccentric to be located highed up in the housing, thereby fundamentally altering the disposition of the components in the available space in favor of a more compact form of construction of the actuator housing. The proposed removal of the eccentric into a higher position makes the free projecting end of the shaft inside the housing available for exclusive cooperation with the doorclosing spring, and consequently the height of the housing can be reduced. Moreover, the direct connection of the door-closing spring to the shaft eliminates the necessity of providing an entraining and pretensioning bush and of coupling the latter to the door-closing arm. The proposed arrangement thus structurally substantially simplifies the self-closing door actuator. Finally, the proposed arrangement permits the door-closing spring to be readily exchanged through the open bottom of the actuator housing without requiring the door-closing arm to be first detached from the shaft as was hitherto necessary.

According to an important feature of the invention the closing arm and the eccentric are coupled by a hub formed on the eccentric and adapted on its end projecting from the housing to receive the fitting head of the closing arm in a push-on fit, whereas the coupling connection between the door-closing arm and the rotatable shaft is established by a push-in coupling member which nonrotatably engages the end of the shaft which projects from the housing as well as the fitting head of the doorclosing arm.

BRIEF DESCRIPTION OF DRAWINGS An embodiment of the invention will now be described by way of example and with reference to the accompanying drawing, in which:

FIG. 1 is a longitudinal section through a self-closing door actuator according to the invention;

FIG. 2 is a section taken on the line II-II of FIG. 1;

FIG. 3 is a view of the eccentric and its hub;

FIG. 4 is a section taken on line IV-IV of FIG. 1, and

FIG. 5 is a sectional bottom view of the actuator as shown in FIG. 1.

DESCRIPTION OF SPECIFIC EMBODIMENT With reference now to the drawing, 1 is the actuator housing, 2 is the door-closing shaft which works in the actuator housing 1 in a journal bearing 3 formed by a steel bush, 4 is the door-closing arm, 5 is the closing spring and 6 is a preferably steel cylinder liner firmly fitted into the actuator housing 1 and together with a piston 7 forming the damping device. The outer end of the cylinder liner 6 is sealed by a screw plug 8. 9 is a cylinder core which axially traverses the piston 7 and which is secured therein by threads engaging the piston interior. The projecting threaded end of the core 9 carries a counternut 10 which is tightened against the end face of the piston 7. 11 is an eccentric mounted on the journal bearing 3 and slidably supported by an intermediate platform (not numbered) inside the actuator housing. The eccentric 11 cooperates with a connecting rod 12 of which the big end embraces the eccentric, whereas the other end works on a gudgeon pin 13 mounted on the periphery of the projecting end of the core 9 of the piston 7. The eccentric 11 is formed with a collar or hub 14 which projects from the actuator housing 1 to the outside. The hub 14 has an internal shoulder which bears on the end of the journal bearing 3, whereas the end of the hub projecting from the housing 1 embraces the shaft 2. Externally, the projecting end of the hub 14 has a square cross section embraced by the correspondingly shaped fitting head 15 of the doorclosing arm 4. The shaft 2 which is encircled by a split ring 16 resting on the end of the hub 14 of the eccentric 11 is provided with a reduced section square end which passes through the fitting head 15 of the closing arm 4. 17 is -a coupling member which fits over the reduced square end of the shaft 2 for common rotation therewith and which also engages and fits into the interior of the fitting head 15 of the closing arm 4, thereby rigidly coupling together the closing arm 4 and the shaft 2 and hence the eccentric 11. The coupling member 17 is located on the reduced end of the shaft 2 by a split ring 18. 19 is an assembly opening in the actuator housing 1 closable by a screw cover 20. The bottom end of the shaft 2 projecting from the journal bearing 3 is formed with a circular enlargement 21 which is encircled by the closing spring 5 located in a spring housing 22. The spring 5 may be mounted in the actuator housing 1 in any manner known in the prior art. In this specific embodiment the inner claw end 25 of the spring 5 engages an axial slot 26 in the enlargement 21 of the shaft 2. The outer spring end 23 engages a recess 24 located in the actuator housing l-in a manner well known in the prior art. In conventional manner the actuator housing 1 is enclosed by a cow] not shown in the drawing.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respect as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description.

I claim:

1. A hydraulically damped actuator for self-closing doors comprising, in combination,

(a) a bearing means suporting a rotatable shaft which projects from a housing,

(b) means mounting a spring which encircles the end of a shaft inside the housing to effect the closing of a door,

(c) a damper means including a reciprocally movable piston located in a cylinder which is disposed perpendicularly to the shaft axis,

(d) means connecting one end of a rod to the piston,

(e) the other end of the rod having a large open, circu lar end slidably mounted over an eccentric member,

(f) bearing means mounting said eccentric member independently of the shaft,

(g) said closing spring being located below the said bearing means, and a (h) means coupling a door-closing arm to the eccentric member.

2. An actuator for self-closing doors as claimed in claim 1, wherein the closing arrnand the eccentric are coupled by a hub formed on the eccentric and adapted on its end projecting from the housing to receive the fitting head of the closing arm in a push-on fit, whereas the coupling connection between the door-closing arm and the shaft is established by a push-in coupling'rnember which engages the end of the shaft projecting from'the housing as well as the fitting head of the door-closing arm.

3. An actuator for self-closing doors as claimed in claim 1, wherein the bottom end of the shaft below the bearing has a circular enlargement embraced by the doorclosing spring.

References Cited UNITED STATES PATENTS 3,210,797 10/1965 Heinitz et a1. 16-59 BOBBY R. GAY, Primary Examiner JAMES KOHNEN, Assistant Examiner UNITED STATES PATENT OFFICE CERTIFICATE *OF CORRECTION Patent No. 3,467,982 September 25, 1969 G'u'nter Pracht It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading to the printed specification, lines 4 to 6, "assignor to C. Eisen Grossmannund Stahlwerk AG. Solingen- Wald, Germany, a firm" should read assignor to C. Grossmann Eisenund Stahlwerk AG. Solingen-Wald, Germany, a firm Signed and sealed this 10th day of November 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Commissioner of Patents Edward M. Fletcher, Jr.

Attesting Officer

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