Games controller and trigger therefor

Description of equivalent WO 2017089820 A2

GAMES CONTROLLER AND TRIGGER THEREFOR

TECHNICAL FIELD

0003The invention relates to controllers for controlling the play of computerised games and to a trigger mechanism for a games controller. More particularly, but not exclusively, the invention relates to an adjustable actuator system, such as a trigger button, of a game controller for a gaming console and to a method of adjusting the range of travel of an actuator. BACKGROUND

0004There are many different types of gaming consoles currently available for operating a video game. For example, Microsoft®, Sony® and Nintendo® manufacture the Xbox®, PlayStation® and Wii® gaming consoles, respectively. The gaming consoles typically include a game controller so that a user can control the operation of the video game.

0005Some known game controllers include a form of actuator system for the operation of control of the functions of the video games. Actuators, buttons or other depressible or manually operable devices are typically used for controlling discrete actions such as the firing of a weapon or an attack command. It is known to provide a button or actuator which is intended to be operable by the index finger of a user; such buttons are commonly known as triggers.

0006At times, dependent upon the video game being played, it can be necessary to depress the trigger a distance before the trigger initiation point is reached and the command actually acknowledged. This renders part of the depressing action futile. Likewise, after the command has been operated, it is often possible to carry out further depression of the trigger past the trigger initiation point. This further depression is unnecessary and may also be disadvantageous.

0007Furthermore, in other situations in some video games, the strength of a command is increased or decreased dependent upon how frequently the trigger is depressed. As such, depressing the trigger the whole distance is unnecessary and excessive for the command or operation required.

0008It is desirable to have a controller, particularly for gaming applications, that is more responsive or has less scope for allowing unnecessary over-movement by the user of the controller. It is also desirable to provide a trigger mechanism which can be readily adjusted dependent upon the game being controlled to alter the degree of travel of the trigger mechanism.

0009Due to the rapidly expanding gaming market and development of involved games invoking considerable player input, it is desirable for players to be able to customise their controllers in order to gain increased control in a variety of gaming circumstances.

0010Games controllers may comprise a haptic feedback system such as a vibrating or rumble motor (an off-centered or eccentric weight attached to the rotational shaft of the motor that causes the motor to wobble or vibrate). Such a haptic feedback system may be mounted or disposed with the trigger body or chassis. It is an object of the present invention to provide an adjustable trigger mechanism which can accommodate a haptic feedback system.

0011The present invention seeks to improve upon or at least mitigate some of the problems associated with controllers of the prior art by providing a game controller, which includes an adjustable trigger system that has a mechanism to allow the end user to control or recalibrate the maximum and/or minimum trigger positions.

SUMMARY

0013There are a variety of different commands available for the trigger functions of a game controller, and the adjustable trigger system of the present invention now provides users with the option to customise the trigger settings to suit the individual game at the time of operation. In some embodiments the trigger system includes adjustments for the amount that the trigger is depressed before there is no more motion available to be made by the operator. This removes any unnecessary distance travelled by the trigger.

0014The present invention provides a method of controlling the amount of available motion of a trigger system dependent upon the gaming circumstances.

0015According to a first aspect of the invention, there is provided a trigger mechanism for a games controller for controlling electronic games, the trigger mechanism comprising:

0016a trigger body having a plurality of walls defining an internal chamber, the plurality of walls including a base wall and an orifice defined in the base wall;

0017a detent detachably mounted on the trigger body, the detent at least partially received in the orifice and wherein the detent is rotatable with respect to the trigger body; the detent comprising at least one abutment surface, eccentrically arranged with respect to the rotational axis of the detent.

0018Optionally, the detent comprises a push fitting for securing the detent to the trigger body.

0019Optionally, the detent is rotatable between a first position and a second position.

0020Optionally, in the first position the detent is stowed within the interior chamber of the trigger body.

0021Optionally, the detent comprises a pair of oppositely disposed trunnions receivable in a partial cylinder provided by a receiver disposed within the interior chamber.

0022Optionally, the detent comprises a pair of opposing surfaces.

0023Optionally, the detent is rotatable about an axis which extends through the base wall.

0024Optionally, the detent rotates about an axis substantially perpendicular to the plane of the base wall.

0025Optionally, the detent rotates about an axis extending substantially radially from an outer surface of the base wall.

