Abstract:
The present invention is for an ambidextrous lockout switch system for use with a power tool. With the system of the present invention in place, a multi-step process must be carried out before the power tool can be activated. The system is adapted for the process to be carried out with either a left or a right hand. The present invention includes a handle body having a switch trigger or lever blockable by a barrier. The barrier is movable with either a left of a right lockout button, with the right lockout button being operably linked to the left lockout button. The system includes also a spring, which is mechanically coupled to the barrier. The spring effectively restores the barrier to a position in which the barrier blocks actuation of the switch trigger or lever.

Description:
FIELD OF THE INVENTION 
     This invention generally relates to safety lockout switches, and more particularly, to an ambidextrous switch lockout system. 
     BACKGROUND OF THE INVENTION 
     Some power saws, such as miter saws, have safety lockout buttons that require actuation before a power switch can be turned to the on position. Safety lockout buttons effectively minimize the probability of accidental tool activation by requiring the user to follow a sequence of at least two steps before activation. 
     Conventional lockout buttons are spring-loaded and include an internal blocking feature that mechanically interferes with the travel of a power switch trigger or lever. After the power switch is released to an off position, the system resets, and again requires at least two steps before the tool can be activated again. 
     Some conventional safety lockout systems include a removable button with a hole for receiving the button. When the removable button is not in place in the hole, the tool cannot be powered up. The removable button is intended to decrease the probability for accidental tool activation by adding an additional step to the process used for activating the tool. However, the removable button is an inconvenience if lost. A lost removable button can be more than an inconvenience, and may present a safety problem, for example, if users force other items into the hole to replace the lost removable button. 
     Power saws with vertical handles may also have a lockout button protruding from a left side of the handle, near the switch trigger. This conventional system is not ambidextrous. When used with a right hand, the lockout button is actuated by a thumb and the switch trigger by an index finger. When used with a left hand, the lockout button and switch trigger are usually both actuated by an index finger of the left hand. 
     The invention disclosed by U.S. Pat. No. 5,969,312 to Svetlik et al. (“the &#39;312 patent”) is for an ambidextrous lockout switch. Although the lockout switch of the &#39;312 patent can be operated by both a left handed user and a right handed user, and is in this sense “ambidextrous”, the method for using the ambidextrous lockout switch of the &#39;312 patent is substantially different for a right handed user than for a left handed user, and is not truly ambidextrous in this sense. In particular, a left handed user must rely on a “slide switch 22”, whereas a right handed user activates a “pressure button 23” for actuation. 
     There is, therefore, a need in the art for a switch lockout system that is convenient for use by both left and right handed users, and is actuatable in a substantially similar way by both left and right handed users. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides a generally balanced ambidextrous switch lockout system, actuatable in the same way by both left handed and right handed users. On a horizontally oriented handle, left handed and right handed users perform substantially the same steps to activate the power. The left side lockout button is identical to the right side lockout button in appearance and function. In the system of the present invention, both the left handed and right handed users press the right and left lockout buttons, respectively, with a thumb. The system of the present invention resets automatically after a switch lever or trigger is released. The system of the present invention may be added to a multi-position handle, which can be selectively oriented in a plurality of positions, including both horizontal and vertical positions. The present invention is ambidextrous, i.e., suitable for use by both left handed and right handed users, in any of the plurality of positions. 
     In a first embodiment, the present invention generally includes: a left lockout button, a right lockout button, a linkage, a centering spring, and a switch lever. The left lockout button is pivotally mounted to the left side of a horizontal handle with a protrusion from the left side of the handle. The protrusion on the left side of the handle is intended for thumb actuation by the right hand of a user when the handle is in a generally horizontal position. On a rotatable handle, when the handle is in a generally vertical position, the left lockout button is on top, and the one left lockout button may be activated by either a left handed user or a right handed user in substantially the same way. The left lockout button includes a barrier intended to stop actuation of the switch lever. The left lockout button has an aperture spaced apart from where the left lockout button is pivotally mounted. The aperture allows for a hinged connection to the linkage between the left lockout button and the right lockout button. The left lockout button also has two fingers that contact opposite ends of a centering spring. 
