GB2462633A

GB2462633A - A roller cam follower mounted within a rotatable carrier

Info

Publication number: GB2462633A
Application number: GB0814871A
Authority: GB
Inventors: Peter Edward Brown; Arnold Taylor
Original assignee: Jebron Ltd
Current assignee: Jebron Ltd
Priority date: 2008-08-14
Filing date: 2008-08-14
Publication date: 2010-02-17
Anticipated expiration: 2028-08-14
Also published as: GB0814871D0; GB2462633B

Abstract

A roller cam follower for a door closer comprising a body member 70 having an axis and adapted to be supported in a body part of the door closer (fig.5) for movement relative thereto linearly along the axis and angularly about the axis, the body member 70 having an open first end portion from which a recess 76 extend axially into the body member to a second end portion thereof; cam follower carrier member 94 at least partially disposed within the recess of the body member and angularly moveable with the body member about the axis thereof, the support member 94 supporting a roller element 102 for rotation about an axis extending transversely of the body member at the first end portion thereof; and a bearing ball 84 interposed between oppositely axially-facing surfaces of the body member and support member within the second end portion of the body member. Free rotation of cam follower carrier member 94 within body member provides anti-torsion arrangement means such that rotation of the body member 70 caused by a helical compression spring will not necessarily cause misalignment of roller follower axis 100 and cam axis (14, fig.5). A second cam follower 136 is disclosed rotatably mounted to a support 126 wherein the roller cam follower carrier 126 is able to pivot such that roller axis 134 can be offset laterally to both sides of body member axis 180 to enable cam follower to be used on both right and left hand operated doors closers.

Description

Title: Door Closer

Description of Invention

This invention relates to a door closer.

A door closer in accordance with the invention is of the type which comprises a body which is adapted to be secured to a pivotally-opening door, the body either being mounted on a surface of the door or possibly concealed within the thickness of the door. A rotary member is supported by the body for angular movement about an axis, and the rotary member is caused to undergo such movement as the door is opened and closed. To this end, the rotary member may carry an arm whose end remote from the rotary member is provided with a slider block or the like, engaging with a track mounted on or in a transom member of a doorway relative to which the door is moveable, the slider block moving along the track as the door moves. The rotary member carries a cam whose peripheral cam surface is engaged by at least one roller cam follower moveable linearly within the body in accordance with angular movement of the rotary member, to cause displacement of at least one element for controlling the motion of the door. S...

In the embodiment of door closer described hereafter, the cam is engaged by *. 25 two roller cam followers. One of them causes displacement of a spring * element, acting on a helical compression spring, so that the spring is (increasingly) compressed as the door is opened and thereby causing the door * *5 S. S * to be biased to the closed position. The other roller cam follower, disposed on the opposite side of the axis of the rotary member from the first cam follower, causes displacement of a damping element, so as to damp the closing movement of the door by causing flow of oil between respective cylinder volumes of a damping arrangement.

A roller cam follower has a roller element which engages the cam surface, and it is important that the axis about which the roller element is rotatable relative to the cam follower remains substantially parallel to the axis of the rotary member, i.e. the axis about which the cam moves angularly. This ensures contact between the roller element and the operative surface of the cam across the full width thereof. The forces acting between the cam and follower are high, so the full-width contact minimises wear and friction. A factor to be taken into consideration in this is that when a helical spring is compressed or extended a torque is generated between the two ends thereof, about the longitudinal axis of the spring. To prevent this torque from causing misalignment between the cam follower roller element and the cam, features such as one or more guide elements for the cam follower have been adopted, to ensure the cam follower remains in a fixed orientation as it moves linearly, together with a thrust bearing arrangement interposed between the cam follower and spring. Such features are effective, but expensive to incorporate in a door closer.

it is a first object of the present invention to address this problem.

20 According to one aspect of the invention, we provide a roller cam follower for a door closer, comprising a body member having an axis and adapted to be * supported in a body part of the door closer for movement relative thereto linearly along the axis and angularly about the axis; the body member having an open first end portion from which a recess extends axially into the body member to a second end portion thereof; a support member at least partially disposed within the recess of the body member and angularly moveable within the body member about the axis of the body member, the support member supporting a roller element for rotation about an axis extending transversely of the body member at the first end portion thereof; and a bearing ball interposed between oppositely axially-facing surfaces of the body member and the support member within the second end portion of the body member.

