Patent Publication Number: US-9409088-B2

Title: Trigger attachment and method for videogame controllers

Description:
FIELD OF THE DISCLOSURE 
     The disclosure relates to enhancements to triggers of videogame controllers used to play video games. More particularly, the disclosure relates to a trigger attachment and method for reducing trigger range of motion in videogame controllers. 
     BACKGROUND 
     Videogame controllers have become ubiquitous with contemporary versions of the hand-held controller being offered in a wide variety of multiple-trigger configurations. Several makes of videogame controllers have left and right trigger buttons positioned to be actuated by the user&#39;s index fingers when the controller is held by the user with two hands. Each trigger button has a predefined range of travel from the starting or zero position to the fully-depressed position. In games where trigger actuation is a binary function, the actuation point is generally about half way between the zero position and the fully-depressed position. Binary trigger button function is common in games where the trigger button controls shooting, jumping, or other movement. In such games, each manipulation of the trigger results in one shot, one jump, one turn, or other function operable on a yes/no basis. 
     In other games where the trigger produces an analog signal, the trigger button output signal changes based on the degree to which the trigger button is pressed. Such an analog response is used in games where the trigger button controls a throttle or other variable input device. 
     In games where rapid firing, jumping, running, or other action is required that are based on binary control from the trigger button, the gamer repeatedly presses the trigger in rapid succession. With ever-increasing computer power, the speed at which functions can be processed has also increased to the point where the gamer&#39;s speed in manipulating the trigger button is a limiting factor rather than the game&#39;s processing speed. Regardless of the controller configuration, users often fully press the trigger to its end point to implement binary control functions even though depression of about 50% would send the desired signal. However, since pressing the trigger to just past 50% in a fast and controlled manner is very difficult to do without a defined stopping point, the user very often fully presses the trigger despite not needing to do so. 
     Trigger buttons available on several popular videogame controllers have a range of motion that exceeds what is needed to cause the trigger button to signal a response in the game. Therefore, by eliminating or reducing unnecessary movement in the trigger before or after the point of signal, the gamer can speed up or economize trigger movement to improve game performance. 
     Referring to  FIGS. 1A and 1B , a side view illustrates one embodiment of a known videogame controller  10  having a controller housing  13  and a trigger  15 . Trigger  15  pivots about a pivot point  17  between a zero position  18  (shown in  FIG. 1A ) and a fully-depressed position or end position  19  (shown in  FIG. 1B ). A trigger range of motion  20  is defined as the travel of trigger  15  between the zero position  18  and the end position  19 . Within trigger range of motion  20  is an active zone  21  in which commands are initiated and carried out.  FIGS. 2A and 2B  illustrate a side view of another embodiment of a known controller  10 , also having housing  13 , and trigger  15  that pivots between zero position  18  (shown in  FIGS. 2A &amp; 2B ) and end position  19  (shown in FIG.  2 B) to define the trigger range of motion  20 . The take-up  23  of trigger  15  is the range of motion between zero position  18  and active zone  21 . The over travel  24  of trigger  15  is the range of motion between active zone  21  and end position  19 . 
     In some controllers,  10  trigger  15  abuts housing  13  to define zero position  18  and/or end position  19 ; in other controllers  10 , zero position  18  and end position  19  are defined by other structures (not shown) within housing  13 . Each trigger  15  of  FIGS. 1-2  has a trigger body  22  that extends partially from housing  13 , a finger contact surface  25  intended for contact with the user&#39;s finger (not shown), and a trigger tip  27 . 
     At least one attempt to address the trigger travel is disclosed in U.S. Pat. No. 8,480,491 (Jul. 9, 2013 to Burgess et al.). The &#39;491 patent is directed to a game controller having an adjustable trigger system for calibration or customized control of trigger action. The trigger has a strike plate coupled to a trigger body. Two adjustment screws extend through the controller housing to contact portions of the strike plate. By adjusting the screw positions, the trigger&#39;s range of travel is adjusted due to changing the point at which the screws make contact with the strike plate. 