0026Optionally, the detent is toollessly detachable from the trigger body.

0027Optionally, the at least one abutment surface is rotatable from a first position and a second position, the abutment surface being disposed in closer proximity to the rotational axis of the detent in the second position than in the first position. Optionally, a trigger mechanism comprises a face plate detachably mounted to the trigger body and wherein the detent is disposed behind the face plate.

0028According to a second aspect of the invention, there is provided an apparatus for supplying user inputs to a computer program, such as a game program, for controlling the game program, the apparatus comprising at least one depressible trigger mechanism, the trigger mechanism comprising a trigger body having a detent for manual adjustment of the depressible range of the trigger mechanism; the trigger body comprising a plurality of walls, including a base wall, the plurality of walls defining an interior chamber of the trigger body;

0029the base wall comprising an orifice for receiving at least in part the detent, the detent being detachably mounted to the trigger body and being rotatable with respect to the trigger body, the detent comprising at least one abutment surface eccentrically arranged with respect to the rotational axis of the detent.

0030Optionally, the detent is rotatable between a first position and a second position, the trigger mechanism being depressible through a first range when the detent is in the first position and through a second range when the detent is in the second position, the second range being shorter than the first range.

0031Optionally, the apparatus comprises a casing wherein rotation of the detent through 180 degrees rotates a first one of the abutment surfaces from a position facing towards the casing to a position facing away from the casing.

0032Optionally, the detent comprises a pair of opposed abutment surfaces.

0033Optionally, the apparatus is a hand held controller for a games console comprising an outer case, and a plurality of controls are located on a front and a top of the controller; the controller being shaped to be held in both hands of a user such that the user's thumbs are positioned to operate controls located on the front of the controller and the user's index fingers are positioned to operate controls located on the top of the controller. According to a third aspect of the invention, there is provided a trigger mechanism for a games controller for controlling electronic games, the trigger mechanism comprising:

0034a trigger body having a plurality of walls including a front wall, the plurality of walls defining an interior chamber of the trigger body, the front wall comprising an inner surface and an outer surface;

0035an actuator comprising a first component mounted on the inner surface of the front wall;

0036a bore extending from the outer surface of the front wall to the interior chamber and defining a bore within the first component coupled to a second component coupled to the first component and a screw thread for adjusting the position of the second component with respect to the first component. Optionally, the second component comprises an external screw thread and is rotatably mounted within the bore.

0037Optionally, the second component comprises a first end forming an abutment surface.

0038Optionally, the first component comprises an external thread and the second component comprises an internal thread which receives the external thread of the first component and the bore provides access to a screw drive enabling torque to be applied to the second component.

0039Optionally, the second component is in communication with a transducer, and wherein adjustment of the position of the second component with respect to the first component affects an electrical characteristic of the transducer. Optionally, the second component comprises an abutment surface for abutment with a transducer.

0040Optionally, the transducer is a pressure sensor. Optionally, the second component comprises a magnet for actuating a magnetic sensor.

0041Optionally, the second component is coupled to a potentiometer so as to adjust an electrical characteristic of the potentiometer. Optionally, the trigger mechanism further comprises a face plate detachably mounted to the trigger body, the face plate concealing the orifice in the front wall.

0042Optionally, there is provided an apparatus for supplying user inputs to a computer program, such as a game program, for controlling the game program, the apparatus comprising at least one depressible trigger mechanism.

0043Optionally, the apparatus further comprises the trigger mechanism.

0044Within the scope of this application it is envisaged and intended that the various aspects, embodiments, examples, features and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings may be taken independently or in any combination thereof. For example, features described in connection with one embodiment are applicable to all embodiments unless there is incompatibility of features.

BRIEF DESCRIPTION OF THE DRAWINGS

0046Exemplary embodiments of the invention will now be described with reference to the accompanying drawings, in which:

0047Figure 1 is a schematic illustration from above of the front of a games console controller according to the present invention;

0048Figures 2 and 3 are perspective views from below of the rear panel of a games console controller according to a first embodiment;

0049Figure 4 is an internal view of a trigger mechanism according to a first embodiment;

0050Figure 5 is a perspective view from below of a trigger mechanism according to a first embodiment;

0051Figure 6 is an exploded view of a trigger mechanism according to a first embodiment Figure 7 is a side view of a trigger mechanism according to a first embodiment in which a stop mechanism is in a second condition;