The support member may be constrained to movement within the body member angularly about the axis of the body member and linearly along such axis.

When a roller cam follower in accordance with the invention is used to cause displacement of a spring element of a door closer, the second end portion of the body member of the cam follower can abut an end of a helical spring or spring assembly directly, without any inter-position of a thrust bearing. The disposition of a bearing ball between the facing surfaces of the body member and support member acts as an effective and low-cost thrust bearing between these two members, so the body member can move angularly about its axis under any torque applied thereto by the spring, while the support member can remain aligned with the cam so that the roller element correctly engages the surface of the cam.

20 Preferably the body member has a cylindrical external surface by which it can *. be supported in the door closer for linear movement along, and angular * movement about, its axis. There is no need for any interruption of such a cylindrical surface to accommodate, for example, a bearing pin on which the roller element is supported, so there is a large bearing surface between the body member of the cam follower and the body of the door closer within which * it is received, so wear of either or both of these components is minimised over I.....

* a long service life.

The bearing ball may be partially disposed within a recess provided inside the body member at the second end portion thereof, so that the bearing ball is constrained to lie with its centre on the axis of the body member.

A roller cam follower in accordance with the first aspect of the invention may be used to cause displacement of a damping element of a door closer, for damping the closing movement of a door. One aspect of the design of the damping characteristics of a door closer is that the closing movement of a door might require to be damped so that its movement is retarded, right up to the fully closed position. To achieve this the profile of the cam which moves the damping element through the intermediary of the cam follower must provide for significant movement of the damping element even as the cam is approaching the position it adopts when the door is fully closed. This is because, for effective control of damping, sufficient movement of the damping element must be provided to cause a reasonable flow of the damping oil through the flow-restrictor(s) causing the damping: without a sufficient flow damping will be relatively uncontrolled. This requires that the profile of the cam part controlling the damping must be relatively steep' in the vicinity of the door-closed position.

A further factor is that door closers desirably are able to work with left-handed or right-handed doors without any internal modification. The cam of the door closer is displaced in opposite directions from a starting, door-closed, position according to whether the door opens left-handedly or right-handedly and the cam must be symmetrical if the closer is to be able to damp equally for left-and right-handed doors. The requirement for a steep' cam surface profile on either side of a starting position means that the part of the cam that determines damping characteristics has a peak' or apex. With a symmetrical cam, the door-closed position will place the peak or apex of the cam nearest to the cam follower, analogous to a top-dead-centre position where angular movement of the cam produces no displacement of the cam follower. Therefore it is difficult to arrange for sufficient damping element movement near to the door-closed position to control the door in he last stage of its closing. It is the object of another aspect of the invention to address this problem.

According to a second aspect of the invention, we provide a roller cam follower for a door closer, comprising a body member having an axis and adapted to be supported in a body part of the door closer for linear movement along the axis, and supporting a roller element for rotation about an axis extending transversely of the body member axis, wherein the axis of rotation of the roller element is able to be displaced laterally relative to the body member, between respective positions on opposite sides of the axis of the body member.

With a cam follower of this type, the ability to displace the rotational axis of the roller element relative to the cam follower as a whole means that the roller element can engage the relatively-steep surface of the cam to either side of its apex when the door is in the nearly-closed position, according to whether the door opens left-handedly or right-handedly. Thereby good control of damping can be achieved, as significant axial movement of the cam follower can be provided even when the door is nearly closed.

The cam follower according to the second aspect of the invention may be a follower according to the first aspect of the invention as first set forth above, wherein the support member is able to move pivotally relative to the body member of the cam follower about the bearing ball by which it is axially supported in the body member. In the vicinity of the second end portion of the *I.

body member, the support member may be constrained radially within the body member, but at the open first end of the body member the support S.. . * member and/or the interior of the body member may be relieved to provide for lateral displacement of that end of the support member within the body member.

In this embodiment of cam follower, the support member remains able to move angularly within the body member about the axis of the latter, so that the roller element is able to self-align with the cam surface.

