NZ248391A - Automatic, hydraulically damped, spring actuated door closing unit - Google Patents

Description

• 24 $39 1 Patents Form # 5 Priority Date(s): I?-.'.? Complete Specification Filed: ria«?fi: Publication Date: H.QY. P.O. Journal, No: ..... rfS\ ,"t2 AUG I993^| I NEW ZEAT.ANI) \ / j • f \t V- ' } Patents Act 1953 ■ ' y COMPLETE SPECIFICATION Improved Door Closer We, Ogden Industries Pty Ltd, an Australian company, of Edward Street, Huntingdale, Melbourne, Victoria 3166, Australia, do hereby declare the invention for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: The following page is numbered "la" PF05.JWP FEE CODE-1050 24 8 3 ABSTRACT The invention is concerned with a door closer of the hydraulic kind in which a drive piston is slidable axially along a bore of the closer body, and the bore is filled with oil in order to dampen movement of the piston in either direction. The drive piston is connected to a door or other structure through a rotatable spindle and associated linkage system so that the closer can influence, and be influenced by, the position of the door. A spring urges the drive piston to move in a door closing direction, and oil must be transferred from one side of the piston to another in order for that movement to occur. Such transfer is retarded by delay means which is located within a wall of the closer which surrounds the bore of the closer body. The delay means includes a piston having an axially extending and radially stepped stem which projects into a bleed passage through which oil must pass in order for the piston to move in the door closing direction, and the rate of flow through that passage is dependent upon whether a large or small section of the stem is located within the passage. The delay piston moves in response to oil pressure to remove the large section of the stem from the bleed passage and thereby allow faster movement of the drive piston in the door closing direction.

The following page is numbered "lb" KH - la - 2 ^8 3 This invention relates to mechanisms for automatically closing a door or other member which is movable between open and closed positions. As the principal use of such mechanisms is in respect of doors, it will be convenient to hereinafter describe the invention with particular reference to door closers.

A well known form of door closer imposes its driving force on an associated door through a spindle rotatably mounted on the closer body. The spindle is caused to rotate in a door closing direction by a piston which is slidably located within the closer body and is driven by a mechanical spring. Movement of the piston in that direction is restrained by a quantity of oil within the closer body and which must be transferred from one location to another in order for the piston to complete its travel in the door closing direction. Valve means operates to control that transfer of oil.

It is known for closers of the foregoing kind to have a delay facility which comes into operation when the associated door is released from whatever force is holding it in the open position. The delay facility operates to provide a pause between the aforementioned release and the time at which the door is placed under the full effect of the closing influence of the closer. Such delay facilities are generally of complicated and expensive form. By way of example, Australian patent 495767 discloses a door closer having a delay facility provided in a complicated valve block which is detachably connected to the main body of the closer. That prior arrangement requires very careful manufacture in order to result in a facility which operates satisfactorily.

An object of the present invention is to provide a closer for doors and other movable members, which is of relatively simple construction and which is effective in operation. It is a particular object of the invention to provide such a closer having an improved delay facility.

In accordance with the present invention, the^ provided a door closer including, a body, a cyl] 7 \ / 21 JUL KH - lb- 2 4 8 3,9 f bore within said body, a drive piston slidable axially within said bore, biasing means urging said piston to move axially in one direction within said bore, drive means connected to said piston so as to be operable to move said piston axially within said bore in a direction opposite to said one direction and being responsive to movement of said piston in said one direction to produce a driving influence for means external of said body, first and second fluid chambers formed within said body and being separated by a head portion of said piston such that the size of each said chamber varies according to the axial position of said piston, said first chamber being positioned so that it decreases in size as said piston moves in said one direction, passage means through which fluid is transferred from said second chamber to said first chamber during movement of said piston in said opposite direction, transfer means through which fluid is transferred from said first chamber to said second chamber so as to permit movement of said piston in said one direction, and delay means forming part of said transfer means and which is operative to permit limited transfer of fluid through said transfer means, wherein said delay means is located within said body and is arranged so as to be operative during a first part of the movement of said piston in said one direction from a door open position towards a door closed position, and the rate at which fluid can flow through said transfer means increases when said delay means ceases to be operative.

It is a particular feature of one form of the invention that the delay facility can be incorporated in a closer body having standard valves for closing and latching speed control. That is an improvement over prior arrangements which generally required special speed control valves if a delay facility was to be incorporated in the closer.