     The right lockout button is substantially a mirror image of the left lockout button, but without the barrier or the two fingers for contacting a centering spring. The thumb of the left hand of a user presses a protrusion from the right side of the handle. The right lockout button also has an aperture for mechanical coupling (through the linkage) between the left lockout button and the right lockout button. With both left and right lockout buttons mounted to the handle and the linkage connecting them, pressing the left lockout button causes the protrusion of the right lockout button to move leftwardly, and pressing the right lockout button causes the protrusion of the left lockout button to move rightwardly. 
     The centering spring is mounted to the handle in a spring mount, which holds a first and a second end of the spring. The spring mount is under the left lockout button, and has left and right ends, with interruptions in both left and right ends to allow the two fingers of the left lockout button to penetrate as the left lockout button moves. Pressing on the left lockout button causes the right finger to compress the centering spring to the left. Because of the linkage, pressing down on the right lockout button causes the left finger to compress the centering spring to the right. When neither the left lockout button nor the right lockout button has been pressed, both are held by the centering spring at a blocking position. At the blocking position, the barrier of the left lockout button blocks movement of the switch lever, preventing actuation of the switch lever. When the left lockout button is pressed, the barrier moves leftwardly, outside the switch lever, and allows the switch lever to be actuated. When the operably linked right lockout button is pressed, the barrier of the left lockout button moves rightwardly, inside the switch lever, and allows the switch lever to be actuated by an inward movement. 
     In a first embodiment, the present invention includes an ambidextrous lockout switch including a handle body with a first side and a second side, a switch, a barrier, a first lockout button, a second lockout button, and a spring. The switch is mounted to the handle body, and extends outwardly from the handle body. The switch can be actuated by an activating movement, which might be an inward, squeezing movement The barrier is mounted inside the handle body, and is movable from a blocking position in which the activating movement of the switch is blocked. The first lockout button is movably mounted to the handle body, and is adapted for moving the barrier in and out of the blocking position. Operably linked to the first lockout button is the second lockout button, with the second lockout button also adapted for moving the barrier in and out of the blocking position. The spring, which is mounted inside the handle body, is mechanically coupled to the barrier, and biases the barrier toward the blocking position when the barrier has been moved away from the blocking position by either the left lockout button or the right lockout button. 
     Optionally, the barrier and the switch may have complementary surfaces, which are shaped to maximize surface contact between the barrier and the switch when the barrier is in the blocking position. The switch may have a generally conical surface, with the barrier having a generally inverted conical surface. The barrier will generally return back into the blocking position after a small movement away from the blocking position because of the complementary surfaces. 
     In another embodiment, the first lockout button is pivotably movable around a pivot mount near the first side of the handle body. In some embodiments, the barrier may be fixed to the first lockout button so that a pivotal movement of the first lockout button results in a movement of the barrier away from the blocking position. 
     In other embodiments, the second lockout button may also be pivotably movable around a pivot mount near the second side of the handle body. In such embodiments, the barrier may also be movable away from the blocking position by pivoting of the second lockout button, since the second lockout button and the first lockout button are operably linked. Optionally, the operable link between the first lockout button and the second lockout button may be a linkage. 
     Optionally, in some embodiments, the first lockout button may have at least one finger extending outwardly, adapted for contacting the spring. When the barrier (mechanically coupled to the first lockout button) is moved away from the blocking position, the finger of the first lockout button is effective for compressing the spring. 
     As will be recognized by those of skill in the art, in many embodiments, it is convenient to refer to “the first side and the second side” as “the left side and the right side”, although it is not necessary to the present invention that the first side and the second side be assigned to a particular direction or handedness. For example, the first side might also be called the “right side” and the second side might be called the “left side.” The first side could be called “the top side” and the second side might be called “the bottom side.” All that is required for the present invention is a handle body with both a first side and a second side. 