According to another aspect of the invention, we provide a door closer including a roller cam follower according to the first aspect of the invention.

According to yet a further aspect of the invention, we provide a door closer including a roller cam follower according to the second aspect of the invention asabovesetforth.

Preferably, and in the embodiment described hereafter, the door closer includes a first cam follower according the first aspect of the invention, for causing displacement of a spring element of the closer, and a second cam follower according to the second aspect of the invention, for causing displacement of a damping element of the closer.

The invention will now be described by way of example with reference to the accompanying drawings, of which: Figure 1 is an elevation of a door closer illustrating its disposition and manner of connection to a door.

Figure 2 is a plan view of the door closer of figure 1.

Figures 3 and 4 are vertical sections through a door closer in accordance with the invention, respectively in different operative conditions.

* 20 Figure 5 is a horizontal section through the door closer in accordance with the invention. S...

S....' Figures 6a and 6b are respective sections, in planes at right angles to one *:*::* another, through a first embodiment of roller cam follower of a door closer in * accordance with the invention. *.S

Figures 7a and 7b are respective sections through a further embodiment of *:::* roller cam follower.

Figure 8a and 8b are enlarged sections, in a different plane, of part of figures 3 and 4, respectively.

Referring firstly to figures 1 and 2, these show a door closer which comprises a body 10 which is arranged to be surface-mounted on a door, secured thereto by fixing screws as indicated at 12. Alternatively, the door closer could be arranged to be mounted within the thickness of a door, at its top edge. The door closer comprises a rotary member 14 which operates the internal components of the door closer described hereafter, and a connecting member 16 extending above the body of the closer provides for connection of one end of an arm 18 to the rotary member 14. The other end of the arm 18 is pivotably connected to a slide block 20 moveable lengthwise of a trackway 22 which is connected to the transom of a doorway relative to which the door is moveable. The configuration and mounting details of the slide block 20 and trackway 22 do not form part of the present invention, and therefore will not be described in greater detail herein.

Referring now to figures 3, 4 and 5 of the drawings, these show the internal components of the door closer, in different operative conditions. The rotary member moveable angularly about axis 14 is shown at 24; at its uppermost end it has a splined socket 26 for engagement by the connecting member 16 to which the arm 18 is attached. The rotary member 24 is supported in body of the door closer by an upper bearing assembly indicated generally at 28 and a lower bearing assembly indicated generally at 30; these are roller * 20 bearing assemblies of known type and will not therefore be described in further s.". detail. The rotary element 24 carries a cam 32 which is somewhat heart-**..

shaped in configuration, and the cam is engaged, on opposite sides of the axis *:::* 14, towards opposite ends of the body 10, by respective roller cam followers indicated generally at 34, 36 and described in greater detail hereafter.

The roller cam follower assembly 34 acts on one end of a spring assembly 38, comprising a first helical compression spring 40 within which is disposed a second helical compression spring 42, of smaller diameter. The corresponding ends of both springs 40, 42 abut the cam follower 34 and the opposite ends of the springs engage an abutment assembly indicated generally at 44. The abutment assembly 44, described in greater detail hereafter, provides for adjustment of the pre-load applied to the outer spring 40 which is the stronger of the two springs 40, 42. The pre-load applied to the spring 42 is not adjustable, so the result is that the total load exerted by the springs 40, 42 on the cam follower 34 is adjustable between pre-determined minimum and maximum values.

The cam follower 36 causes displacement of elements to damp the closing movement of a door having the door closer. The cam follower 36 abuts a hollow push-rod 50 which is connected to a damping piston 52, the push-rod 50 extending through a separator element 54 which is fixed in position in the body 10 of the door closer, being screwed into a seating 56 in the body. The piston 52 works in a damping cylinder bore 58 in the body, and beyond the piston 52 there is a closure plug 60 held in the bore 58 by a circlip 62. A helical compression spring 64 is operative between the closure plug 60 and the piston 52. The spring 64, acting on the piston 52, causes the cam follower 36 to be biased so its roller is kept in contact with the cam 32. The cam follower 36 is itself moveable lengthwise of the body 10 within a bore 66 of the body of smaller diameter than the bore 58.