0052Figure 8 is a side view of a trigger mechanism according to a first embodiment in which a stop mechanism is in the first condition;

0053Figure 9 is a perspective view from below of the rear panel of a games console controller according to a second embodiment;

0054Figures 10 and 1 1 are perspective views from below of a trigger mechanism according to the second embodiment; and

0055Figure 12 is an internal view of the trigger mechanism of Figures 10 and 1 1 . DETAILED DESCRIPTION OF THE EMBODIMENTS

0056Detailed descriptions of specific embodiments of the games controller and its trigger mechanism are disclosed herein. It will be understood that the disclosed embodiments are merely examples of the way in which certain aspects of the invention can be implemented and do not represent an exhaustive list of all of the ways the invention may be embodied. Indeed, it will be understood that the games controller and its trigger mechanism described herein may be embodied in various and alternative forms. The Figures are not necessarily to scale and some features may be exaggerated or minimised to show details of particular components. Well-known components, materials or methods are not necessarily described in great detail in order to avoid obscuring the present disclosure. Any specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the invention. Referring to Figures 1 and 2 there is shown a controller 1 according to an embodiment of the present invention. Figure 1 shows the controls which are mounted on the front and Figure 2 shows the controls mounted on the top of the controller 1 . Specifically, the front of the controller 1 is provided with left and right analogue thumb sticks 2, 3 which normally control movement and are intended to be operated by the user's left and right thumbs respectively. There are four buttons 4, located on a forward-right portion of the controller 1 , which normally control additional actions and are intended to be operated by the user's right thumb. There is a direction pad 5 located on a forward-left portion of the front of the controller 1 . The direction pad 5 is intended to be operated by the user's left thumb, typically either as an alternative to the left thumb stick 2 or to provide additional actions. There are a left trigger 6, a right trigger 7, a left bumper 8 and a right bumper 9 located on the front of the controller 1 , see Figure 2. The left and right triggers 6, 7 are typically operated by a user's index fingers. The left and right bumpers 8, 9 may also be operated by a user's index fingers.

0057Figure 2 illustrates a back of the controller 1 . Two paddle levers 1 1 A, 1 1 B, are mounted to the back of the controller 1 . The paddle levers 1 1 A, 1 1 B are configured to replicate the function of one or more of the controls provided upon the front of the controller 1 . The paddle levers 1 1 A, 1 1 B are mounted to a housing 12 by a mechanical fixing.

0058The housing 12 defines a pair of handles H1 , H2 which a user may grasp when operating the controller 1 . The paddle levers 1 1 A, 1 1 B are configured to be operated by a middle finger of an operator which is wrapped around the handles H1 , H2.

0059Figure 3 illustrates a back panel 14 of the controller; the back panel 14 forms a part of the body or housing 12 of the controller 1 . The housing 12 comprises a pair of apertures A in a top edge thereof. The apertures may be defined entirely within the back panel 14 or in part in the back panel 14. An actuator, in the form of a trigger mechanism 6, extends through each aperture A; one of the trigger mechanisms has been omitted from Figure 3 for illustrative purposes. Figure 3 illustrates a left trigger mechanism 6 extending through one of the apertures A.

0060Figures 4 to 6 illustrate a trigger mechanism 6 for mounting in the apertures A of the housing 12. The Figures illustrate a left handed trigger mechanism; it will be appreciated that the right handed trigger mechanism is substantially the same in structure albeit a mirror image of that shown in Figures 4 to 6. The left and right trigger mechanisms 6, 7 will be described by reference to the left trigger mechanism 6.

0061The trigger mechanism 6 is movable through a predefined range of motion with respect to the housing 12.

0062The trigger mechanism 6 comprises a trigger body 18 which may be pivotally mounted to the housing 12; in the illustrated embodiment the trigger body is mounted to the back panel 14. The trigger mechanism 6 comprises a pair of trunnions 22 for pivotally mounting the trigger body 18 to the housing 12.

0063The trigger mechanism 6 comprises a sensor, not shown. The sensor may comprise a displacement transducer. The sensor may be analogue or digital in nature and arranged to measure a parameter indicative of the position of the trigger body 18 with respect to the housing 12 so as to sense or detect the position of the trigger body 18 with respect to the housing 12. For example, but not limited to, the sensor may take the form of: a potentiometer; a magnetic sensor; a Hall effect sensor; or a force or pressure sensitive switch or pad. The sensor is coupled to control electronics on a printed circuit board. The trigger mechanism 6 comprises an interchangeable face plate 20. The face plate 20 is mounted to the trigger body 18 by a mechanical fixing such as a snap or bayonet style fitting.