Embodiments of the invention are described in detail in the following passages of the specification which refer to the accompanying drawings. The drawings, however, are merely illustrative of how the invention might be put into KH 248391 • A effect, so that the specific form and arrangement of the various features as shown is not to be understood as limiting on the invention.

In the drawings: Figure 1 is an end view of a closer incorporating an embodiment of the invention.

Figure 2 is a side elevational view of the closer shown in Figure 1, which is partially sectioned, and the section is taken along line II-II of Figure 1.

Figure 3-. is an enlarged view of the sectioned part of Figure 2.

Figure 4 is an enlarged cross-sectional view taken along line IV-IV of Figure 2.

Figure 5 is a view similar to Figure 4 but showing the closer piston moving in response to opening movement of an associated door.

Figure 6 is a view similar to Figure 5 but showing the closer piston commencing movement towards the door closed position.

Figure 7 is a sectional view taken along line VII-VII of Figure 4.

Figure 8 is a view similar to Figure 7 but showing the condition of the delay facility corresponding to the condition of the closer shown in Figure 6.

Figure 9 is a view similar to Figure 8 but showing the delay facility in its inoperative condition.

Figure 10 is a view similar to Figure 6 but showing the closer in a more advanced stage of the movement towards the door closed position.

Figure 11 is a view similar to Figure 9 but showing the condition of the delay facility corresponding to the condition of the closer shown in Figure 10.

Figure 12 is a cross-sectional view of an alternative form of a piston for use in the delay facility.

The door closer shown in the drawings is of a typical form having a body 1 which in use is normally secured to the door which the closer is to control, although it could be secured to a wall or frame on whieh.-.

^ £ N r - the door is supported. An end portion 2 of a spindle 3 ./,y of, - ^ or-rv . m ! KH 3 248}( extending laterally through the body 1 is, in use, connected to one end of a linkage system of a known kind which has its other end connected to the frame or wall in respect of which the door moves. The spindle 3 forms part of drive means which responds to movement of the linkage system or imparts a driving force to that system, according to the condition of the closer.

As best seen in Figure 4, the body 1 contains a cylindrical bore 4 and a drive piston 5 is slidably located within that bore. The spindle 3 and the piston 5 are interconnected through a pinion 6 provided on the spindle 3 and a cooperable rack 7 provided on the piston 5. The arrangement is such that the piston 5 is moved axially in response to rotation of the spindle 3, or the spindle 3 rotates in response to axial movement of the piston 5. Figure 4 shows the piston 5 in the position adopted when the associated door is closed. Biasing means in the form of a coil compression spring 8 urges the piston 5 to move to the right of Figure 4. When the associated door is opened, the spindle 3 is caused to rotate in a direction such that it influences the piston 5 to move to the left of Figure 4 and thereby compress the spring 8. The spring 8 is thus conditioned to impose a closing force on the piston 5.

The space formed by the bore 4 is filled with a quantity of oil, and a valve system functions to enable transfer of oil from one end of the piston 5 as that piston is moved axially through the bore. The valve system is arranged to limit the rate of that transfer when the piston 5 is moving from a door opened position towards a door closed position, and that is for the purpose of controlling the speed at which the associated door is closed.

Closers constructed in the foregoing manner are known, as is their manner of operation.

In the particular construction shown in the drawings, the piston 5 has two head portions 9 and 10 which are interconnected by the rack 7. Each head portion 9 and 10 engages the surface of the bore 4 in a fluid type KH - 4 24839 1 manner, whereas clearance exists between that surface and the rack 7. The fluid space formed by the bore 4 is divided into two chambers 11 and 12 by the piston 5, and the size of each chamber 11 and 12 varies according to the axial position of the piston 5 within the bore 4. In the particular arrangement shown, a land 13 of relatively short axial length is formed at the terminal end of the piston head portion 10, and that land 13 forms the separation between the two chambers 11 and 12.

Means is provided whereby fluid can be transferred between the two chambers 11 and 12 and thereby permit axial movement of the piston 5 along the bore 4. Preferably, that means has two operative parts, one of which is operative when the piston 5 is moving in one direction, and the other is operative when the piston 5 is moving in the opposite direction.