     Burgess et al. also address trigger travel in a game controller in published PCT application no. WO 2015/004261 titled Games controller and Trigger Therefor. The &#39;261 publication discloses a game controller having a controller housing, a trigger body, a trigger housing, and a detent housing with at least one detent. The detent housing is rotationally mounted in the trigger body and is rotatable between a first position in which the detent is in a stowed condition and a second position in which the detent is in a deployed condition. When the detent is in deployed condition, the detent engages the controller housing to stop movement of the trigger body and limit the trigger movement. 
     Burgess et al. further address trigger range of motion in a game controller in published PCT application no. WO 2015/078994. The &#39;994 publication discloses a game controller including an adjustable trigger system with a mechanism to allow the end user to control or recalibrate the maximum and/or minimum trigger positions. When the trigger is pressed in typical game controllers, the trigger travels first through a “dead zone” where no commands are initiated. As the triggers is further depressed, it passes through an active region in which a command action is initiated and carried out. As the trigger is still further depressed beyond the active region, the trigger travels through an over travel zone to the trigger end stop during which no further commands are initiated. 
     The &#39;994 published PCT application addresses the problem of excessive trigger travel by modifying the internal structure of a trigger in a game controller to reduce the amount of “dead zone” at the beginning of the trigger pull and the “over travel” zone at the end of the trigger pull. The trigger body includes a limb extending back towards the housing. A front edge on the base housing defines an end stop to limit movement of the trigger. An arm is connected to a base plate in the controller housing and extends between the rear edge of the limb and the base housing. The front edge of the arm has an adjustable position and defines the end point of trigger travel. A control screw extends through the arm to a variable extent. As the control screw is advanced, the end of the screw comes into contact with the upper surface of the limb as the trigger pivots towards the start position. Thus, by adjusting the control screw, the trigger can be prevented from returning fully to the start position. By also adjusting the position of the arm, the end point of the trigger travel can also be altered. 
     SUMMARY 
     In the prior art approaches to trigger action discussed above, the trigger assembly is modified to include screws, detents, or other features that the user may advance, retract, or adjust to change the stop points of the trigger and therefore the trigger range of motion. As in the &#39;261 published PCT application, the trigger button is modified to include an adjustable detent that also changes the stop point of trigger travel. These approaches to optimizing trigger travel require purchasing a controller already equipped with these features or modifying existing controller features. 
     Purchasing new controllers is expensive and not all game systems may offer the modified trigger. Further, since price is a key consideration in a purchasing decision, the added cost of the modified trigger likely deters a purchase except for the most enthusiastic gamers. Therefore, the commercial viability of such a controller is questionable. 
     Modifying existing controllers requires that the controller be manufactured in a way that permits the user to access to the trigger assembly within the housing and also configured to accommodate such structural changes. Also, the user must have the skill, tools, and desire to perform the modification. Further, making adjustments to the trigger action can be time consuming, difficult to get right, and difficult to reproduce when returning the trigger action to a desired state after making changes for another game. 
     A further limitation of the approaches of Burgess et al. is that the trigger adjustments and modifications are particular to one controller. As such, the gamer&#39;s modified controller must be brought to the location where games are being played. More likely, the inconvenience of modifying the controller would result in the need to own several controllers each customized to a particular game. 
     Therefore what is needed is a different solution to the problem of excess trigger range of motion. The present invention is directed to a trigger attachment that can be installed on existing controller triggers to modulate the trigger range of motion without the need for any modification to the structure of the trigger itself. When installed on a stock trigger as supplied by the manufacturer, trigger attachments of the present invention continue to permit the trigger to initiate and carry out the desired commands in the game being played while also reducing excess trigger range of motion. 