0064The trigger mechanism 6 comprises a hair trigger mechanism for adjusting the start position or rest position of the trigger body 18 with respect to the back panel 14.

0065The trigger body 18 comprises a shaft 30 extending from an inner face of the trigger body 18. An orifice or bore 32 extends through the shaft 30 from a front surface of the trigger body 18 to the interior of the trigger body 18. The face plate 20, when mounted to the trigger body 18, conceals or covers the orifice 32.

0066The shaft 30 comprises a pair of parallel keys 31 which mate with keyways in a cap 24. The cap 24 comprises an orifice or blind hole (not shown) for receiving the shaft 30. In alternative embodiments the shaft 30 may comprise one or more keys 31 or keyways or may comprise a spline. The keys 31 prevent rotation of the cap 24 when mounted upon the shaft 30. A screw (not shown) is mounted into the bore 32 of the shaft 30. The bore 32 may comprise an internal screw thread. In alternative embodiments the screw may be a self-tapping screw and may cut into the side wall of the bore 32. Optionally the screw is a grub screw. The screw can be adjusted to bear against an interior face of the cap 24. In this way the position of the cap 24, with respect to the inner face of the trigger body 18, can be adjusted. The cap 24 is translationally or slideably mounted upon the shaft 30.

0067In use the pressure sensitive switch is disposed such that the cap 24 cannot be unintentionally dislodged from the shaft 30. However, in alternative embodiments, the cap 24 and shaft 30 may comprise an end stop which prevents the cap detaching from the shaft 30.

0068For example, the cylindrical wall of the cap 24 may comprise a bore extending therethrough.

0069A second screw may be received in the bore and partially extend into the interior of the cap

007024. A channel may extend longitudinally along the shaft 30. The channel may be closed at a first end distal from the inner face to which the shaft 30 is mounted. The second screw may be received in the channel thereby preventing rotation of the cap 24 with respect to the shaft

007130. The closed end of the channel forms an end stop preventing separation of the cap 24 from the shaft 30. The cap 24 comprises a projection 25 in the form of a rib which defines a contact surface which bears against the pressure sensitive switch.

0072The cap 24 and shaft 30 form a telescopic arrangement which can be extended and retracted so as to adjust the distance between the contact surface and the inner face of the trigger body 18.

0073The trigger mechanism 6 comprises a resilient biasing mechanism. The resilient biasing mechanism may take the form of a spring mounted between the trigger mechanism 6 and the controller housing 12. The spring biases the trigger body 18 to a start or rest position. In alternative embodiments, the resilient biasing mechanism may be incorporated, or integral, with the pressure sensitive switch and arranged such that when the pressure sensitive switch returns to its unbiased or relaxed condition the trigger body 18 is returned to the start or rest position. In embodiments employing a force or pressure sensitive switch, the hair trigger mechanism may be adjusted such that the cap 24 bears against the pressure sensitive switch and at least partially depresses or activates the pressure sensitive switch. In this way the trigger mechanism applies preload (an adjustable degree of pressure or force) to the pressure sensitive switch. In applications which require a preset magnitude of pressure or force to be applied to the pressure sensitive switch in order to initiate a command instruction, the degree of movement of the trigger body 18 necessary to initiate the command instruction is reduced. In this way the latency of the trigger mechanism 6 is reduced.

0074In embodiments employing a potentiometer, the start or rest position of a sliding contact or wiper with respect to a resistive element, with which it is in electrical contact, is adjusted. In embodiments employing a magnetic sensor such as a Hall effect sensor, a magnetic sensor can be mounted or integrally formed with the cap 24. The location of the cap 24 with respect to the magnetic sensor can be adjusted so as to reduce the latency in the trigger movement. The trigger mechanism 6 comprises an adjustable stop mechanism 16. The adjustable stop mechanism 16 provides an adjustable end stop for limiting the range of motion of the trigger body 18. The adjustable stop mechanism 16 defines the maximum displacement or depression of the trigger body 18 with respect to the back panel 14. The adjustable stop mechanism 16 allows manual adjustment of the depressible range of the trigger mechanism 6.