* 20 Figures 3 and 5 illustrates the cam follower 36 in the position it assumes when the door is closed, while figure 4 shows the cam follower in the position it S...

assumes when the door is open. It will be apparent that its movement from the door-open position to the door-closed position causes a reduction in the volume defined between the cam follower 36 and the divider plug 54, and in the space between the piston 52 and closure plug 60, and an increase in the *... volume defined between the divider plug 54 and piston 52 by controlling the flow of oil (with which the door closer is filled) between these spaces, closing movement of the door is damped. In known manner for damping arrangements in door closers, various passages and controlling valves are provided to control such flow of oil, and to permit substantially unimpeded flow of oil in the opposite directions as the door is opened. For example, figure 5 shows that the piston 52 is provided internally with a overload valve indicated generally at 68 and a one-way ball valve indicated generally at 70, for controlling oil flow between opposite sides of the piston 52. Other passages for flow of oil, with suitable controlling valves, are provided in the body 10 but not illustrated herein.

The cam follower 34 is shown in greater detail in figures 6a and 6b. It comprises a support member 70 which is a hollow component with an outer cylindrical wall 72 which is a close sliding fit within a bearing sleeve (not shown) in a part 74 of the closer body 10. A recess with a cylindrical wall 76 extends into the body member 70 from an open end thereof, towards a closed end portion 78 of the body member 70. The central axis of the body member is indicated at 80, and centred on this axis 80 there is a recess 82 in which is received a bearing ball 84, the bearing ball 84 protruding out of the end portion 78 towards the open end of the body member. The end portion 78 of the body member has, exteriorly, an annular ledge 86 which in use is abutted by the spring 40 and a raised circular boss 88 which is abutted by the spring 42.

* 20 Within the body member 70 there is disposed a support member 90 which :::::: comprises a circular base portion 92 which has a flat end surface abutting the bearing ball 84. From the base 92, two spaced parallel limbs, 94, 96 extend to *:*::* and slightly beyond the open end of the body member 70, the limbs 94, 96 having part-cylindrical external walls in continuation of the outside diameter of the base portion 92 of the support member. These engage, for rotational movement about the axis 80, the internal wall 76 of the body member 70. The limbs 94, 96 are provided with aligned apertures adjacent their free ends, and a bearing pin 98 extends across the support member 90 being received in the apertures in its limbs 94, 96. The bearing pin 98 supports, for rotation about a transverse axis 100, a roller 102 which engages the peripheral surface of the cam 32. The roller 102 is carried on the bearing pin 98 on needle rollers visible at 104 in figure 6a. Once the support member has been fitted axially into the body member 70, the bearing pin is held captive and no additional securing means for the bearing pin is necessary.

The end portion 78 of the body member 70, and the base portion 92 of the support member, each have an aperture to enable oil to pass the cam follower.

Figure 7a and 7b show the cam follower 36 which is slightly different from the cam follower 34. This cam follower comprises a body member 110 with a recess extending into it from an open end 112 to a closed end portion with an end wall 114. The body member 110 has a cylindrical external wall 116 with, since movement of the body member 114 causes displacement of oil for damping door closing movement, has an annular sealing ring 118. The annular cylindrical wall 120 of the body member 110 is, relatively, somewhat thinner than the wall 70 of the body member of the cam follower 34. The end wall 114 carries a bearing ball 124 in a recess 122.

The body member 110 of the cam follower 36 receives a support member 126 which has a base portion 128 which is supported on the bearing ball 124 and * 20 has a maximum external diameter which fits closely within the cylindrical internal surface of waIl 120 of the body member. In the depicted sections, it S...

will be seen that the external peripheral portion of the base 128 is radiused so *:*::* that it is able to tilt from the position (depicted in figures 7a and 7b) in which the base lies perpendicular to the axis (180) of the support member 110.

As for the cam follower 34, the support member 126 of cam follower 36 has spaced limbs which extend from its base 128 to the open end of the body member 110. Such limbs (130, 132) carry a bearing pin 134 adjacent their free ends, the bearing pin supporting a roller 136 for rotation about a transverse axis 138 as shown in figure 7b, the ends of the bearing pin 134 are domed or conically tapered, and it will be noted that there is a clearance between the limbs 130, 132 and the interior of the wall 120 of the body member all around the internal periphery of the wall's open end. Hence, the support member is able to tilt within the body member of the cam follower, pivoting about the bearing ball 124 in so doing.

