GB2121871A

GB2121871A - A motor system of door closer

Info

Publication number: GB2121871A
Application number: GB08308584A
Authority: GB
Inventors: Duk Dan Heung
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-03-30
Filing date: 1983-03-29
Publication date: 1984-01-04
Also published as: GB8308584D0; DE3311657A1

Abstract

A motor system of door closer, having a cam shaft, a pair of spring- loaded followers, all being housed in a casing with an interlock pin of said cam shaft drawn out of said casing, said cam shaft positioned rotatably in the centre and said pair of followers aligned on the sides thereof reciprocating back and forth, said cam shaft having a pair of oval column cams formed thereon having spherical faces, said followers having double arc faces on the front faces thereof respectively, said oval column cams of said cam shaft in its rotation clockwisely and counter-clockwisely slides along the arc line of said double arc faces of said spring-loaded followers, thereby sliding the right angle pressure. Also having a grease inlet port formed on an upper disc of said cam shaft, in communicating relation with an opening formed therebetween said oval column cams, having an "O" ring seated in a recess formed around said grease port.

Description

SPECIFICATION A motor system of door closer 1. Field of invention The present invention relates generally to door closers, more particularly to a mechanical system that imparts a driving power in returning swinging doors.

2. Description of the prior art Conventionally all the door closers are based on the rack and pinion drive mechanism of gear type wherein tha rack teeth and pinion teeth intermesh in which an undue wear is critical.

While in the follower closers of conventional type, the biasedly positioned cam shaft is pressed by a tremendous power of the one-side follower loaded with a large, strong spring and the onesided pressing causes a bias pressure on the cam shaft and result in a critical wear and unsmooth operation of the mechanism.

Summary of the invention Advantageous objects could well be accomplished by the present invention which embodies among its features that an interposed cam shaft is pressed by two spring-loaded followers aligned on the sides of the cam shaft, thereby causing none of bias pressure, bringing about a smooth operation thereof and almost none of wear, and in addition a pair of oval column cams abut the smooth arc lines of arcfaced followers, bringing about even smoother operation of them all and even speed of rotation of the cam.

The prime object of the present invention is to provide a door closer mechanism in which none of bias pressure is worked on the cam shaft, resulting in an extremely minimized wear, if any, a smooth operation of the mechanism and door alike in opening and returning of the door.

Another object of the invention is to provide a door closer mechanism capable of holding door opened at 90 and 1 80 degrees without any fusible devices shown.

Brief description of drawings Other objects and features of the present invention will be more apparent to those skilled in the art from the following disclosure taken in connection with the accompanying drawings, wherein like components throughout the figures thereof are indicated by like numerals, and wherein, Fig. 1 is a facial longitudinal sectional view of the mechanical structure of a door closer in accordance with the present invention; Fig. 2 is a side view of the cam shaft, being singled out, one of the essential components of the invention; Fig. 3 is a fragmentary plane sectional view of the structure shown in Fig. 1, cut along the line A-A, illustrating a sequence when a door is closed; Fig. 4 is a plane sectional view of the same shown in Fig. 3, illustrating a sequence when the door is opened at 45 degrees;; Fig. 5 is a plane sectional view of the same shown in Figs. 3 and 4 illustrating a sequence when the door is held open at 1 80 degrees; Fig. 6 is a plane sectional view of a counter structure shown for the purpose of comparison with Fig. 4, illustrating a flat face cam and flat face followers.

Description of the preferred embodiment A cam shaft 10 is rotatably inserted in the centre of an interior hollow 41 of a casing 40, having an interlock pin 11 being exposed outside pf said casing 40, which interlocks with a correlative recess or bore formed on an arm of a door closer (not shown), further having an upper disc 12 and a lower disc 13.

Between said upper disc 12 and lower disc 13 a pair of oval column cams 1 4A and 1 4B is - formed and each of said cams having oval cross section and a spherical face 1 5 on both sides and further having an opening 1 6 formed between said cams 1 4A and 14B.

Being inserted in said interior hollow 41 of said casing 50 and confined between the parallel walls of said casing 40 so as to be capable of reciprocating back and forth, a pair of followers 20A and 20B is aligned on the sides of said oval column cams 1 4A and 1 4B of said cam shaft 10, each of said followers 20A and 20B having

double arc face 21 formed on the frontal face thereof and a centre spear 22 formed in the centre of said face 21, and said followers 20A and 20B are spring-loaded with a backspring 23 each.

All aligned in said interior hollow 41 of said casing 40, said double arc faces 21,21 of said spring-loaded followers 20A, 20B embracingly press said interposed oval column cams 1 4A, 1 4B of said cam shaft 10 in a sandwich manner.

On said upper disc 12 of said cam shaft 10, a grease inlet port 30 is formed in communicating relation with said opening 1 6 formed between said column cams 1 4A and 14B, and a ring recess 31 is formed around said port 30 and an "0" ring 32 of resilient material such as rubber is placed into said recess 31.

