Method and apparatus for security gate gearing

Abstract

A security gate drive mechanism is disclosed having a rotating shaft which rotates no more than a single rotation in order to provide through a linking mechanism, a driving force to move a security gate from a first position in which the security gate is essentially fully closed, to a second position in which the security gate is essentially fully open. A driving motor having a drive shaft rotating at much greater than one revolutions per minute, and a reduction gear contained in a reduction gear housing having an input shaft operatively connected to the drive shaft and an output shaft comprising or operatively connected to the rotating shaft, thus reducing the revolutions per minute of the drive shaft to a number of revolutions per minute suitable for operation of the security gate.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to the field of security gate operating mechanism.

BACKGROUND OF THE INVENTION

[0002] It is well known to provide a security gate in which a drive motor is used to operate a drive shaft, which is connected through a reduction gear typically connected to a second reduction gear for example by a pulley system. In this fashion the high rotational speed of the drive motor in RPM or, e.g., 1650 can be reduced to a speed of something in the neighborhood of one RPM for the operating shaft of the operating mechanism to rotate. This operating shaft is attached typically to a hinged operating arm that moves the security gate from a first essentially fully closed position to an essentially fully open position through a single revolution of the operating shaft or somewhat less that a single revolution. This same arrangement can also be used with a sliding security gate and the speed of the operating shaft reduced to several RPM. Using a single reduction gear has proved to be not feasible, since the size of the teeth in, e.g., a worm gear reduction gear would be so small that they would not be able to bear the load of swinging a large security gate from open to closed or vice-versa. This particular shortcoming of the prior art systems becomes exacerbated in the event that there is a obstacle blocking movement of the gate or for some other reason, e.g., accumulations of ice, snow or dirt or other debris on the gate, causing higher than normal torque to be exerted on the reduction gear. This can cause jamming or worse damage to the reduction gear. Therefore, it has been found to be necessary to use at least two reduction gears, e.g., one with a 60:1 ration and one with a 30:1 ratio. While this achieves the goal of reducing, e.g., a motor drive shaft rotation from e.g., 1650 RPM to 0.91 RPM, this can be a cumbersome and bulky arrangement.

[0003] The present invention solves the shortcomings of the prior art arrangements.

SUMMARY OF THE INVENTION

[0004] A security gate drive mechanism is disclosed having a rotating shaft which rotates no more than a single rotation in order to provide through a linking mechanism a driving force to move a security gate from a first position in which the security gate is essentially fully closed to a second position in which the security gate is essentially fully open, a driving motor having a drive shaft rotating at much greater than one revolutions per minute, and a reduction gear, contained in a reduction gear housing, having an input shaft operatively connected to the drive shaft and an output shaft comprising or operatively connected to the rotating shaft, for reducing the revolutions per minute of the drive shaft to a number of revolutions per minute suitable for operation of the security gate, and including a gearing mechanism comprising: a drive shaft pulley fixedly attached to the drive shaft for rotation with the rotation of the drive shaft; a reduction gear pulley having a larger diameter than the drive shaft pulley and extending outside of a projection of the reduction gear housing at least in a direction generally aligned with the axis of rotation of the reduction gear output shaft; a reduction gear housing extension connected to the reduction gear housing and extending in the direction of the extension of the reduction gear output shaft from the reduction gear housing, and having an opening through which extends the reduction gear output shaft; the reduction gear housing extension extending a sufficient distance to at least place the respective extension of the reduction gear pulley within the projection of the reduction gear housing extension. The reduction gear housing extension may also have a bearing mounted in the opening adapted to rotationally support the reduction gear output shaft. The reduction gear pulley together with the drive shaft pulley may provide at least a two to one reduction in the revolutions per minute on the drive shaft to the revolutions per minute on the reduction gear input shaft. The reduction gear pulley together with the drive shaft pulley provide at least a four to one reduction in the revolutions per minute on the drive shaft to the revolutions per minute on the reduction gear input shaft.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] FIG. 1 shows a partially cut-away plan view of a security gate drive mechanism gearing arrangement according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] Turning now to FIG. 1 there is shown a security gate driving mechanism gearing system 10 according to the present invention. The gearing system can include a motor 12 and an operating shaft 14. The operating shaft 14 needs to be driven at a rotational speed of about one RPM in order to rotate a pivoted arm (not shown) from a first position to a second position, with the first position, e.g., corresponding to the security gate being in one of a fully open or fully shut position and the second position corresponding, e.g., to the security gate being I the other of the fully open or fully shut positions.