In the construction shown in the drawings, passage means is provided in the piston 5 to permit transfer of fluid from the chamber 12 to the chamber 11, and transfer means is provided in the body 1 to permit fluid to transfer from the chamber 11 to the chamber 12. The passage means of the particular construction shown includes a transfer passage 14 formed through the piston head portion 9, and a similar passage 15 which is formed through the piston head portion 10. A one way valve 16 is located in the passage 15 and operates to permit fluid flow through the passage 15 towards the right or front end of the piston 5 when the piston 5 is moving to the left. The valve 16 prevents flow through the passage 15 when the piston 5 is moving in the opposite direction.

The valve 16 may be of any suitable construction. In the arrangement shown, the valve 16 has a stem 17 which is slidably mounted in the passage 15, and an enlarged head 18 which is engageable with a tape::ed valve seat 19 provided on the head portion 10 (Figure 5). A resilient O-ring 20 may be attached to the head 18 to provide substantially fluid tight engagement with the seat 19.

A delay facility 21 (Figures 1 and 2) is provided in the closer body 1, and a preferred location for that KH -3, f' -i facility is shown in Figure 2. The delay facility 21 is located within a transfer passage system which forms the aforementioned transfer means and through which oil is transferred from the chamber 11 to the chamber 12. That transfer occurs when the piston 5 is travelling to the right of Figure 4. The delay facility 21 is operative to delay or substantially hinder that transfer for a period of time immediately following release or removal of whatever force or obstacle operated to prevent closing movement of the associated door. In the particular arrangement shown, the facility 21 achieves that function by means of a delay piston 22 which is movable between an operative position (Figure 8) and an inoperative position (Figure 9). When the piston 22 is in the operative position, and other positions adjacent to that operative position, it functions to substantially hinder transfer of fluid out of the chamber 11 at the front of the piston 5. Movement of the piston 5 to the right is thereby prevented or hindered.

The delay piston 22 moves towards the inoperative position in response to fluid pressure generated in the chamber 11, and that movement is controlled by a pressure responsive valve 23. Movement controlled bleed means operates to control operation of the valve 23, and it will do that regardless of the position of the piston 5 at which it commences its movement, or tendancy to move, to reduce the volume of the chamber 11.

In the particular construction shown, the transfer passage system includes a primary passage 24 which extends generally in the longitudinal direction of the closer body 1 and is located in a wall 25 of that body. Two branch passages 26 and 27 connect the primary passage 24 with the bore 4, and the passages 26 and 27 connect with the primary passage 24 at locations spaced apart in the axial direction of the bore 4. A further branch passage 28 connects the primary passage 24 with a bleed passage 29 which is controlled by the delay piston 22 and which forms part of the aforementioned bleed means. The bleed pasjjj 29 communicates with the bore 4 through KH - 6 - v y2'JUL 1994 ' 2 4 8 3 n i hereinafter described. It will be apparent that the particular arrangement of passages may be varied to suit requirements.

The delay piston 22 is slidably located within a bore 30 which connects with the bleed passage 29, and an axial stem 31 connected to the piston 22 extends into the bleed passage 29 to restrict the flow of fluid through that passage. The stem 31 forms part of the aforementioned bleed means, and is preferably stepped so as to have an axially outer portion 32 of relatively small cross-sectional size and an axially inner portion 33 of relatively large cross-sectional size. The inner and outer portions 33 and 32 of the stem 31 form first and second restrictions respectively of the delay facility. That arrangement of the stem 31 is for the purpose of achieving sequential slow and fast bleed as hereinafter described, but other means may be adopted to achieve the same result.

A coil compression biasing spring 34 acts against the piston 21 to normally urge it into the operative position, but other biasing means could be adopted for that purpose.

Any suitable pressure responsive valve may be associated with the delay piston 21. In the construction shown, that valve includes a ball 35 located within a chamber 36 formed in one end of the piston 21. A passage 37 provides connection between the chamber 3 6 and the space 38 between the piston 21 and the bleed passage 29. That connection is closed or opened according to whether the ball 35 engages a seat 39 at the inner end of the chamber 36. Any suitable stop 40 may be provided to retain the ball 35 within the chamber 36.

An outlet 41 connects the space 38 with a cavity 42 communicating with the bore 4. It is preferred that the cavity 42 is located so that it is not closed by the head portion 10 of the piston 5 when the closer is in a door open position (Figure 6).

