A drive gear for a roller door operator
This invention relates to improvements in door operators and more particular operators for roller doors.
A door operator basically provides a motorised drive for 5 opening and closing a door and incorporates control means whereby the motor can be activated remotely. Often such controllers are a retrofit item. To retrofit a door operator involves a good deal of time and expertise on the part of the fitter, lϋ
With roller doors it is normal for the fitter to remove the roller door from its mounting brackets so that a drive gear can be fitted on the axle of the door. With the door back in position the fitter can then mount the 15 drive unit and couple it to the drive gear. This operation is time consuming, can be labour intensive and requires a degree of skill and expertise on the part of the fitter.
20 An objection of the present invention is to provide a drive gear which can be fitted to an axle of a roller door without the need for the axle to be removed from its mounting bracket.
25 Broadly in one aspect the present invention consists of a drive gear comprising at least two sections which when combined form a means for mounting the drive gear to an axle, shaft or like member and a gear wheel, there being
means for locking the sections together when combined to form said gear wheel and mounting means.
According to a second broad aspect the invention provides a door operator which includes a housing adapted for attachment to a mount said housing being characterised by a recess within which a part of the axle of a door can locate whereby the housing can be attached to a said mount with part of the door axle located in said recess.
Preferably the arrangement is such that the housing and mount cooperate to lock said axle in a fixed position relative thereto.
Preferably the housing incorporates a motor and a gearbox whereby drive can be transmitted through said gearbox to an output gear located externally of the housing. Preferably the motor is an AC motor.
According to a preferred form a removable light fitting is attached. to the housing. This can be achieved by a socket incorporated with the housing for attachment of the light fitting and to provide a power input for the light fitting. Preferably the light fitting includes an adjustable mount for adjustment of the orientation of the fitting relative to the housing.
In the following more detailed description of aspects of the invention reference will be made to the accompanying drawings in which:-
Figure 1 is a perspective exploded view of a door operator and roller shutter door,
Figure 2 is a plan view of a drive gear according to the present invention,
Figure 3 is an elevation view of the drive gear, Figure 4 is a cross section view, Figure 5 is an elevation view of one section of the drive gear.
Figure 6 is a plan view of a drive gear section according to a second embodiment of the invention, and Figure 7 is a section on line I-I of Figure 6.
In Figure 1 there is illustrated a roller door D having a shaft S which extends therethrough and is coupled to a dru wheel all in accordance with know constructions. The end of the shaft S which protrudes from the door curtain is typically located on an arm A which extends from a mounting portion M of a bracket B. Such a mounting bracket B and its arrangement for fixedly attaching the end of the shaft S is also in accordance with a typical or known construction. In use bracket B is mounted via mounting portion M to a structural or frame member adjacent the door opening.
The door operator 10 comprises a housing 11 inside of which is located a drive motor (preferably an AC motor), gearbox and electronic controls. The gearbox and electronic control can be in accordance with our New Zealand patent specifications 233965 and 248231. A release arm 13 projects from housing 11 such that the gearbox can be disconnected in accordance with the disclosure in patent specification No. 233965. The gearbox output shaft (not shown) projects through a suitable opening in housing 11.
Formed in the portion of the housing 11 which essentially forms the floor 15 thereof is a recess 12. This recess 12 is of a width and is curved at its inner end such as to conform with the diameter of shaft S.
Projecting downwardly from the floor 15 of housing 11 are a pair of threaded studs (not shown). The studs can be formed by a conventional U bolt which would normally be used for engaging about shaft S and fitted through slot 16 of arm R so as to fixedly attach the shaft S in position. The positioning of the studs can be adjustable.
Thus a novel arrangement of door operator is provided whereby the housing 11 is mounted onto arm A with shaft S engaging through recess 12. The downwardly depending studs pass through slot 16 and nuts are screwed thereon and tightened. The net result is that simultaneously
housing 11 is fastened to arm R and shaft S, by being located in recess 12, is fixedly located against transverse and longitudinal movement relative to arm R.
One significant advantage of locating shaft S through recess 12 is that the relative position of shaft S and housing 11 •is such that the output shaft of the operator has an axis of rotation which is parallel to the central longitudinal axis of shaft S. As a consequence the relative position of shaft S and the housing 11 is always "true".