     In another embodiment, the present invention is also directed to an ambidextrous switch lockout system. The system is for use with a handle body with a first side and a second side, and the system includes a switch, a first lockout button having a protrusion and a barrier, a second lockout button having a protrusion, and a spring. The switch is mounted to the handle body, extends outwardly from the handle body, and is actuatable by an activating movement, which might be an inward, squeezing movement when the switch is a switch trigger or lever. 
     In such an ambidextrous switch lockout system, the first and second lockout buttons are pivotably mounted to the handle body. The protrusion of the first lockout button protrudes from the first side of the handle body, and the protrusion of the second lockout button protrudes from the second side of the handle body. The barrier of the first lockout button is adapted to prevent the activating movement of the switch (and hence, the actuation of the switch), by physically blocking the activating movement when the barrier is in a blocking position. The barrier is, however, movable from the blocking position by pressing of both the first lockout button and the second lockout button. When pressed, the first lockout button pivots the barrier away from the blocking position in a first direction, and the second lockout button pivots the barrier away from the blocking position in a second direction. The second lockout button and the first lockout button may also be operably linked, so that the movement of the second lockout button results in movement of the barrier, which, in an embodiment, is part of the first lockout button. As will be recognized by those of skill in the art, in other embodiments, the barrier may be part of the second lockout button. In any embodiment, the spring mounted to the handle body is mechanically coupled to the barrier, so that the barrier is biased toward the blocking position. 
     As described in connection with another embodiment of the present invention, the barrier and the switch may optionally have complementary surfaces shaped to maximize surface contact between the barrier and the switch when the barrier is in the blocking position. 
     The first lockout button may, in some embodiments, also include at least one finger extending outwardly for contacting the spring. When the first lockout button is moved, the finger compresses the spring. Since the barrier is connected with the first lockout button, the spring is capable of moving the barrier toward the blocking position. 
     In another embodiment, the blocking position is associated with a defined starting angle for the first lockout button. Pressing the protrusion from the first lockout button pivots the first lockout button away from the starting angle in either a first direction or a second direction. When the first lockout button is within a first angle in the first direction or a second angle in the second direction, the activating movement of the switch is prevented. However, when the first lockout button is moved beyond the first angle in the first direction away from the starting angle or the second angle in the second direction away from the starting angle, the activating movement of the switch becomes possible. In such an embodiment, the spring is effective for restoring the first lockout button to the starting angle, where the spring is in a minimally compressed state. 
     As will be recognized by those of ordinary skill in the art, it is not necessary to the present invention that the first lockout button or the second lockout button be pivotally mounted to the handle body. In other embodiments of the present invention, the first lockout button or the second lockout button may be slidably mounted to the handle body. In such embodiments, the blocking position of the barrier may not be defined by a starting angle, since the barrier need not move pivotally in every embodiment. In another embodiment, the blocking position may be defined with reference to another portion of the device. All that is necessary to the invention is that the barrier block the activating movement of the switch 
     In yet another embodiment, the present invention provides an ambidextrous lockout switch system for use in a handle body including a switch, a means for blocking, at least two means for selectively moving the means for blocking, and a means for biasing. The switch is generally actuatable by an activating movement. The means for blocking is used to block the activating movement when the means for blocking is in a blocking position. The means for biasing provides a force for restoring the means for blocking to the blocking position. 