[0007] The operating shaft 14 is connected to the motor 12 through a reduction gear 20, contained within a housing 22, and comprising, e.g., a worm gear reducing the rotational speed of an input shaft 24 in regard to the operating shaft 14 by, e.g., a 60:1 ratio. The input shaft 24 can be driven by an input shaft pulley 26 which can be connected to a drive shaft pulley 28 connected to a drive shaft 30 of the motor 12 by a pulley belt 40. The input shaft pulley 26 is sized to have, e.g., an 8:1 speed reduction of the input shaft 24 vis-a-vis the motor drive shaft 30, such that if the speed of the motor used were, e.g., 800 RPM and a reduction gear with a 60:1 reduction ration along with, e.g., an 8:1 reduction ration of the input shaft pulley 26 to the drive shaft pulley 28 (i.e., an 8 inch diameter input shaft pulley 26 and a one inch diameter drive shaft pulley 28) the resulting rotational rate of the operating shaft can be reduced to 1.71 RPM.

[0008] In order to accomplish this, with the known arrangements for the reduction gear connected to the operating shaft 14 in the prior art (not shown) space must be provided for the enlarged input shaft pulley 26 according to the present invention. In the past the input shaft pulley and the drive shaft pulley were approximately the same size, e.g., between one and two inches in diameter. At such size, any swinging arm (not shown) or sliding gate pulley/sprocket and chain (not shown). In the known art, for purposes of compactness, these items are generally attached to the operating shaft 14 in as close a proximity to the reduction gear housing 22 as is mechanically possible.

[0009] In order to implement the present invention, the operating shaft is extended, as shown in FIG. 1 to extend through a housing extension 44, in an opening therein provided with a bearing 46, which operates in conjunction with the existing bearing 42 contained in the reduction gear 20 housing 22 as shown in partial cut-away view in FIG. 1, to support the extended operating shaft 14. It will be understood by those skilled in the art that the operating shaft 14 may already be of sufficient length to not need an extension, and that if an extension is needed, the extension may be formed in a variety of known ways, e.g., threaded on to the existing operation shaft 14, welded on to the existing operating shaft 14 replacing the existing shaft 14 with one of longer length, etc. The extension 44 and extended length operating shaft 14 serve to place the maximum radial displacement of the input shaft pulley (and if necessary the belt as seated on the pulley) at a minimum within a lateral projection 50 of the extension 44. In this manner, the larger input shaft pulley can be accommodated without interfering with either a swinging arm of sliding gate drive chain, or the like operatively attached to the operating shaft. 14.

[0010] Those skilled in the art will appreciate that, depending upon the manner in which the operating shaft 14 is extended there may not be the opportunity to employ the bearing 42. If the extension is rigidly coupled to the original shaft or the original shaft is replaces with a longer single piece shaft, then the intermediate bearing 42 may not be useable. any warping of the operating shaft 14 could cause the failure of the intermediate bearing 42, dues to overloading and stress. In this event, the original end-plate 23 of the housing 22 of the reduction gear 20, in which is seated the intermediate bearing 42, may simply be replaced with a new end plate (not shown) that extends the length of the housing 22 and in which is seated the bearing 46. On the other hand, if a flexible or other coupling is used to attach an operating shaft 14 extension which can accommodate an intermediate bearing without damaging it, then the extension housing 44 can simply be added on to the end of the reduction gear, as shown.