     One aspect of the present invention is directed to a trigger attachment for a game controller to modulate the trigger range of motion. Embodiments of the trigger attachment reduce the trigger range of motion by making contact with the controller housing as the trigger is pulled and/or when the trigger is released from a depressed position. Trigger attachments installed on the trigger reduce the pre-travel (often called “take-up”) of the trigger to shorten the range of motion needed to activate the trigger function. With the trigger attachment installed, the trigger is prevented from returning fully to the zero position. Therefore, the trigger is closer to the actuation point compared to position of the trigger when it returns fully to the zero position as supplied by the controller manufacturer. The pre-travel is the distance the trigger button travels at the beginning of actuation before the trigger button reaches the activation point. Trigger attachments installed on the trigger alternately or additionally reduce the trigger over travel beyond the active zone. By making contact with the controller housing, the trigger attachment prevents the trigger from being pressed to the end of the full trigger range of motion. Trigger attachments of the present invention reduce the trigger range of motion, but permit cycles of activation and deactivation so as not to compromise trigger function. 
     In one aspect of the invention, a trigger attachment is for use with a game controller having a housing, a trigger extending through the housing with a finger contact surface and operable through a trigger range of motion between a zero position and an end position. In one embodiment the trigger attachment has an attachment body defining a recess with a receiving face shaped to mate with the finger contact surface of the trigger, a sloped outer front surface, and a lower housing contact surface. The attachment body is sized and shaped to be mounted on the trigger with the trigger partially received in the recess and the receiving face against the finger contact surface of the trigger. When mounted on the trigger, the lower housing contact surface is positioned to abut the housing when the trigger is pressed, thereby reducing the trigger range of motion by preventing the trigger from fully achieving the end position. 
     In another embodiment, the attachment body further defines an upper housing contact surface shaped and configured to reduce a take-up portion of the trigger range of motion by contacting the housing and preventing the trigger from returning fully to the zero position. 
     In another embodiment, the trigger attachment attaches to the trigger using a friction fit. In another embodiment, the attachment body defines at least one catch and the friction fit includes the catch(es) engaging a void or catch surface on the trigger. In another embodiment, the friction fit includes the attachment body engaging the finger contact surface and sides of the trigger. 
     In another embodiment, the trigger attachment also includes an upper catch and a lower catch to retain the trigger attachment on the trigger. For example, the upper catch extends from the trigger body and is configured engage a top trigger surface. The lower catch extends from the trigger body and is positioned to engage a lower trigger surface. 
     In some embodiments, an adhesive is used to secure the trigger attachment to the trigger. For example, adhesive is disposed on the receiving face of the trigger attachment. 
     In another embodiment, the trigger attachment includes a mounting bracket sized to be mounted on the finger contact surface of the trigger. The mounting bracket defines at least one bracket catch surface. The attachment body mates with the mounting bracket and engages the bracket catch surface(s) to removably retain the attachment body on the mounting bracket and therefore on the trigger. In some embodiments, the attachment body engages the mounting bracket with a snap fit. In other embodiments, attachment body slidingly engages the mounting bracket. 
     In another embodiment, the mounting bracket or the trigger attachment includes a magnet and the other of the trigger attachment and the mounting bracket includes a ferromagnetic material. Magnetic attraction between the magnet and the ferromagnetic material is sufficient to retain the trigger attachment coupled to the trigger during normal use of the controller. 
     In another embodiment, the trigger attachment includes a wedge member that can be inserted between a top surface of the trigger and the housing. The wedge member prevents the trigger from returning fully to the zero position. The wedge member “pre-primes” the trigger for quicker activation by reducing the take-up portion of the trigger range of motion, yet without compromising the cyclical activate-deactivate function of the trigger. 
     In another embodiment, the sloped outer front surface is concavely curved down along and forward from the trigger to engage a user finger. This curvature increases the leverage of the user finger to actuate the trigger when the finger engages the trigger attachment. For example, the concave shape of the sloped outer front surface is contoured to the shape of a human finger to provide enhanced tactile feel and to provide an enhanced resting surface for the finger when the trigger is not being activated. 