     In some embodiments, the at least two means for selectively moving are a first lockout button and a second lockout button, the first lockout button and the second lockout button being operably linked. Optionally, the second lockout button may be operably linked to the first lockout button by a linkage. Also optional (as explained above) is an embodiment in which the first lockout button is pivotably mounted to a first side of the handle body and the second lockout button is pivotably mounted to a second side of the handle body. The means for blocking may be fixed to either the first or the second lockout button, so that the means for blocking is movable away from the blocking position with either the first lockout button or the second lockout button. In some optional embodiments, at least one finger may extend outwardly toward the means for biasing from one of the at least two means for selectively moving. In such an embodiment, the at least one finger is adapted for contacting the means for biasing. Finally, the means for biasing may be a spring mounted inside the handle body and mechanically coupled to the at least two means for selectively moving. Other means for biasing, such as an plastic flap or rubber band are possible. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other objects, advantages, and features of the present invention will be apparent from the following detailed description and the accompanying drawings, in which: 
     FIG. 1 is a perspective view of an ambidextrous lockout switch, in accordance with an embodiment of the present invention; 
     FIG. 2 is a side elevation view of an ambidextrous lockout switch, in accordance with an embodiment of the present invention; 
     FIG. 3 is a cross-sectional view of an empty handle body for a power tool, in accordance with an embodiment of the present invention; 
     FIG. 4 a  is a cross-sectional view of a left lockout button and a barrier in a blocking position, in accordance with an embodiment of the present invention; 
     FIG. 4 b  is a cross-sectional view of a left lockout button and a barrier moved rightwardly away from a blocking position, in accordance with an embodiment of the present invention; 
     FIG. 4 c  is a cross-sectional view of a left lockout button and a barrier moved leftwardly away from a blocking position, in accordance with an embodiment of the present invention; 
     FIG. 5 is a cross-sectional view of an ambidextrous lockout switch, with a barrier in a blocking position, in accordance with an embodiment of the present invention; 
     FIG. 6 is a cross-sectional view of an ambidextrous lockout switch, with a barrier moved rightwardly, away from a blocking position, in accordance with an embodiment of the present invention; 
     FIG. 7 is a cross-section view of an ambidextrous lockout switch, with a barrier moved leftwardly, away from a blocking position, in accordance with an embodiment of the present invention; and 
     FIG. 8 is an exploded view of an ambidextrous lockout switch, in accordance with an embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Power tools, such as miter saws, may optionally include a selectively rotatable handle, for orienting the body of the handle horizontally, vertically, or intermediately between a horizontal position and a vertical position. In some orientations of the handle body, the mechanism for activating the tool may not be convenient for use with either a left hand or a right hand. The ambidextrous lockout switch system of the present invention advantageously allows for a user of a tool incorporating the system to activate the tool with either a left hand or a right hand in substantially the same way, even as the handle body is oriented in a plurality of different positions. 
     A perspective view of an embodiment of an ambidextrous switch lockout system  10  for a power tool, in accordance with the present invention, is shown in FIG.  1 . The handle body  40  includes a handle bottom  42 , a handle top  44 , and a collar mount  80 . Protruding from a left side  20  and a right side  30  of the handle body  40  are a left lockout button  60  and a right lockout button  70 . 
     In an embodiment, the handle body  40  of the present invention has a bi-level shape. A side-elevation view of the handle  10  from the right is shown in FIG. 2. A cross-sectional plane extending into the plane of the page is shown bisecting the handle body  40  generally along a line I—I in FIG.  2 . Since the side view is from the right, the right lockout button  70  is visible, along with the handle bottom  42 , the handle top  44 , and the collar mount  80 . 
     The handle bottom  42  provides a structural base for mounting of the other parts of the present invention. A cross-sectional view from above of the empty handle bottom  42  is shown in FIG.  3 . The cross-section is taken generally along the cross-sectional plane shown as the line I—I in FIG.  2 . The empty handle bottom  42  has a plurality of spacers  310  for connecting the handle bottom  42  with the handle top  44 . In addition there are pivot mounts  360  for the left side  20  and right side  30  of the handle bottom  42 . The contact mounts  370  are provided for mounting of the switch box ( 540  in FIGS.  5 - 8 ). The switch lever pivot mount  340  provides a pivotal mount for the switch lever ( 410  in FIGS.  4 - 8 ). The spring mount  300  provides a slot for housing the spring ( 460  in FIG.  4 ). In an embodiment, the handle bottom  42  itself is molded plastic. 