[0011] The present invention has been described in regard to a presently preferred embodiment of the invention but should not be limited only to this preferred embodiment. Other modification and changes to the concept of the presenting invention as embodied in the presently preferred embodiment will be understood by those skilled in the art to be possible. Such modifications will be understood to be part of the present invention and included within the literal language of the claims and/or equivalents of elements of the claims.

Claims

1. In a security gate drive mechanism having a rotating shaft which rotates at a relatively low rate of rotation in order to provide through a linking mechanism a driving force to move a security gate from a first position in which the security gate is essentially fully closed to a second position in which the security gate is essentially fully open, a driving motor having a drive shaft rotating at much greater than the desired rotation rate, and a reduction gear, contained in a reduction gear housing, having an input shaft operatively connected to the drive shaft and an output shaft comprising or operatively connected to the rotating shaft, for reducing the revolutions per minute of the drive shaft to a number of revolutions per minute suitable for operation of the security gate, a gearing mechanism comprising:

a drive shaft pulley fixedly attached to the drive shaft for rotation with the rotation of the drive shaft;

a reduction gear pulley having a larger diameter than the drive shaft pulley and extending outside of a projection of the reduction gear housing at least in a direction generally aligned with the axis of rotation of the reduction gear output shaft;

a reduction gear housing extension connected to the reduction gear housing and extending in the direction of the extension of the reduction gear output shaft from the reduction gear housing, and having an opening through which extends the reduction gear output shaft;

the reduction gear housing extension extending a sufficient distance to at least place the respective extension of the reduction gear pulley within the projection of the reduction gear housing extension.

2. The apparatus of claim 1 wherein the reduction gear housing extension has a bearing mounted in the opening adapted to rotationally support the reduction gear output shaft.

3. The apparatus of claim 1 wherein the reduction gear pulley together with the drive shaft pulley provide at least a two to one reduction in the revolutions per minute on the drive shaft to the revolutions per minute on the reduction gear input shaft.

4. The apparatus of claim 2 wherein the reduction gear pulley together with the drive shaft pulley provide at least a two to one reduction in the revolutions per minute on the drive shaft to the revolutions per minute on the reduction gear input shaft.

5. The apparatus of claim 1 wherein the reduction gear pulley together with the drive shaft pulley provide at least a four to one reduction in the revolutions per minute on the drive shaft to the revolutions per minute on the reduction gear input shaft.

6. The apparatus of claim 2 wherein the reduction gear pulley together with the drive shaft pulley provide at least a four to one reduction in the revolutions per minute on the drive shaft to the revolutions per minute on the reduction gear input shaft.

7. In a security gate operating mechanism having a drive motor operatively connected to an operating shaft through a reduction gear contained in a reduction gear housing, wherein the operating shaft is positioned and operatively connected to the security gate through a linking mechanism to move the security gate from a first position to a second position through rotary motion of the operating shaft, and wherein the revolutions per minute of the drive motor, without reduction, would rotate the operating shaft between a first position and a second position of the operating shaft corresponding to the security gate first and second positions, in an unacceptably fast manner, and wherein the linking mechanism extends generally perpendicularly to the axis of rotation of the operating shaft and generally parallel to a projection of the reduction gear housing in a first plane perpendicular to the axis of rotation of the operating shaft, a gearing mechanism comprising:

a reduction gear input pulley that is larger than a drive shaft pulley and operatively connected to the drive shaft pulley, and wherein the reduction gear input pulley extends beyond the projection of the reduction gear housing;

a reduction gear housing extension attached to the reduction gear housing in the vicinity of the operating shaft, whereby the linking mechanism extending generally parallel to a projection of the reduction gear housing extension is in a second plane perpendicular to the access of rotation of the operating shaft, and displaced from the first plane a distance sufficient to accommodate the increased size of the reduction gear input pulley.

8. The apparatus of claim 7 wherein the reduction gear housing extension has a bearing mounted in an opening through the reduction gear housing extension adapted to rotationally support the reduction gear output shaft.