Figure 5 of the drawings shows the cam follower 36 in a position it will assume in use, with the support member of the cam follower tilted relative to the body member thereof. The operative condition in which the components are illustrated is that of figure 3, in which the door is closed. As above mentioned, the cam 32 is somewhat heart-shaped, and with the door closed the roller element 102 of cam follower 34, urged by springs 40, 42 to move the door to the closed position by causing the cam 32 to be moved angularly, lies in a shallow recess 140 on part of the cam's periphery. Diametrically opposite the recess 140, the cam 32 has an apex 142 on either side of which there are relatively steep parts of the cam's profile, necessary to ensure adequate movement of the cam follower 36 and hence a reasonable displacement of oil in the damping arrangement and effective damping of the door's movement, as the door approaches the closed position.

* 20 Figure 5 shows the support member 126 of the cam follower 36 tilted upwardly towards the cam 32, which is the position it assumes when opening of the door causes displacement of the cam in the clockwise direction from the figure 5 position. This corresponds to a door which opens left-handedly or right-handedly as the case may be. If the door is of opposite hand, the cam will be displaced anti-clockwise from a position close to that in which it is shown in *.*.. figure 5 as the door is opened, and in this case a small amount of such anti-clockwise displacement of the cam will move its apex 142 upwardly from the illustrated position. When a certain point is reached and the apex of the cam engages with the roller 136 at a position offset from the axis 180 of the cam follower, the support member of the cam follower will snap over until it is tilted downwardly towards the cam. Therefore, the roller 136 of the cam follower 36 is able to engage a steep part of the cam's profile as the door approaches the closed position, whether the door opens left-handedly or right-handedly.

In either of the tilted orientations of the support member of the cam follower 36, its roller 136 is able to self-align with the surface of the cam 32 to engage properly therewith.

Finally, the adjustable abutment mechanism 44 by which the pre-load applied to spring 40 can be adjusted will be described in greater detail with reference to figures 8a and 8b of the drawings. At the end of the body 10 of the door closer having the adjustment mechanism 44, the cylindrical internal bore (indicated at 150) of the body is closed by a closure member 152 of annular configuration, retained by a circlip 154. Centrally of the closure member 152 the closure member rotatably supports an adjustment screw 156 having a hexagonal socket head 158 enabling the screw to be turned by a hexagonal key. Beyond the socket 158 the adjusting screw 156 has a passage 160 closed by a plug 162 for enabling the interior of the door closer to be filled with oil. The adjustment screw 156 has a flange 164 which abuts the closure member 152 to react the forces exerted on the screw 156 by the springs 40, 42.

* .* . The screw 156 has a screw-threaded shank portion 166 engaged by a nut 168 provided in the interior of an annular abutment member 170 on which the spring 40 bears. The external surface of the abutment member 170 fits closely within the bore 150 of the closure body 10. The end of the screw 156 has a recess 172 for a locating spigot 174 of an abutment member 176 for the spring *.*** * * A collar 182 is fitted on the screw 156 and is freely moveable axially over the crests of the screw thread 166 thereon. It is retained on the screw by a circlip 184 engaging an annular groove close to the free end of the screw. A pair of guide pins 186 are fixed to the closure member 152 and extend parallel to the screw 156 to a position approximately mid-way therealong. These guide pins engage in respective guide sleeves 188 which are carried by respective pockets on opposite sides of the abutment member 170. The guide sleeves are able to be displaced out of the abutment member in the direction towards the closure member 152, until such displacement is limited by engagement of steps in the pockets 190 of the abutment member 170, by external steps on the guide sleeves. The ends of the sleeves 188 remote from the closure member 152 are able to make contact with the collar 182.

The engagement of the guide pins 186 with the guide sleeves 188 and the pockets 190 in the abutment member 170 ensure that the abutment member having the nut 168 is unable to rotate relative to the closure member 152.

Therefore, when the screw 156 is turned, the abutment member 170 is driven in either direction along the screw 156, according to the direction of turning of the latter. Thereby the preload on the spring 40 can be adjusted.