     Advantageously, two separate movements are required for activation of a tool incorporating the ambidextrous switch lockout system. FIG. 4 illustrates how, in an embodiment, the blocking mechanism  400  of the present invention requires two separate movements for activation. Basic structures of the blocking mechanism  400  are the switch lever  410  and barrier  405 . According to an embodiment of the present invention, the barrier  405  blocks the switch lever  410  in a blocking position, as shown in FIG. 4A, and allows for the switch lever  410  to be actuated when it is moved either rightwardly (as in FIG. 4B) or leftwardly (as in FIG. 4C) away from the blocking position in FIG.  4 A. 
     Referring to FIG. 4A, there is shown the barrier  405  in a blocking position. Note that the end of the barrier  405  nearest the switch lever  410  is shaped with a surface complementary to that of the end of the switch lever  410  nearest the barrier  405 . The respective surfaces are shaped so as to maximize contact when the barrier  405  is in the blocking position. In an embodiment, the complementary surface of the barrier  405  is generally inverted conical, and the switch  410  is generally conical where the two surfaces are in contact in the blocking position. 
     The barrier  405  is fixed to the left lockout button  60  by a left joining piece  62 . Also connected to the left joining piece  62  is a finger mount  440 , to which a left finger  420  and a right finger  430  are mounted. The fingers  420  and  430  extend outwardly from the finger mount  440  to contact the spring  460 . The finger  420  effectively compresses the spring  460  when the barrier  405  is moved rightwardly, as in FIG.  4 B. The finger  430  effectively compresses the spring  460  when the barrier  405  is moved leftwardly, as in FIG.  4 C. 
     The left lockout button  60  is movably mounted to the handle body  40  at the pivot mount  360 . A portion of the left lockout button extends toward the left side on the page in FIG. 4; this portion is also called a protrusion since the portion protrudes from the left side  20  of the handle body  40  (see FIG.  1 ). Pressing of the protrusion by the thumb of a right hand of a user results in a pivoting movement of the left lockout button  60 , left joining piece  62 , and barrier  405 . In the pivoting movement initiated by pressing of the protrusion of the left lockout button  60 , the left lockout button  60  moves rightwardly while the barrier  405  moves leftwardly, eventually resulting in the position shown in FIG.  4 C. When the right lockout button  70  (not shown in FIG. 4) is pressed, an operable link between the right lockout button  70  and the left lockout button  60  results in a second pivoting movement of the left lockout button  60 . In the pivoting movement initiated by the pressing of the right lockout button  70 , the left lockout button  60  moves leftwardly while the barrier  405  moves rightwardly, eventually resulting in the position shown in FIG.  4 B. As shown by FIGS. 4B and 4C, the switch lever  410  is able to move with an inward movement when the barrier  405  has been moved away (either leftwardly or rightwardly) from the blocking position shown in FIG.  4 A. However, when the barrier  405  is moved only slightly, the complementary surfaces of the barrier  405  and the switch lever  410  bias the blocking mechanism  400  back toward the position shown in FIG.  4 A. 
     Also shown in FIG. 4 is the mechanical coupling between the spring  460  and the barrier  405 . As shown in FIG. 4B, when the barrier  405  is moved rightwardly, the spring  460  is compressed by the left finger  420  of the finger mount  440 . When the barrier  405  is moved leftwardly, as in FIG. 4C, the spring  460  is compressed by the right finger  420  of the finger mount  440 . In each case, the energy stored in the spring with movement of the barrier  405  biases the barrier  405  back toward the blocking position (shown in FIG.  4 A), wherein the spring is at equilibrium (but not necessarily uncompressed, depending on the size of the spring mount  300 ). The spring  460  is also called a “centering spring” because the spring  460  biases the barrier  405  toward the blocking position regardless of whether the barrier  405  has been moved rightwardly (as in FIG. 4B) or leftwardly (as in FIG.  4 C). 
     In an embodiment, the parts of the invention shown in FIG. 4 fit together with an empty handle body as shown in FIG. 5. A cross-sectional view of the complete handle body  40  taken generally along the line I—I (from FIG. 2) is provided in FIG.  5 . In particular, FIG. 5 provides a more complete view of the switch lever  410 , only the left portion of which is visible in FIG.  4 . As is apparent from the embodiment shown in FIG. 5, the switch lever  410  extends along most of the length of the handle body  40 . When the barrier  405  is away from the blocking position, the switch lever may be actuated by an inward, squeezing movement of the fingers of either a left hand or a right hand. As the switch lever  410  is squeezed inwardly, the contact  530  is pivoted into an activated position, powering the tool for which the ambidextrous lockout switch  10  is used. The switch lever  410  pivots around the switch lever mount  340 . 
