Patent Document

FIELD OF THE INVENTION  
       [0001]     This invention relates to a handle system for attachment to and rotation of a rotational shaft.  
       BACKGROUND OF THE INVENTION  
       [0002]     Many items of home and office equipment comprise enclosures which are normally shut, but which may be opened by manipulation of an access handle which is turned to release an associated mechanism. Such access handles are common, in particular in devices such as printers, photocopiers, fax machines and folder/inserter machines. Typically, the access handle is attached to a rotational shaft which forms part of a locking/release mechanism. Each handle has, essentially, two rotational orientations-open and closed. In the closed position, the handle is positioned to lock the mechanism in a closed or operational position which enables normal operation of the device in which it is located. In the open position, the associated mechanism becomes unlocked, allowing, for example, an access panel to be opened, a section of machinery to be removed, or a section of machinery to be moved from an operational position in which its performs normal function to an access position in which an operator may gain access to that machine section (as might be required in order to clear a jam or blockage or to replace print toner).  
         [0003]     Typically, such access handles might consist simply of a cylindrical knob which may be turned to the appropriate orientation in order to either open or close the associated mechanism. More commonly, these access handles comprises a lever arm attached at one end to the rotational shaft to thereby allow a user to apply a larger torque to the shaft.  
         [0004]     A typical arrangement might include an elongate lever arm attached to a cylindrical hub. The cylindrical hub has a hole therein which mates with a corresponding section on the shaft. In known handles, the hole has a D-shaped cross-section, and the corresponding shaft to which the handle is to be attached has a corresponding flattened section at one end to produce a D-shaped cross-section which mates with the D-shaped hole in the access handle.  
         [0005]     Whilst this arrangement works adequately, it nevertheless has disadvantages.  
         [0006]     In a device which has a plurality of access handles, it is likely that the handles will need to be located within the machine at various different orientations, both with respect to the machine itself and with respect to the flattened section of the rotational shaft. Thus, it is common that a separately-moulded handle element is required for each rotational shaft in the machine, each one of the handles having a hole with the D-shaped cross-section oriented at a different angle to the lever arm. This problem is particularly exacerbated by the manufacturing requirements of the rotational shaft. Theoretically, the flat portions of the rotational shaft could be oriented on each shaft in order that only a single design of handle would be needed. However, because of other components forming part of the rotational shaft, it is not always possible or economical to manufacture the shaft in this way, and the orientation of the flattened section of the shaft may be chosen purely for manufacturing reasons independent of alignment considerations with the handle.  
         [0007]     A further consideration is that it is often desirable to label the hub of the handle with an appropriate symbol, such as an arrow or lettering. The alignment of such labelling is therefore dependent not only upon the orientation of the D-shaped part of the rotational shaft, but also on the orientation of the handle lever arm when attached to the rotational shaft.  
       SUMMARY OF THE INVENTION  
       [0008]     A variable alignment handle is provided for attachment to a rotational shaft, the handle comprising:  
         [0009]     a lever handle, for attachment to the rotational shaft for aiding application of torque to the shaft; and  
         [0010]     an alignment boss, separate from the lever handle, for attaching the lever handle to the shaft and for aligning the lever handle at a predetermined orientation with respect to an alignment feature of the shaft.  
         [0011]     A method for attaching the handle is also disclosed to comprising the steps of: 
        i) sliding a lever handle component along the shaft from one end; sliding an alignment boss over the end of the shaft and obtaining rotational alignment of     ii) the boss with a shaft alignment feature; and     iii) sliding the boss along the shaft from the end of the shaft to force the boss into engagement with the lever handle to align the lever handle at a predetermined orientation with respect to an alignment feature of the shaft.       
 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]     For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:  
         [0016]      FIG. 1  is a perspective view of an embodiment of the present invention in disassembled form;  
         [0017]      FIG. 2  is a cross-sectional view of the embodiment of  FIG. 1  showing the fully-assembled handle;  
         [0018]      FIG. 3  is a perspective view showing the detail of one component of the embodiment of  FIGS. 1 and 2 ; and  
         [0019]      FIG. 4  is a plan view of the component of the embodiment of FIGS.  1  to  3  showing the relative orientation of two of the components. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]     Throughout the drawings, the same reference numerals are used to describe the same or like features. A single embodiment is shown throughout FIGS.  1  to  4 . However, this embodiment should not be taken to be limiting and is used purely as an exemplary embodiment in order to improve understanding of the present inventive concept.  
         [0021]     As seen in  FIG. 1 , the handle of the instant embodiment comprises two components: a lever handle  20  and an alignment boss  30 . The two components are sized and dimensioned for attachment to a rotational shaft  10 . In order to assemble the handle to the shaft, the lever handle  20  is first slid over one end of the shaft  10  and part way there along. The alignment boss  30  is then slid over the same end of the shaft  10  and simultaneously engages both the lever handle  20  and the shaft  10 , thereby fixing the relative orientation between the shaft  10  and the lever handle  20  and preventing further axial or rotational movement of the lever handle  20  relative to the shaft  10 .  