     Another aspect of the invention is directed to a method of reducing trigger range of motion in a video game controller. In one embodiment, the method includes the steps of providing a video game controller having a housing, a trigger extending through the housing with a finger contact surface and operable through a trigger range of motion between a zero position and an end position; providing a trigger attachment having an attachment body defining a recess with a receiving face shaped to mate with the finger contact surface of the trigger, an sloped outer front surface, and a lower housing contact surface; mounting the trigger attachment on the trigger with the trigger partially received in the recess and the receiving face against the finger contact surface of the trigger; and positioning the lower housing contact surface to abut the housing when the trigger is pressed, thereby reducing the trigger range of motion by preventing the trigger from fully achieving the end position. 
     In another embodiment of the method, the step of mounting the trigger attachment on the trigger includes applying an adhesive between the trigger attachment and the trigger. 
     In another embodiment of the method, the step of mounting the trigger attachment on the trigger includes providing a mounting bracket, securing the mounting bracket to the contact surface of the trigger, and installing the trigger attachment on the trigger by mating engagement with the mounting bracket. 
     In one embodiment of the method, the step of mounting the trigger attachment on the trigger includes inserting the trigger partially into the recess, positioning the receiving face to abut the finger contact surface of the trigger, and engaging a catch on the trigger body with a catch surface on the trigger. 
     In another embodiment, the method also includes providing a wedge member capable of insertion between the trigger and the housing and securing the wedge member to the trigger. The wedge member prevents the trigger from returning fully to the zero position. The wedge member may be part of the trigger attachment or a component separate from the trigger attachment body. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a side view of a controller of the prior art showing the trigger in the zero position. 
         FIG. 1B  is a side view of the controller of  FIG. 1A  showing the trigger in the end position. 
         FIG. 2A  is a side view of another embodiment of a controller of the prior art showing the trigger in the zero position. 
         FIG. 2B  is a side view of the controller of  FIG. 2A  showing the trigger in the end position. 
         FIG. 3  is a front and side perspective view of an embodiment of a trigger attachment of the present invention. 
         FIG. 4  is a side elevational view of the trigger attachment of  FIG. 3 . 
         FIG. 5  is a side and rear perspective view of the trigger attachment of  FIG. 3  showing the recess. 
         FIG. 6  is a front and side perspective view of another embodiment of a trigger attachment of the present invention. 
         FIG. 7  is a side elevational view of the trigger attachment of  FIG. 6 . 
         FIG. 8  is a side and rear perspective view of the trigger attachment of  FIG. 6  showing the recess. 
         FIG. 9  is a front and side perspective view of part of a controller and one embodiment of a trigger attachment positioned for installation using an attachment bracket on the trigger. 
         FIG. 10  is a front and side perspective view of another embodiment of a trigger attachment referred to as a trigger cover. 
         FIGS. 11A-11E  are side elevational views of a trigger and section of a controller housing showing the various ranges of motions of the trigger with and without a trigger attachment. 
         FIG. 12  is a front and side perspective view of one embodiment of a trigger attachment shown installed on a trigger. 
         FIG. 13  is a front and side perspective view of another embodiment of a trigger attachment shown installed on a trigger. 
         FIG. 14  is a side perspective view of the trigger attachment and controller of  FIG. 14  showing a void in the side of the trigger that is engaged by the trigger attachment. 
         FIG. 15  is a top plan view of another embodiment of a trigger attachment shown installed on a trigger of a controller and a user&#39;s finger on the sloped outer front surface. 
         FIG. 16  is a bottom and side perspective view of the trigger attachment of  FIG. 14  showing the user&#39;s finger hugged by the curvature of the sloped outer front surface of the trigger attachment. 
