BRIEF DESCRIPTION OF THE DRAWINGS
The objects, features, and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments and certain modifications thereof when taken together with the accompanying drawings in which like numbers represent like items throughout and in which:
FIG. 1 is a perspective view of the fully assembled power pack in conjunction with a door lever, spindle and tubular latch.
FIG. 2 is a perspective view of the power pack assembly in conjunction with a spindle.
FIG. 3 is perspective view of the power pack in conjunction with a spindle and with the cover plate removed and the springs omitted.
FIG. 4 is an isolated perspective view of the slide arms with the springs and other elements omitted.
FIG. 5 is a front view of the power pack with the cover plate removed and the springs inserted.
FIG. 6 is an isolated perspective view of the slide arms with the springs and spindle hub included.
FIG. 7 is a front view of the power pack with the cover plate removed in a displaced condition.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the exemplary embodiment illustrated in the drawings and described below. The embodiment disclosed is not intended to be exhaustive or limit the invention to the precise form disclosed in the following detailed description. Rather, the embodiment is chosen and described so that others skilled in the art may utilize its teachings. It will be understood that no limitation of the scope of the invention is thereby intended. The invention includes any alterations and modifications in the illustrated device, the methods of operation, and further applications of the principles of the invention which would normally occur to one skilled in the art to which the invention relates.
The invention is a power pack assembly for biasing a primary door opening mechanism to a neutral or home position after being manually displaced from the home position, and for retaining the primary mechanism in that home position despite ambient forces (such as the force of gravity acting on the door lever), until such time as additional manual force is applied to again operate it. Displacement of the primary mechanism may be rotational or angular displacement about an axis, or linear displacement. As depicted in FIG. 1, the invention is described herein in the context of a door handle set, with a latch being the primary mechanism, such that angular rotation of a spindle 30 in response to operation of a door lever 32 to retract the bolt 31 of tubular latch 34 is contemplated. The power pack assembly 10 according to the present invention is low-profile, may be countersunk into the door, and serves to return the door lever 32 (or a door knob) to a generally horizontal home position after the latch has been operated and assists in returning the bolt 31 to the extended position.
FIG. 2 depicts the power pack assembly 10 isolated from the door lever 32 and latch 34 but with spindle 30 in place. A housing 12 is provided. Housing 12 is preferably circular in form having a diameter of less than 2⅛ inch so as to be partially recessed within the standard size holes provided within commercial doors for installation of the handle set. Housing 12 may be integrally formed with a decorative rose plate 33 for flush seating on the surface of the door around the handle set knob or lever 32. A plurality of holes 14 may be provided through the housing 12 for securing the housing directly to the door, or as illustrated through-bolting through the tubular latch 34 to a cooperative rose plate on the opposite side of the door. The housing 12 includes a removable cover plate 16 for easy assembly and servicing of the power pack 10.
With the cover plate 16 removed, as depicted in FIG. 3, slide arms 20 are visible, slideably retained within the housing 12. The compression springs (described below) have been omitted for clarity in this view. With further reference to FIG. 4, the slide arms 20 include a first arm 22 and a second arm 24 slideably interlocked together. Arms 22, 24 each have a primary longitudinal frame member 23, 25, respectively. Frame members 23, 25 are a disposed to engage one another while permitting relative sliding of the arms 22, 24 along their longitudinal axes. As depicted, one frame member 23 is provided in the form of a narrow central rail running between orthogonal flanges 26, 27 at either end. The other frame member 25 is depicted as a spaced pair of upper and lower rails running between orthogonal flanges 28, 29 at either end. The upper and lower rails of frame member 25 are spaced to receive the central rail of frame member 23. Flange 27 is truncated where it joins frame member 23 to provide clearance to allow the upper and lower rails of frame member 25 to pass.