Numerals 42 indicates a lid for said casing 40, 50 flat face cam and 51 flat face followers, respectively.

Referring to Fig. 1 of the drawing, being inserted through the centre bore formed on the bottom of said casing 40, said cam shaft 10 rotates centrically, of which end is being said interlock pin 11 which fits in interlocked relation into a correlative recess or bore formed on an arm of a door closer (not shown), while said followers 20A, 20B, confronting with each other with said cam shaft 10 interposed therebetween, moves back and forth in opposite direction with each other as controlled by said oval column cams 14A, l4Bofsaidshaft 10.

Referring now to said Fig. 3 representing a plane sectional view of Fig. 1, said column cams I 4A, 1 4B are held static, vertically as shown in the drawing, by the centreward pressing of said spring-loaded followers 20A, 20B, and this position corresponds with the closed position of a door (not shown).

Onto Fig. 4,now the door is opened at 45 degrees, causing a clockwise rotation of said cam shaft 10, upon which time said followers 20A, 20B are pushed backwardly in opposite direction one another by the rotation of said cams 14A, 14B of said shaft 10.

Upon being released, with said back-springs 23, 23 being contracted, said followers 20A, 20B advance centrewardly, causing a back-rotation of said column cams 1 4A, 1 4B as is indicated by the arrows, to the original position shown in Fig. 3, thereby returning the door to the closed position.

Now, after a further clockwise rotation, referring to Fig. 5, said column cams 1 4A, 1 4B are held static, horizontally as shown in the drawing, by the centreward vise-pressing of said centre spears 22, 22 of said followers 20A, 20B, and this position corresponds with the hold-open position of the door at 90 degrees, and from the position on said cams 1 4A, 1 4B could either be slipped further clockwisely toward the position of hold-open at 180 degrees or counter-clockwisely backward the original position of vertically held, closed position, that is, as shown in Fig. 3.

It should be noted that the characteristics of being held static of said cams 1 4A, 1 4B represents the capability of holding door opened at 90 or 180 degrees and that being capable of rotating either clockwisely or counter-clockwiseiy it could readily be applied onto any door, regardless handling of right or left, non-handed, that is, as one single interlock pin 11 implies in Figs. 1 and 2.

In rotation, referring back to Fig. 4, said spherical faces 1 5, 1 5 of said column cams 1 4A, 1 4B substantially slides along the arc line of said double arc faces 21, 21 of said followers 20A, 20B in closely abutting relation so as to avoid right angle pressure, thereby preventing and minimizing undue friction and war and further resulting in smoother performance and even speed of rotation.

And as are clearly seen throughout the drawings, since said column cams 1 4A, 1 4B are pressed centrewardly by said followers 20A, 20B of equal spring force, there can never be any bias pressure possible, resulting in strong torsional force and even smoother operation without any of the usual bearing members.

In contrast, referring now to Fig. 6, wherein a flat face cam 50 meets with a flat face followers 51, 51, the friction and wear on the both party are critical and said cam 50 rotates abruptly in its back-rotation, meaning uneven speed of operation, unfit for an optimum performance in operation of door.

Now referring back to Fig. 1 , fed into said inlet port 30 formed on said upper disc 12 of said cam shaft 10, grease flows down into said opening 16, clearly seen in Fig. 2, where said column cams 1 4A, 1 4B and said centre spears 22, 22 of said followers 20A, 20B converge face to face as is shown in Fig. 3, and it is further spread over said column cams 14A, 14B and said double arc faces 21, 21 of said followers 20A, 20B as said cams 1 4A, 1 4B travel clockwisely and counterclockwisely in its rotation, as is partly shown in Fig. 4.

Said "0" ring 32 seated in said recess 31 formed around said grease port 30, upon being pressed by said lid 42 for said casing 40, blocks any possible leakage of grease therefrom said port 30.

From the foregoing, it would be apparent that the motor system of door closer in accordance with the present invention excels in the manner of excluding the usual bias pressure and undue wear prevailing in the conventional door closers, and in the manner of bringing about a smoother performance in operation of doors and a convenient feature of being held open at 90 and 180 degrees, not speaking of that of being nonhanded.

Claims

1. A motor system of door closer, having a cam shaft, a pair of spring-loaded followers, all being housed in a casing with an interlock pin of said cam shaft drawn out of said casing, said cam shaft positioned rotatably in the centre and said followers aligned on the sides of said cam shaft reciprocating back and forth, said cam shaft having a pair of oval column cams formed between an upper and a lower disc of said cam shaft, each column cam having an oval crosssection, also having an opening defined between said column cams, said followers having double arc faces formed on the frontal faces thereof and a centre spear formed in the centre of said double arc faces respectively, said column cams of said cam shaft in its rotation clockwisely and counterclockwisely slide along the arc lines of said double arc faces of said followers.

2. A motor system of door closer according to Claim 1, having a grease inlet port formed on said upper disc of said cam shaft, in communicating relation with said opening defined between said column cams, also having an "0" ring seated in a recess formed around said grease port.