0075The trigger body 18 comprises a base wall 19. The base wall 19 comprises an aperture A1 . The adjustable stop mechanism 16 comprises a detent 17 and a rotational mount 28. The rotational mount 28 comprises a snap or push fitting including two opposed barbs. The detent 17 extends or projects downwardly from the base wall 19 of the trigger body 18.

0076The detent 17 comprises a pair of opposed surfaces F1 , F2 each of which may arrest the travel of the trigger mechanism 6. The detent 17 is disposed eccentrically or off-centre. The detent 17 is rotatable between a first, stowed, position shown in Figure 8 and a second, deployed, position shown in Figure 7. The range of motion or degree of travel of the trigger mechanism 6 can be adjusted by rotating the detent 17 between the first and second positions. In the first position, the second surface F2 faces or opposes the back panel 14. When the trigger mechanism 6 is depressed sufficiently the second surface F2 is brought into contact with a portion of the back panel 14 thereby arresting the motion of the trigger mechanism 6. In the first position, the trigger mechanism 6 is moveable through a range of travel 'y'.

0077In the second position, the first surface F1 faces or opposes the back panel 14. When the trigger mechanism 6 is depressed sufficiently the first surface F1 is brought into contact with a portion of the back panel 14 thereby arresting the motion of the trigger mechanism 6. In the second position, the trigger mechanism 6 is moveable through a range of travel 'x'.

0078The range of travel 'y' is greater than the range of travel 'x'.

0079The detent 17 is rotatable about an axis extending substantially radially or perpendicularly from the base wall 19 of the trigger body 18, as shown in Figure 5.

0080In some embodiments, the detent 17 is detachable; this may allow a greater or larger range of travel of the trigger mechanism 6.

0081Referring now to Figures 9 to 12, there is shown an alternative embodiment of the present invention. In the second illustrated embodiment like numerals have, where possible, been used to denote like parts, albeit with the addition of the prefix "100" to indicate that these features belong to the second embodiment. The alternative embodiment shares many common features with the first embodiment and therefore only the differences from the embodiment illustrated in Figures 1 to 8 will be described in any greater detail.

0082The controller 101 of the second embodiment comprises an elongated face plate 120. The face plate 120 is detachably mounted to a trigger body 1 18.

0083The trigger mechanism 106 comprises an adjustable stop mechanism 1 16. The adjustable stop mechanism 1 16 provides an adjustable end stop for limiting the range of motion of the trigger body 1 18. The adjustable stop mechanism 1 16 defines the maximum displacement or depression of the trigger body 1 18 with respect to the back panel 1 14. The adjustable stop mechanism 1 16 allows manual adjustment of the depressible range of the trigger mechanism 106.

0084The trigger body 1 18 comprises a base wall 1 19. The base wall 1 19 comprises a cutaway or slot S1 . The adjustable stop mechanism 1 16 comprises an elongated detent 1 17 and a rotational mount 128 in the form of a pair of second trunnions 142. The second trunnions 142 are locatable in a receiver 140 in the form of a partial cylinder. The rotational mount 128 comprises a snap or push fitting for holding the detent 1 17 in the receiver 140.

0085The detent 1 17 is rotatable between a retracted or stowed position, in which the detent 1 17 lies substantially within the interior of the trigger body 1 18, and a deployed position in which the detent 1 17 extends or projects downwardly from the base wall 1 19 of the trigger body 1 18.

0086The detent 1 17 comprises a contact surface which arrests the travel of the trigger mechanism 106. The detent 1 17 is disposed eccentrically or off-centre.

0087The detent 1 17 optionally comprises a retainer 144, which may take the form of a snap or push fitting, for retaining the detent 1 17 in the stowed position.

0088One advantage of the present invention is that it allows adjustments to be made to the trigger response; such adjustment could be customised to suit both the nature of the video game that is in use at the time of operation, and the skill of the operator. For example, in combat-style games involving a shooting function, it is often the case that after reaching or passing the command initiation point, no further commands are initiated. In such games further depression of the trigger mechanism 6, 106, and hence movement of the displacement transducer or sensor, serves no useful purpose. Therefore the adjustable stop mechanism 16, 1 16, which controls the degree of trigger depression, allows the operator to restrict the amount of travel available to the trigger body 18, 1 18 to one of the predefined degrees of travel provided by the adjustable stop mechanism 16, 1 16. The adjustable stop mechanism 16, 1 16, when employing face F1 or face F2, impedes the movement of the trigger body 18, 1 18 by striking the housing 12.