         FIG. 17  is a bottom plan view of the trigger attachment of  FIG. 14  showing the lower housing contact surface of the trigger attachment. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present invention are illustrated in  FIGS. 3-17 . Referring to  FIGS. 3-5 , a left and front perspective view, a side view, and a right and rear perspective view, respectively, illustrate one embodiment of a trigger attachment  100 . Trigger attachment  100  has an attachment body  110  sized and shaped to be mounted on a trigger  15 . Attachment body  110  has an upper limb  104  and a lower limb  106  that each extend from an attachment tip  116 . In doing so, attachment body  110  defines a rear-facing (i.e., away from tip  116 ) recess  112  sized and shaped to mate with trigger  15  of a controller  10 . Upper limb  104  and lower limb  106  define recess  112  with an acute angle  108  to receive trigger tip  27  therein with an inside surface or receiving face  114  of recess  112  abutting finger contact surface  25  of trigger  15 . In some embodiments, attachment body  110  is retained on trigger  15  by frictional engagement or interference fit with trigger  15 . To facilitate the frictional engagement, some embodiments of trigger attachment  100  are made of resilient materials, such as silicone rubber, foam, or the like. Attachment body also defines an outside surface  115  that extends along a sloped outer front surface  118 , around attachment tip  116 , and along a bottom surface  120 . 
     In some embodiments as shown in  FIG. 4 , a thickness T of attachment body  110  from receiving face  114  to outside surface  115  is non-uniform. For example, thickness T is greater towards attachment tip  116 . Optionally, sloped outer front surface  118  forms a concave slope as it extends towards attachment tip  116  and has a convex cross section as it extends laterally from edge to edge. These features result in a contoured trigger attachment  100  that provides increased trigger surface area. One benefit of such a contour is that the resting position of a finger on the sloped outer front surface  118  is ergonomic and comfortable. Additionally, the user&#39;s finger is held in place on sloped outer front surface  118  with little effort. Such a contour also provides a greater surface area and therefore an increased directional range of finger movement that provides quicker activation of trigger  15 . Pressure from the user&#39;s finger in a direction generally perpendicular to any one of various locations on sloped outer front surface  118  results in movement of the trigger  15  through the take-up  23  and towards the active zone  21 . Additionally, the curved contour of trigger attachment  100  is aesthetically pleasing. 
     Lower limb  106  extends to terminate at a lower housing contact surface  122  generally facing in a rearward direction or away from attachment tip  116 . When trigger tip  27  is received in recess  112 , lower housing contact surface  120  is positioned to abut controller housing  13  to restrict trigger movement when the trigger is activated. As such, lower housing contact surface  120  reduces the trigger range of motion  20 . More particularly, lower housing contact surface  120  is positioned to reduce over travel  24  of trigger  15  beyond the active zone  21  by stopping trigger  15  prior to reaching end position  19 . 
     Optionally, upper limb  104  extends to define an upper housing contact surface  126  that is positioned to contact controller housing  113  when trigger  15  returns towards the zero position  18 . By restricting movement of trigger  15  as it pivots towards zero position  18 , upper housing contact surface  126  reduces take-up  23  or “dead zone” at the beginning of a trigger pull. As a result, the take-up  23  of trigger  15  is reduced. In one embodiment, upper limb  104  wedges between trigger  15  and housing  13  when trigger  15  returns towards zero position  18 , where upper housing contact surface  126  is a top surface that contacts housing  13 . Thus, upper limb  104  acts as a wedge  129  to prevent trigger  15  from returning fully to the zero position  18 . Other embodiments of wedge member  129  are discussed below with reference to  FIG. 11 . 
     In other embodiments, upper housing contact surface  126  is a rear-facing surface (i.e., facing away from attachment tip  116  and towards controller  10 ). Similar to lower housing contact surface  122 , rear-facing upper housing contact surface  126  is positioned to abut controller housing  13  to reduce the trigger range of motion  20 . For example, upper housing contact surface  126  abuts housing  13  as trigger returns towards the zero position, thereby restricting trigger movement and reducing the trigger range of motion  20 . 
     In some embodiments, upper limb  104  defines an upper catch  128  with an upper catch surface  128   a  facing generally towards lower limb  106 . Upper catch  128  is useful to engage an edge or recess along top  15   a  of trigger  15 . When upper limb  104  extends to act as a wedge  129 , upper catch  128  may engage a groove in trigger  15  to help maintain the position of wedge  129  as trigger  15  pivots. 