It is preferred that means be provided to enable adjustment of the operative position of the delay piston KH 24 8? n 21. In the construction shown, that adjustment means includes a member 43 which is positioned to be engaged by the terminal end of the stem 31 and has an external screw thread cooperatively engaging with an internal thread of the bors 44 within which it is located. Rotation of the member 43 relative to the closer body 1 therefore alters the axial position of the member 43 and consequently alters the operative position of the delay piston 21.

Hydraulic closers of the kind described generally have adjustable valves for controlling the closing and latching speeds respectively of an associated door. Such valves are preferably provided in a closer according to the invention, and they may take any appropriate form. In the arrangement shown, the valve member 45 forms part of the closing speed valve, and the valve member 46 forms part of the latching speed valve. It is preferred, as shown, that the valve member 45 controls the rate of flow through the outlet 41 and the valve member 46 controls the rate of flow through the primary passage 24. Other arrangements are clearly possible.

Each of the valve members 45 and 4 6 has a tapered end portion 47 and 48 respectively which cooperates with an orifice 49 and 50 respectively. Each valve member 45 and 46 can be adjusted so that its axial position relative to the respective orifice 49 and 50 can be changed, and in that way the clearance between its respective end portion and the associated orifice is changed. The size of that clearance will determine the rate at which fluid can flow through the orifice controlled by the respective valve member 45 and 46. It will be apparent that the speed control valves could be constructed in other ways to achieve the same result.

Operation of the particular closer shown in the drawings is as follows.

When the closer piston 5 is caused to move from the door closed position (Figure 4) towards a door open position, oil is transferred from chamber 12 at the rear of the piston head 10 to enter the chamber 11 at the front of the piston 5. That transfer is effected through the KH 24 8 ~ n passages 14 and 15 in the piston 5, and the valve 16 opens to permit flow through the passage 15 as shown in Figure 5. In that regard, the valve 16 opens in response to a pressure differential generated between the left and right hand ends of the passage 15 by movement of the piston 5 to the left.

After release or removal of the force or obstacle holding the associated door in the open position, the spring 8 tends to push the piston 5 to the right as shown in Figure 6. Under those circumstances, the valve 16 closes due to the relatively high pressure generated in the chamber 11 at the front of the piston 5. Transfer of oil from the front of the piston 5 through the passage 15 is thereby prevented.

Oil then tends to escape from the chamber 11 through the branch passages 26 and 27 which are in communication with both the chamber 11 and the primary passage 24, as shown in Figure 6. Pressurized oil within the primary passage 24 attempts to escape through the branch passage 28 and the connected bleed passage 29.

At the commencement of the pressurization of oil within the transfer passage system, the delay piston 22 is at its operative position as shown in Figure 7. In that position, the stem 31 extends completely through the bleed passage 29, and the large inner portion 33 of the stem 31 is fully contained in the passage 29.

Only a small clearance as is necessary to permit sliding movement of the stem 31, exists between the stem portion 33 and the surrounding surface of the passage 29. Bleed through the passage 29 to the space 38 is thus prevented while the stem portion 33 is in the passage 29. The clearance around the stem portion 32 is somewhat larger. Pressure acting on the end of the stem portion 33 will cause the delay piston 22 to move to the left against the action of the spring 34 as shown in Figure 8. As a consequence of that movement, negative pressure is created in the chamber 38 and the ball valve 23 closes. Oil which is trapped to the left of the valve 23 is able to transfer through the outlet 41 to the bore 4 by way of the cavity KH 24 830 42.

There is restricted movement of the piston 5 to the right until the delay piston 22 reaches the inoperative position as shown in Figure 9, at which time the stem portion 33 is completely removed from the bleed passage 29. Oil is then able to flow through the passage 29 into the space 38 and a positive pressure condition is created in that space. Because of that positive pressure, the delay piston 22 will be moved rapidly to the left until further movement is prevented by engagement with a stop shoulder. Because of the relatively free flow of oil through the passage 29 into the space 38 pressure tends to build up within that space and causes the valve 23 to open as shown in Figure 9. As a result, there is relatively free flow of oil through the outlet 41 to the bore 4, and movement of the piston 5 to the right is able to occur at a speed controlled by the setting of the valve member 47.

When the land 13 of the piston head portion 10 moves forward beyond the entrance to the branch passage 27 as shown in Figure 10, transfer of oil is no longer restricted to the bleed passage 29. Oil can then escape from the primary passage 24 by way of the branch passage 27 into the section of the chamber 12 behind the piston head portion 10. Movement of the piston 5 to the right then occurs at a faster speed, as controlled by the setting of the valve member 46.