Flanges 26, 27, 28, 29 anchor compression springs (not shown in this view), and for this purpose may be generally orthogonal tabs projecting from their respective frame members. However, the flanges 26, 27, 28, 29 may take other forms including protrusions, hooks, pins or any other means for retaining a spring including tack welds of the spring ends directly to the respective frame members. As stated, first and second arms 22, 24 are interlocked such that flange 28 is situated between flanges 26 and 27. Similarly, flange 27 is situated between flanges 28 and 29, as best seen in FIG. 4. It should be observed that first and second arms 22, 24 need not be directly interlocked with one another as depicted herein but rather may be engaged by being separately slideably retained within, for example, a housing such that that their flanges 26, 27, 28, 29 are interposed as described above. First and second arms 22, 24 are, in such an embodiment, mechanically linked by the compression springs alone, as described below.
FIG. 6 illustrates two compression springs 42, 40 mounted in the slide arms 20 between the flanges 26, 27, 28, 29. A first compression spring 42 is thus retained between flange 26 and flange 28, while a second compression spring 40 is retained between flange 27 and flange 29, the first and second arms 22, 24 being mechanically linked and biased apart by compression springs 40, 42.
With reference to FIGS. 3 and 5, a spindle hub 36 is rotatably mounted within housing 12. Spindle hub 36 receives the keyed spindle 30 mechanically linking the power pack 10 with door lever 32. The spindle 30 is keyed to the spindle hub 36, generally having a non-round cross-section (for example, square as shown), and spindle hub 36 is cooperatively shaped to receive and rotate with the spindle 30. Spindle hub 36 is further provided with a cam 38 extending radially from the spindle 30 to engage the slide arms 20. Specifically, as best seen in FIG. 6, cam 38 extends between the two center flanges 27, 28. This way, as door lever 32 is rotated the spindle hub 36 is rotated in the same direction via the spindle 30 thereby rotating and laterally displacing the cam 38. Cam 38 is sized to provide the necessary lateral displacement of the cam to engage the slide arms 20. The greater the maximum length of the cam 38 from the rotational center of the hub the greater the lateral displacement cam 36 and slide arms 20 and thus the greater the compression of the springs 40, 42, as further described below.
Counterclockwise rotation of cam 38 engages the first slide arm 22 at flange 27, and clockwise rotation of cam 38 engages the second slide arm 24 at flange 28. Thus, as depicted in FIG. 7, clockwise rotation of the spindle hub 36 forces flange 28 to slide into and compress first spring 42 between itself and flange 26, flange 26 being held in place by the housing 12. At the same time, sliding of flange 28 draws flange 29 in the same directing via frame member 25, thereby simultaneously compressing second spring 40 between flange 29 and flange 27, flange 27 being held in place via frame member 23 and flange 26 contacting the housing 12. The compression of first and second springs 42, 40 creates potential energy, and springs 42, 40 return-bias second arm 24 to the home position when the door lever 32 is released thereby forcing the lever 32, via the hub 36 and spindle 30, back to its neutral horizontal position and retaining it in that position indefinitely.
Rotation of the spindle hub 36 in the opposite direction produces a like result, with cam 38 forcing flange 27 to slide into and compress second spring 40 between itself and flange 29, which is held in place by the housing 12. At the same time, sliding of flange 27 draws flange 26 in the same directing via frame member 23, thereby simultaneously compressing first spring 42 between flange 26 and flange 28, flange 28 being held in place via frame member 25 and flange 29 contacting the housing. Potential energy again stored in first and second springs 42, 40 likewise returns and maintains first arm 22 and thus door lever 32 in the home position when the door lever 32 is released.
One skilled in the art will now see that the foregoing configuration provides compression of both compression springs 40, 42 regardless of which direction the spindle 30 is rotated thereby providing maximum reverse bias return the spindle 30 and any knob or lever connected thereto to the rest position. This produces twice as much force as would be possible using independent springs of the same length, and entirely eliminates the need for more expensive and less reliable expansion springs or torsion springs yet applies the entire righting force of both springs in compression only leading to more both reliable operation and less expensive manufacture. The forgoing design further simplifies the mechanisms of the prior art, reducing the total number of parts thereby providing smoother operation and reduced wear cost.
Having now fully set forth the preferred embodiment and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with said underlying concept. It is to be understood, therefore, that the invention may be practiced otherwise than as specifically set forth in the appended claims and may be used with a variety of materials and components. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.
Patent Application
20100264672