     In some embodiments, lower limb  106  additionally defines a lower catch  124  to engage a rear edge  15   b  (shown in  FIG. 1B ), catch surface, or other feature defined on some embodiments of trigger  15 . Lower catch  124  has a lower catch surface  124   a  that faces generally towards upper limb  104 . Lower catch  124  extends fully or partially across the width W of trigger attachment  100 . In some embodiments, lower catch  124  is a narrow tab or extension from lower limb  106  that is sized to engage the edge or catch surface on trigger  15 . For example, lower catch  124  is a relatively narrow strip of material with lower catch surface  124   a  that extends into housing  13  to hook a rear edge of trigger  15 , where lower catch  124  does not interfere with actuation of trigger  15 . By extending along the bottom surface of trigger  15 , lower catch  124  in some embodiments helps align trigger attachment  100  on trigger  15 . 
     Trigger attachment  100  prevents movement of trigger  15  through the full trigger range of motion  20  by contacting housing  13  of controller  10  to reduce take-up  23  and/or over travel  24 . Trigger attachment  100  is dimensioned to reduce the range of trigger travel  20  while permitting the user to execute the intended function of the trigger  15  without excessive movement outside of the active zone  21 . Embodiments of trigger attachment  100  are dimensioned to define various corresponding trigger ranges of motion  20  that accommodate a wide variety of videogame controllers  10  and active zones  21  of different sizes. For example, lower limb  106  in some embodiments of trigger attachment  100  extends rearwardly in different amounts. The length of lower limb  106  from inside surface  116   a  of attachment tip  116  defines the point within trigger range of motion  20  where lower housing contact surface  122  makes contact with housing  13 . Thus, for example, the user may own several sets of trigger attachments  100  where each set is sized for short, medium, or long trigger range of motion  20 . When switching between games that require different trigger ranges of motion  20 , the user then may switch trigger attachments  100  as needed to provide the appropriate range of motion  20 . 
     In some embodiments, upper limb  104  is configured to include a wedge  129  that fits between housing  13  and trigger  15 . Wedge  129  may be part of upper limb  104  that defines upper housing contact surface  126 . Alternately, wedge  129  is distinct and separate from attachment body  110 . In such an embodiment, wedge  129  may be secured permanently or temporarily to trigger top  15   a  with adhesives, mechanical fasteners, snap-lock features, or the like. Wedge  129  reduces take-up  23  without diminishing the ability of trigger  15  to initiate and carry out commands. As with lower housing contact surface  122 , wedge  129  or upper housing contact surface  126  may be dimensioned to reduce take-up  23  in various amounts to accommodate different trigger designs of different controllers  10 . In some embodiments, wedge  129  is part of upper limb  104  and includes upper catch  128  and upper housing contact surface  126  as different faces of wedge  129 . 
     Referring to  FIG. 5 , some embodiments of trigger attachment  100  include optional adhesive  134  disposed on all or part of receiving face  114  for the purpose of fixing trigger attachment  100  to trigger  15 . Adhesive  134  binds trigger attachment  100  to trigger  15  with sufficient strength to endure many repeated cycles of user manipulation. In some embodiments, the user applies adhesive  134  to trigger attachment  100  just prior to installation on trigger  15 . In other embodiments, trigger attachment  100  includes adhesive  134  already disposed and including a lift-off backing (not shown) that the user removes just prior to installing trigger attachment  100  on trigger  15 . In some embodiments, adhesive  134  is a pressure-sensitive adhesive that is activated when the user applies sufficient pressure. Other variations on adhesive  134  known in the art are also acceptable. 
     Referring now to  FIGS. 6-8 , a right and front perspective view, a right-side view, and a left and rear perspective view, respectively, illustrate another embodiment of trigger attachment  100  shaped for a different embodiment of trigger  15 . As with the embodiment of trigger attachment  100  shown in  FIGS. 3-5 , the embodiment shown in  FIGS. 6-8  has trigger body  110  with an upper limb  104  and lower limb  106  each extending away from attachment tip  116 . Trigger attachment  100  defines recess  112  shaped to receive and mate with trigger  15 . As shown in  FIGS. 6-8 , lower housing contact surface  122  faces rearwardly away from attachment tip  116  and is positioned to contact housing  13  when trigger  15  is pressed by the user. Sloped outer front surface  118  forms a concave slope as it extends towards attachment tip  116  and has a domed or convex cross section across the width W of trigger attachment  100 . Bottom surface  120  is concave to prevent interference with the user&#39;s other fingers when pressing trigger  15 . 