The consequent relief of pressure within the space 38 of the delay facility 21 allows the spring 34 to push the delay piston 22 back towards the operative position, as shown in Figure 11. The delay facility 21 is thereby automatically reset for response to opening movement of the associated door. .

It will be apparent from the foregoing description that the delay facility is of relatively simple form and is effective in operation. The delay time is simply changed by adjusting the position of the member 41 and thereby adjusting the operative position of the piston 19.

Figure 12 shows an alternative form of piston 22 for use in the delay facility 21, in which the head 51 of the KH © piston is a resilient cup-shaped member.

Various alterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the scope of the invention as defined by the appended claims. 1 '-1i7 KH • ' 2 4 8 ? o

Claims (13)

WHAT WE CLAIM IS:

1. A door closer including, a body, a cylindrical bore within said body, a drive piston slidable axially within said bore, biasing means urging said piston to move axially in one direction within said bore, drive means connected to said piston so as to be operable to move said piston axially within said bore in a direction opposite to said one direction and being responsive to movement of said piston in said one direction to produce a driving influence for means external of said body, first and second fluid chambers formed within said body and being separated by a head portion of said piston such that the size of each said chamber varies according to the axial position of said piston, said first chamber being positioned so that it decreases in size as said piston moves in said one direction, passage means through which fluid is transferred from said second chamber to said first chamber during movement of said piston in said opposite direction, transfer means through which fluid is transferred from said first chamber to said second chamber so as to permit movement of said piston in said one direction, and delay means forming part of said transfer means and which is operative to permit limited transfer of fluid through said transfer means, wherein said delay means is located within a wall of said body which surrounds said bore and is arranged so as to be operative during a first part of the movement of said piston in said one direction from a door open position towards a door closed position, and the rate at which fluid can flow through said transfer means increases when said delay means ceases to be operative.

2. A door closer according to claim 1, wherein said passage means is formed in said piston.

3. A door closer according to claim 1 or 2, wherein said delay means includes a bleed passage which is connected to said first chamber, a first restriction which limits flow of fluid through said bleed passage, a second restriction which allows greater flow through said bleed passage than does said first restriction, and means KH - 12 - 24 839 1 responsive to pressure within said first chamber to progressively substitute said second restriction for said first restriction.

4. A door closer according to claim 3, wherein said bleed passage is formed within a wall of said body, and said pressure responsive means is a delay piston mounted for movement in the axial direction of said bleed passage and which effects said substitution as a consequence of such movement.

5. A door closer according to claim 4, wherein a stem connected to or formed integral with said delay piston extends axially therefrom and projects into said bleed passage, said first and second restrictions are formed by respective longitudinally extending parts of said stem, and said first restriction part is located between said piston and said second restriction part.

6. A door closer according to any preceding claim, wherein a one way valve is provided within said transfer means so as to prevent transfer of fluid therethrough from said second chamber to said first chamber.

7. A door closer according to claim 6, wherein the one-way valve of said transfer means is provided within said delay means.

8. A door closer according to claim 6 or 7 when appended to either one of claims 5 and 6, wherein said one-way valve of the transfer means is provided within said delay piston.

9. A door closer according to any preceding claim, wherein said transfer means includes a closing speed valve which is located between said delay means and said second chamber, and said closing speed valve is adjustable so as to enable variation of the rate at which fluid can flow therethrough and thereby transfer from said delay means to said second chamber.

10. A door closer according to any preceding claim, wherein said transfer means includes a latching speed valve through which fluid is transferred to said second chamber when said first part of the piston movement has been completed and said delay means ceases to be KH - 13 - 248391 operative, and said latching speed valve is adjustable so as to enable variation of the rate at which fluid can flow therethrough in transferring from said first chamber to said second chamber.

11. A door closer according to any precedng claim, wherein a one way valve is provided within said passage means so as to prevent transfer of fluid through said passage means from said first chamber to said second chamber.

12. A door closer according to any preceding claim, wherein said delay means is adjustable to permit variation of the time period during which said delay means remains operative in any particular circumstance.

13. A door closer substantially as herein particularly described with reference to any one of the embodiments shown in the accompanying drawings. James W Piper & Co Attorneys For: Ogden Industries Pty Ltd 2501k r16 SEP 1994 V KH 14 /