9. The apparatus of claim 7 wherein the reduction gear pulley together with the drive shaft pulley provide at least a two to one reduction in the revolutions per minute on the drive shaft to the revolutions per minute on the reduction gear input shaft.

10. The apparatus of claim 8 wherein the reduction gear pulley together with the drive shaft pulley provide at least a two to one reduction in the revolutions per minute on the drive shaft to the revolutions per minute on the reduction gear input shaft.

11. The apparatus of claim 7 wherein the reduction gear pulley together with the drive shaft pulley provide at least a four to one reduction in the revolutions per minute on the drive shaft to the revolutions per minute on the reduction gear input shaft.

12. The apparatus of claim 8 wherein the reduction gear pulley together with the drive shaft pulley provide at least a four to one reduction in the revolutions per minute on the drive shaft to the revolutions per minute on the reduction gear input shaft.

13. A method of operating a security gate having a drive motor operatively connected to an operating shaft through a reduction gear contained in a reduction gear housing, wherein the operating shaft is positioned and operatively connected to the security gate through a linking mechanism to move the security gate from a first position to a second position through rotary motion of the operating shaft, and wherein the revolutions per minute of the drive motor, without reduction, would rotate the operating shaft between a first position and a second position of the operating shaft, corresponding to the security gate first and second positions, in an unacceptably fast manner, and wherein the linking mechanism extends generally perpendicularly to the axis of rotation of the operating shaft and generally parallel to a projection of the reduction gear housing in a first plane perpendicular to the axis of rotation of the operating shaft, comprising the steps of:

reducing the rotational speed of the motor drive shaft input to the reduction gear input shaft utilizing a reduction gear input pulley that is larger than a drive shaft pulley and operatively connected to the drive shaft pulley, and wherein the reduction gear input pulley extends beyond the projection of the reduction gear housing;

extending the reduction gear housing with an attached extension in the vicinity of the operating shaft, whereby the linking mechanism is enabled to clear the reduction gear input pulley in operation.

14. The method of claim 13 including rotationally support the reduction gear output shaft with a bearing mounted in an opening through the attached extension.

15. The method of claim 13 including provide at least a two to one reduction in the revolutions per minute on the drive shaft to the revolutions per minute on the reduction gear input shaft.

16. The apparatus of claim 14 including providing at least a two to one reduction in the revolutions per minute on the drive shaft to the revolutions per minute on the reduction gear input shaft.

17. The apparatus of claim 13 including providing at least a four to one reduction in the revolutions per minute on the drive shaft to the revolutions per minute on the reduction gear input shaft.

18. The apparatus of claim 14 including providing at least a four to one reduction in the revolutions per minute on the drive shaft to the revolutions per minute on the reduction gear input shaft.

19. In a security gate drive mechanism having a rotating shaft which rotates in order to provide through a linking mechanism a driving force to move a security gate from a first position in which the security gate is essentially fully closed to a second position in which the security gate is essentially fully open, a driving motor having a drive shaft rotating at much greater than one revolutions per minute, and a reduction gear, contained in a reduction gear housing, having an input shaft operatively connected to the drive shaft and an output shaft comprising or operatively connected to the rotating shaft, for reducing the revolutions per minute of the drive shaft to a number of revolutions per minute of the operating shaft suitable for operation of the security gate, a gearing mechanism comprising:

a drive shaft pulley fixedly attached to the drive shaft for rotation with the rotation of the drive shaft;

a reduction gear pulley having a larger diameter than the drive shaft pulley and extending outside of a projection of the reduction gear housing at least in a direction generally aligned with the axis of rotation of the reduction gear output shaft;

a reduction gear housing extension means for extending in the direction of the extension of the reduction gear output shaft from the reduction gear housing a sufficient distance to at least place the respective extension of the reduction gear pulley within a projection of the reduction gear housing extension.

20. The apparatus of claim 19 wherein the reduction gear housing extension means has a bearing mounted in the opening adapted to rotationally support the reduction gear output shaft.