         [0022]     Considering the components in more detail, with reference to FIGS.  1  to  4 , the lever handle  20  comprises a tubular engagement portion  21  which has a substantially cylindrical outside surface from which a lever arm  22  extends in a radial direction. The tubular portion  21  is open at both ends and has a hole running along the length thereof. The tubular portion has two end faces  21   a  and  21   b . The hole in the first end face  21   a  has a cross-section which is substantially key-hole shaped, formed of a circular portion and a comparatively small rectangular portion  23  extending therefrom in one direction. In the illustrated embodiment, rectangular portion  23  is aligned with lever arm  22 . The circular portion of the key-hole shaped opening has a larger diameter than the shaft  10  to which the handle is to be attached. At the other face  21   b  of the lever handle, the hole is approximately equal in diameter to the shaft  10  due to a lip (seen in  FIG. 2 ) extending from the inner face of the key-hole shaped opening in the tubular section  21 . This lip abuts the shaft  10  when the handle is attached thereto. Extending axially into and along the key-hole shaped opening from the lip are a plurality of fingers  24  which engage with a snap ring groove  11  in the shaft  10 . The fingers comprise an axial portion which has a barb at one end that locks into the snap ring groove  11 .  
         [0023]     The alignment boss  30  comprises a tubular section  31  which is essentially cylindrical in shape. The tubular section is open at one end and closed at the other end by a cap  32 . The cap  32  may be embossed, printed or otherwise marked on an external surface thereof with a symbol, letter or other mark represented here by an arrow  33 . As can be seen from  FIG. 3 , the tubular portion  31  has an inner surface  34  which is substantially D-shaped in cross-section. This hole corresponds to a portion  12  of the shaft  10  which has a D-shaped cross-section where a portion of the shaft has been flattened. When the alignment boss  30  is slid over the end of the shaft  10 , the hole  34  must be aligned with the D-shaped end section to mate the boss to the shaft to prevent relative rotation between the shaft and alignment boss. The outer surface of the tubular section  31  is substantially cylindrical except for an engagement portion comprising axially extending ridges  35   a  and  35   b . These ridges align with the rectangular notch  23  in lever handle  20  when the alignment boss  30  is inserted into the key-hole shaped opening in the lever handle. This prevents relative rotation between the alignment boss  30  and the lever handle  20 . At the open end of the tubular section  31 , the two ridges  35   a  and  35   b  are joined by a web  36 . When the alignment boss is pushed into the key-hole shaped opening in the lever handle  20 , the web  36  engages a snap fit element  25  in the lever handle which locks the alignment boss in place to prevent it being axially removed from the lever handle  20 .  
         [0024]     Extending axially along the D-shaped hole in tubular section  31  of the alignment boss  30  is a plurality of pockets  37  corresponding to the plurality of engagement fingers  24 . Each pocket has an opening which is deeper at the open end of the tubular section  31  and becomes shallower towards the cap end of the tubular section, as best seen in  FIG. 2 . As the alignment boss is pushed into engagement with the lever handle, each of the engagement fingers  24  is received within one of the pockets  37 . As the alignment boss is pushed into the lever handle, the inclined inner surfaces of the pockets  37  act as camming surfaces to force the engagement fingers  24  radially inwardly and press the engagement fingers against the shaft  10 . This locks the barb portion of each finger into the snap ring groove  11 , preventing the lever handle from moving axially relative to the shaft  10 .  
         [0025]     Once the handle is fully assembled, the fingers  24  and pockets  37  prevent the lever handle from moving axially relative to the shaft by engaging the snap ring groove  11 , whilst the engagement between the snap fit element  25  and the web  36  prevents the alignment boss  30  from being retracted axially from the lever handle  20 . Therefore the handle is now locked axially onto the shaft  10 . The rotational orientation of the alignment boss is fixed relative to the shaft  10  by the mating alignment of D-shaped section  12  of the shaft and D-shaped hole  34  of the alignment boss. This prevents relative rotation between the shaft and alignment boss. The lever handle  20  has a fixed orientation relative to the alignment boss  30  due to engagement of ridges  35   a  and  35   b  with the rectangular groove  23  in the lever handle  22 . This prevents relative rotation between the alignment boss and lever handle. Thus, the lever handle  22  has a fixed orientation relative to the shaft  10  due to mutual engagement with alignment boss  30 .  