Figure 8b shows the adjustment mechanism in the position assumed by its components when the minimum pre-load is applied to the spring 40. The * 20 abutment member 170 lies against the closure member 152, while the guide pins 186 are accommodated within the guide sleeves 188 in turn received in S...

the pockets 190 of the abutment member 170. When the screw 156 is turned *:::* by a key engaged with socket 158, the nut 168 is advanced along the screw towards its free end, and the guide sleeves 188 move along the guide pins 186. The guide sleeves will contact the collar 182 and move the latter along the screw 156 until the collar abuts the circlip 184. Then, with further turning of the screw and movement of the abutment member, the guide sleeves 188 will be caused by the collar 182 to remain in position relative to the length of the screw 156, being displaced rearwardly relative to the abutment member 170. This will ensure that the guide sleeves 188 cannot become disengaged from the guide pins 186 received within the sleeves.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof. * *. * * * * ** S... * S **.. * ** * * * * **

S

S * .. * S S * SS *

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Claims

Claims 1. A roller cam follower for a door closer comprising a body member having an axis and adapted to be supported in a body part of the door closer for movement relative thereto linearly along the axis and angularly about the axis, the body member having an open first end portion from which a recess extend axially into the body member to a second end portion thereof; a support member at least partially disposed within the recess of the body member and angularly moveable with the body member about the axis thereof, the support member supporting a roller element for rotation about an axis extending transversely of the body member at the first end portion thereof; and a bearing ball interposed between oppositely axia'ly-facing surfaces of the body member and support member within the second end portion of the body member.
2. A roller cam follower according to claim 1 wherein the support member is constrained to movement within the body member angularly about the axis of the body member and linearly along such axis.

* ** 20
3. A roller cam follower according to claim 1 or claim 2 wherein the body member has a cylindrical external surface, by which it can be supported in the door closure for linear movement along, and angular movement about, its axis. * ** * S * * **
4 A roller cam follower according to any one of the preceding claims wherein the bearing ball is at least partially disposed within a recess provided *.: inside the body member at the second end portion thereof, to lie with its centre on the axis of the body member.
5. A roller cam follower for a door closure, comprising a body member having an axis and adapted to be supported in a body part of the door closer for linear movement along the axis, and supporting a roller element for rotation about an axis extending transversely of the body member axis, wherein the axis of rotation of the roller element is able to be displaced laterally relative to the body member, between respective positions on opposite sides of the body member axis.
6. A roller cam follower according to claim 1 wherein the support member is able to move pivotally relative to the body member about the bearing ball, whereby the axis of rotation of the roller element is able to be displaced laterally relative to the body member, between respective positions on opposite side of the axis of the body member.
7. A roller cam follower according to claim 6 wherein the support member is constrained radially within the body member in the vicinity of the second end portion thereof, but is able to be displaced laterally within the body member at the open first end thereof.
8. A door closer comprising a body for mounting in relation to a door, a rotary member supported by the body for angular movement and arranged to be caused to undergo such angular movement as the door is opened and * * 20 closed, and a cam carried by the rotary member and having a cam surface engaged by a roller cam follower moveable within the body for causing displacement of an element for controlling motion of the door, wherein the *:*::* roller cam follower is as claimed in any one of claims 1 to 4. * ***
9. A door closer according to claim 8 wherein the roller cam follower *:.::: causes displacement of a spring element of the closer.

**.*** * S
10. A door closer including a body for mounting in relation to a door, a rotary member supported by the body for angular movement about an axis and arranged to be caused to undergo such angular movement as the door is opened and closed, a cam carried by the rotary member and having a cam surface engaged by a roller cam follower moveable within the body in accordance with angular movement of the rotary member to cause displacement of an element for controlling the motion of the door, wherein the roller cam follower is as claimed in any one of claims 5 to 7.
11. A door closer according to claim 10 wherein the cam follower causes displacement of a damping element of the closer.
12. A roller cam follower for a door closer, or a door closer incorporating same, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
13. Any novel feature or novel combination of features described herein and/or in the accompanying drawings. * ** * . S * *. a.. * * * a.. * .* a. a * ..SS * .. * a * * ..*.****