An output gear 17 locates on the output shaft of the operator. This output gear 17 engages in a planetary arrangement with a drive gear 18. The drive gear 18 is, in accordance with conventional practice, located between arm R and drumwheel P so that conventional drive fingers (not shown) can extend from the drive gear 18 to engage with one or more of the radial spokes P' of drumwheel P.
According to the present invention a novel drive gear 18 is provided and reference is in particular made to Figures 2-5.
The drive wheel 18 is of multi section construction though in the illustrated arrangement it is formed by two identical sections 19.
Each section comprises a floor 20 from which extends a peripheral wall 21. On the inside surface of wall 21 a plurality of teeth 22 are formed. Extending from floor 20 is an annular boss 23 having an internal radius substantially the same or slightly larger than that of shaft S.
Edge surface 25 of floor 20 is formed, to one side of boss 23, with a series of T shaped projections 26 while to the other side of the boss 23 edge 25 is formed with a plurality of correspondingly shaped grooves 27. Between adjacent T shaped projections 26 are straight sided grooves 28 while adjacent the T shaped grooves 27 are correspondingly shaped straight sided projections 29.
The drive gear is assembled by positioning edges 25 adjacent one another but offset. By sliding the edges 25 relative to one another the T shaped and straight sided projections 26 and 29 slide into the respective grooves 27 and 28 as can be seen in Figure 2.
To retain the assembled drive gear in its assembled state clips 30 which are of substantially U shape with small returns at the ends of their legs slide over T shaped projections 31 formed at the periphery of both the boss and wall 21 when the two sections 19 are joined together. As shown in Figure 3 each clip 30 includes a flap 32 which
engages into a recess (not shown) in each of T shaped projections 32 so as to prevent the clip from disengaging from the T shaped projection.
The outer surface of floor 30 is provided with a land 34 having a pair of spaced apart projecting pins 35 and an opening 36 located therebetween. These elements combine to form a mounting for the base of a finger arrangement (not shown) used to couple the drive gear 18 to drumwheel P. Other arrangements to facilitate this connection can be used and the land, pins and centrally disposed opening are by way of example only.
In accordance with the present invention a fitter merely locates each section 19 about shaft S and couples the two sections together as described above. The two sections are then clipped together via the clips as described above. Thus removal or uncoupling of the shaft S from the bracket B is not required in order to facilitate attachment of the drive wheel 18 to the shaft S. This significantly reduces time, labour content and other factors which are typically associated with currently methods of retrofitting a drive wheel for a door operator to a roller door.
The present invention also incorporates a novel light arrangement. With known door operators the light is normally incorporated within housing 11 with the result that
in some situations the light is not correctly directed and indeed can be positioned such that it is largely ineffective. Accordingly the present invention provides a light fitting 40 having a plug 41 formed as part of an adjustable mount 42. The plug 41 fits into a socket (not shown) in floor 15 of housing 11 whereby the light fitting 40 is mounted in position and also derives power for the light bulb.
Consequently once the operator 10 has been mounted in position the fitter can merely plug fitting 41 into place and by manipulating the adjustable mount 42 can direct the light to obtain the optimum illumination.
The invention is open to modification within the scope of the claims as will be apparent to the skilled person. For example, a modified form of the drive gear section is shown in Figures 6 and 7. According to this form of the invention the edges 25 of the two sections 19 are simply butted together. Axial movement of the two sections relative to one another is prevented by a projection 43 fitting into a similarly shaped recess 44 when the two sections are brought into butting edge 25 to edge 25 relationship. Instead of clips to hold the two sections together mechanical fasteners (eg nut and bolt assemblies) engage through aligned openings 45 in flanges 46.
Also the mounting for the drive finger assembly is different in the embodiment in Figures 6 and 7. In this arrangement openings 47 are provided so that the finger assembly can be simply bolted into place. However, a locating lug or nipple 48 is preferably provided to locate the finger assembly in place.
By virtue of the mounting of the operator 10 on the arm R of bracket B, the ability to assemble the drive gear 18 onto the shaft without removal of the shaft from the bracket B and the clamping of the shaft S by recess 12 in housing 11 the whole mounting procedure is straight forward and is one which ensures alignment between the drive gear and the output gear. Accordingly fitting is a straight forward and less time consuming exercise than with operators hitherto known.
Also a compact and aesthetically pleasing assembly is achieved. Furthermore the compactness of the total arrangement leaves sufficient clearance for a housing incorporating an AC motor. Typically AC motors have not been useable in such situations due to their bulk over and above DC motors. With an AC motor better output power from the operator is achievable.