0089Such an adjustment would directly relate to the majority of combat style games or other varieties of firing operations in video games. The faces F1 and F2 could find application in a variety of other video game genres but for the simplicity of this disclosure, reference is made to combat style games. In some other gaming styles, such as driving or flight simulations, the trigger buttons 6, 7 are employed for throttle control command function and/or a braking control command function. In this application, the degree of depression of the trigger body 18, 1 18 is detected by the displacement transducer. The degree of depression of the trigger body 18, 1 18 is converted into a signal, which signal directly relates to a command to be executed by the video game, for example the amount of acceleration or braking to be applied. In such games it may be desirable to be able to fully depress the trigger body 18, 1 18, for example when full depression corresponds to maximum throttle or maximum braking. Restricting travel of the trigger body 18, 1 18 would restrict the throttle control command function where the degree of travel of the trigger body 18, 1 18 is proportional to the speed of the vehicle of the simulation. In such gaming styles, the face F1 could be configured to allow full trigger depression. However, it will be appreciated that in such games it may be desirable to control the trigger response by adjustment of the adjustable stop mechanism 16, 1 16, to allow the operator to restrict the braking and accelerating functions of the game, for example restricting maximum throttle settings and braking level settings for difficult corners.

0090A further advantage of the present invention is that it minimises the amount of motion an operator's finger must travel, therefore minimising the recovery time after trigger initiation contacts have been made. This allows the operator to rapidly commence command prompt repeatedly, or to operate different commands more quickly. As the movement that is required to operate commands by depressing the trigger body 18, 1 18 is reduced to only that which is required, the risks of any related repetitive strain injury acquired due to the repeated movement of the finger when operating the trigger function would be greatly reduced thereby providing a health benefit to users. The present invention provides a readily adjustable device to restrict the range of movement of the trigger body 18, 1 18 to one of a plurality of predefined ranges. A further advantage of this embodiment is that the ergonomic design of the controller is not compromised.

0091Further, it will be appreciated that the adjustable stop mechanism 16, 1 16 can be removed from the trigger body 18, 1 18. A replacement adjustable stop mechanism 16, 1 16 can be inserted and secured. The replacement may provide additional or alternative predefined ranges of motion of the trigger body 18, 1 18. The adjustable stop mechanism 16, 1 16 may comprise faces which are game specific; that is to say, tailored to suit a particular game. Dependent upon the video game being played, it can be necessary to depress the trigger a distance before the trigger initiation point is reached and the command actually acknowledged. This initial movement of the trigger body is unnecessary and wasteful. Adjusting the start position is advantageous since it removes this unnecessary travel, thus reducing the time taken to initiate a command and thereby improving the responsiveness of the trigger. In combat style games, this can simulate a "hair-trigger" function. It can be appreciated that various changes may be made within the scope of the present invention. For example, in alternative embodiments, the cap 24 may be omitted. A screw (not shown) may be mounted within the bore 32 of the shaft 30. A first end of the screw may form an abutment surface which acts upon a transducer such as a pressure sensor.

0092In still other embodiments the cap 24 may comprise an internal screw thread and the shaft 30 may comprise an external screw thread matingly received in the internal screw thread. An inner face of the end wall of the cap 24 may comprise a screw drive such as a hex drive or torx drive or other suitable arrangement for application of torque to the cap 24.

0093In this way the cap 24 or the screw or both form a second part of a linear actuator, the shaft forming a first part of a linear actuator, the position of the second part with respect to the first part being manually adjustable so as to alter the linear dimension of the linear actuator. The linear actuator is in communication with a transducer or sensor which determines the position of the depressible trigger mechanism with respect to the housing of the controller.

0094It will be recognised that as used herein, directional references such as "top", "bottom", "front", "back", "end", "side", "inner", "outer", "upper" and "lower" do not limit the respective features to such orientation, but merely serve to distinguish these features from one another. While particular embodiments of the invention have been shown and described, numerous variations and alternate embodiments will occur to those skilled in the art without departing from the scope of the present invention.