     In FIG. 5, the barrier  405  is in the blocking position (compare with the close up of the blocking mechanism  400  in FIG.  4 A). The left lockout button  60 , left joining piece  62 , finger mount  440 , and barrier  405  all appear as in FIG.  4 . However, a linkage  520  is shown in FIG.  5 . The linkage  520  operably links the left lockout button  60  to the right lockout button  70  by mechanically coupling the left joining piece  62  to the right joining piece  72  so that a pivotal movement of either the left lockout button  60  or the right lockout button  70  will result in a pivotal movement of both. 
     Pressing of the right lockout button  70  results in pivoting of the right lockout button  70  and the right joining piece  72  around the pivot mount  360 , in substantially the same way as the pressing of the left lockout button  60  results in pivoting of the left lockout button  60  and the left joining piece  62  around the pivot mount  360  near the left side of the handle  10 . Because the pivot mount  360  is between the respective lockout buttons and their corresponding joining piece, pivoting of a lockout button in one direction results in a pivoting of the respective joining piece in the opposite direction. 
     FIG. 6 shows an embodiment of the ambidextrous switch lockout system in which the right lockout button  70  has been pressed by the thumb of a left hand. Pressing of the right lockout button  70  with the thumb of a left hand results in leftward pivoting of the right lockout button  70  and rightward pivoting of the right joining piece  72 . As the right joining piece  72  pivots rightwardly, the linkage  520  is shifted rightwardly along with the right joining piece  72 , and the left joining piece  62 , being hingedly connected to the linkage  520  is also shifted rightwardly. The barrier  405 , being fixed to the left joining piece  62 , is thus also shifted rightwardly, so that the barrier  405  is finally moved from the blocking position and the switch lever  410  is inwardly movable (and has already been moved inwardly in FIG.  6 ), pivoting the contact  530  as it moves inwardly, and activating a tool for which the ambidextrous lockout switch  10  is used. 
     FIG. 4B is simply a cross-sectional view of the blocking mechanism in the position shown in FIG.  6 . Referring to FIG. 4B, there is shown how the barrier  405  is biased back towards the blocking position (shown in FIGS.  4 A and  5 ). Once the barrier  405  has been pivoted rightwardly, the spring  460  compresses. When the switch lever is released, the contact  530 , which, in an embodiment, also contains a contact spring, pushes the switch lever  410  back, and the spring  460  then pushes the barrier  405  back into the blocking position. 
     The ambidextrous lockout switch  10  shown in FIG. 7 is an embodiment in which the left lockout button  60  has been pressed by the thumb of a right hand, pivoting the barrier  405  leftwardly away from the blocking position. The switch lever  410  is then free to be moved inwardly, pushing the contact  530  and activating a tool with which the ambidextrous lockout switch  10  is used. 
     A three-dimensional exploded view of the ambidextrous lockout switch system  10  is shown in FIG.  8 . The handle body  40  includes a handle bottom  42  and handle top  44 . The switch lever  410  is hingedly connected to the handle bottom  42  at the switch lever pivot mount  340 . The contact  530  includes, in an embodiment, two layers, and is pivotally connected to the handle bottom  42  by the contact mounts  370 . The contact  530  is mounted to the handle bottom  42  near the switch box  540  (also shown in FIGS.  5 - 7 ), The switch box  540  has power and control cables (shown in FIGS. 5-7) for connecting with a power tool through the collar mount  80 . The linkage  520  operably links the left lockout button  60  and the right lockout button  70 , which are mounted to the pivot mounts  360  on the left side  20  and the right side  30  of the handle bottom  42 . 
     All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
     The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
     Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Of course, variations of those preferred embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.