         [0026]     The lever arm  22  allows sufficient torque to be readily applied to the lever handle in order to rotate the shaft  10 . This force is transmitted to the shaft  10  from the lever handle  20  via ridges  35   a  and  35   b  in the alignment boss and subsequently via the engagement of the flat portion of the D-shaped cross-section portion of the shaft with D-shaped hole  34  in the alignment boss. The fingers  24 , therefore, need not be configured to transmit any of the applied torque between the lever handle  20  and alignment boss  30 , although this is possible.  
         [0027]     In order to assemble the handle onto the shaft, the lever handle  20  is first slid onto the shaft so that the fingers  24  engage with the snap ring groove  11  of the shaft, preventing axial movement of the lever handle relative to the shaft. Next, the alignment boss  30  is slid over the end of the shaft and is then rotated in order to align the D-shaped hole  34  with D-shaped portion  12  of the shaft. Once these portions have been correctly aligned, the lever handle  20  is rotated relative to the shaft  10  and alignment boss  30  in order to align the rectangular portion  23  of the key-hole shaped opening in the lever handle with the ridges  35   a  and  35   b  of the alignment boss. This automatically aligns each of the engagement fingers  24  of the lever handle with the pockets  37  in the alignment boss  30 . The alignment boss  30  is then pushed fully onto the shaft  10 , which forces it into the key-hole shaped opening in the lever handle  20 . This forces the engagement fingers  24  into permanent pressing engagement with the snap ring groove  11 , and locks the alignment boss  30  into the lever handle  20  due to engagement of snap fit element  25  of the lever handle with web  36  of the alignment boss.  
         [0028]     A feature of the present design is that it allows a number of alignment bosses to be produced which each have the D-shaped hole at a different orientation to the ridges  35   a  and  35   b . Thus, any desired alignment may be achieved between rotational shaft  10  and lever handle  20  by appropriately selecting an alignment boss  30  which has the D-shaped hole and ridges  35   a  and  35   b  appropriately aligned. Further, this allows the symbol  33  on the cap  32  of alignment boss  30  to be appropriately oriented for each of the produced alignment bosses, such that the marking, when the handle is assembled, will have the correct orientation relative to the shaft  10  (and ultimately the device in which it is installed).  
         [0029]     This arrangement is advantageous since it avoids the need to produce a different handle design for each angular orientation relative to the shaft or for each shaft to be adjusted at the handle end. In the situation where a unitary handle is produced which may be attached to a shaft at a number of different orientations, the possibility arises that the handle may be incorrectly attached to the shaft at an undesirable orientation. This possibility is removed according to the present handle system because each lever handle  20  has only a single orientation which is defined by the chosen alignment boss  30 . In the second situation, where the shafts are simply machined so as to have the D-shaped portion  12  at the correct orientation, machining costs can be increased. This is due to the nature of various other components located along the shaft which may have complex and inter-related machining requirements.  
         [0030]     The interaction between the engagement fingers  24  and the pockets  37  means that the lever handle is held extremely securely onto the shaft  10  in the axial direction by engagement with the snap ring groove  11 .  
         [0031]     Because each of the alignment bosses is produced separately for each of the shafts in a machine, the label  33  may be appropriately chosen. Appropriate labels might be numbers or lettering indicating the part of the machine where the handle is located when assembled. Alternatively, the label  33  might be an appropriate symbol, such as an arrow to indicate various orientations of the handle. A further possibility is to apply a trade mark to the cap  32  of the alignment boss  30 , in order to improve brand recognition. The label may be applied to the alignment boss by a variety of means, such as printing, embossing, moulding etc.  
         [0032]     In the described embodiment, three engagement fingers  24  are depicted within the lever handle  20 , along with three corresponding pockets  37  in the alignment boss. However, the number of fingers is chosen as a matter of preference and in accordance with the chosen material from which the handle is to be manufactured. The inventors have found that preferable results are achieved when the number of engagement fingers is between 3 and 5.  
         [0033]     Although the engagement between the lever handle  20  and alignment boss  30  has been described as engagement of the web  36  by the snap fit element  25 , alternative known methods may be used, such as an interface fit or interlocking annular rings which may be snapped into place. Further, the exact shape of the components is not critical. In particular, a lever handle could be created having a plurality of lever arms  22  extending from the tubular portion  21 .  
         [0034]     Whilst the above-described embodiment uses a D-shaped cross-section to achieve a mating engagement between the alignment boss  30  and the rotational shaft  10 , the invention is not limited to this shape, and any suitable mating engagement may be chosen. Similarly, the described embodiment utilises an alignment boss having a cap  32 . This limits the application of the handle to attachment at the end of the shaft  10 . However the attachment mechanism by which the handle becomes locked to the shaft could be applied to a handle located at any point along the shaft, providing that appropriate mating features are chosen for the shaft  10  and alignment boss  30 . In this case, the cap  32  of alignment boss  30  is not used.

Technology Category: 3