     Referring now to  FIG. 9 , some embodiments of trigger attachment  100  include a mounting bracket  150 . Mounting bracket  150  is used to attach trigger attachment  100  to trigger  15 . In one embodiment, mounting bracket  150  is secured to finger contact surface  25  of trigger  15  by adhesive. In one embodiment, mounting bracket  150  is shaped with overhanging or rounded outer bracket edges  152   a ,  152   b . Receiving face  114  of attachment body  110  has corresponding mating features that mate with and engage outer bracket edges  152   a ,  152   b  in sliding engagement, snap fit, or other engagement to hold attachment body  110  to mounting bracket  150 , and therefore to trigger  15 . Mating bracket  150  facilitates attachment body  110  being releasably attached to trigger  15  and use of interchangeable trigger attachments  100 . In some embodiments, upper catch  128  engages upper bracket edge  152   c . Since trigger tip  27  is received in recess  112 , attachment body  110  may be stretched or deformed slightly during installation so that upper catch  128  will reach to upper bracket edge  152   c . Thus, when attachment body  110  attempts to resume a relaxed state, upper catch  128  may be at tension while gripping upper bracket edge  152   c  and therefore releasably lock attachment body  110  to trigger  15 . 
     In some embodiments, one or more locking tab is formed on the either the trigger body  110  or mounting bracket  150  to engage the other component so as to releasably lock the two components together. For example, tabs with a catch surface similar to upper catch  128  as shown in  FIG. 9  are disposed along attachment body  110  to engage outer bracket edges  152   a ,  152   b . The snap-fit between trigger body  110  and mounting bracket  150  provide one method to secure trigger attachment  110  to trigger  15 . Mounting bracket  150  may alternately be installed on other faces of trigger  15 , such as a bottom face  26 , where lower catch  124  (shown in  FIG. 5 ) engages mounting bracket  150 . 
     In some embodiments, mounting bracket  150  is ferromagnetic or includes a bracket ferromagnetic member  154 . In such embodiments, attachment body  110  also includes a body ferromagnetic member  156 , such as a magnet, positioned to mate with bracket ferromagnetic member  154 . For example, mounting bracket  150  with bracket ferromagnetic member  154  is affixed to trigger  15 . Attachment body  110  is then mounted to mounting bracket  150 , which includes body ferromagnetic member  156 , such as steel. Attachment body  110  is therefore retained on trigger  15  using magnetic attraction between the ferromagnetic members  154 ,  156 , but may be removed by the user as desired. The magnetic force generated by the ferromagnetic members  154 ,  156  is sufficient to permit use of the trigger attachment  100  without the decoupling from trigger  15  during normal operation and including contact between trigger attachment  110  and housing  13 . 
     Referring now to  FIG. 10 , a front perspective view illustrates an embodiment of a trigger cover  200 . Trigger cover  200  attaches to mounting bracket  150  (shown in  FIG. 9 ) with a sliding motion in which corresponding features (e.g., mating rails) on the two elements create a releasable, but secure connection. In one embodiment, for example, trigger cover includes one or more catches  130  along its edges or disposed on receiving face  114  to engage mounting bracket  150 . Trigger cover lacks lower housing contact surface  122  and upper housing contact surface  126  (shown in  FIG. 5 ). Accordingly, trigger cover  200  may be interchanged with trigger attachment  100  to allow full trigger range of motion  20 . Thus, when used with mounting bracket  150 , trigger cover  200  provides an option to achieve full trigger range of motion  20  without removing mounting bracket  150  from trigger  15 . Being interchangeable with trigger attachment  100 , trigger cover  200  is desirable when playing videogames that do not benefit from, or are inhibited by, reduced trigger range of motion  20 . In some videogames, only the left or right trigger may benefit from reduced trigger range of motion. In this scenario the trigger cover  200  may be used on just the left or right trigger  15  to create a matching aesthetic and reach while only limiting the movement of either the right or left controller trigger  15 . Additionally, the trigger cover  200  may provide added surface area for resting as well as additional directions in which to exert force on trigger  15  to cause trigger  15  to initiate a signal. 
     Optionally, trigger cover  200  or trigger attachment  100  includes an alignment/locking tab  210 . In combination with upper catch  128  on trigger attachment  100  or with catches  130  on trigger cover  200 , alignment/locking tab mechanically, but releasably locks trigger cover  200 /trigger attachment  100  to trigger  15  to ensure successful depression and return of trigger  15  towards zero position  18 . Alignment/locking tab  210  extends rearwardly from lower limb  106  of trigger attachment  100  or from lower end  202  of trigger cover  200 . Alignment/locking tab  210  enters housing  13  to align and stabilize trigger attachment  100 /cover  200 . When the trigger  15  is pressed by the user, trigger attachment  100 /cover  200  is under the most stress and most subject to release from trigger  15 . Alignment/locking tab  210  stabilizes trigger attachment  100 /cover  200  and prevents its removal from trigger  15  during game play. In general, alignment/locking tab  210  is made of a strip of material sufficiently thin to pass between trigger  15  and housing  13  without interfering with the trigger movement. In some embodiments, alignment/locking tab  210  is made of a resilient material that can be stretched to engage rear edge  15   a  of trigger  15  and pull trigger attachment  100  towards trigger tip  27 . 
     The trigger limiter embodiments disclosed herein may be formed from a wide variety of materials including plastics, metals, and metal alloys. 
     Referring now to  FIGS. 11A-11E , and with continued reference to  FIGS. 1-2 , an embodiment of trigger  15  is shown in various positions with and without trigger attachment  100 . The position of rear edge  15   b  in each figure can be used to identify the difference in the position of trigger  15  between zero position  18  and end position  19 .  FIGS. 11A and 11B  illustrate side views of trigger  15  with a section of housing  13  and without trigger attachment  100 .  FIG. 11A  illustrates trigger  15  in its normal resting state biased to the zero position  18 . Contact surface  25  has a trigger radius of curvature  15   c  and a contact surface length  25   a  from trigger top  15   a  to trigger tip  27 .  FIG. 11B  illustrates trigger  15  in its fully depressed state or end position  19 . 
       FIGS. 11C and 11D  show trigger  15  with trigger attachment  100  installed on trigger  15 . As shown in  FIG. 11C , upper limb  104  extends along finger contact surface  25  and extending to occupy the space between top  15   a  of trigger  15  and housing  13 . Upper housing contact surface  126  engages housing  13  to restrict trigger  15  from returning fully to the zero position  18  shown in  FIG. 11A , thereby reducing take-up  23  (shown in  FIG. 1B .)  FIG. 11D  illustrates trigger  15  pivoted towards end point  19 , but is prevented from fully reaching that position due to lower housing contact surface  122  contacting housing  13 .  FIG. 11D  illustrates how trigger attachment  100  reduces the over travel  24  (shown in  FIG. 1B ) of trigger  15 . Also shown in both of FIGS.  11 C and  11 D, trigger attachment  100  includes alignment/locking tab  210 , which extends from lower limb  106  into housing  13  to engage rear edge  15   b  of trigger  15 . Alignment/locking tab  210  helps retain trigger attachment  100  on trigger  15 . 
       FIG. 11D  also illustrates user contact surface length  118   a  between upper surface  105  and attachment tip  116 . User contact surface  118  also defines an attachment radius of curvature  111 . Table 1 below shows length corresponding to contact surface length  25   a  of triggers  15  and user contact surface length  118   a  for trigger attachment  100 . Table 1 also shows the length and radius corresponding to the trigger radius of curvature  15   c  or attachment radius of curvature  111 . 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Properties of Trigger Attachment and Triggers 
               
            
           
           
               
               
               
               
            
               
                   
                 Trigger 15 for 
                 Trigger 15 for 
                 Trigger 
               
               
                   
                 Playstation 
                 XBox 
                 attachment 100 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Length 
                 0.70″ 
                 0.87″ 
                 0.94″ 
               
               
                   
                 Radius 
                 1.4″ 
                 2.25″ 
                 0.75″ 
               
               
                   
                   
               
            
           
         
       
     
     In some embodiments, trigger attachment  100  has a user contact surface length  118   a  that is greater than contact surface length  25   a  of a provided trigger  15 . That is, trigger attachment  100  increases the contact surface length  25   a . Trigger attachment  100  in some embodiments also has attachment radius of curvature  111  that is less than trigger radius of curvature  15   c . In some embodiments, attachment radius of curvature  111  changes along user contact surface length  118   a , where attachment radius of curvature  111  is smaller towards attachment tip  116  These features allow trigger attachment to be more comfortable for the user by more closely following the curvature around one&#39;s finger, which typically has a radius of about 0.25″. Thus, the user can better “hook” trigger attachment  100  with the finger. An increased user contact surface length  118   a  allows enough space for trigger attachment to attain the reduced attachment radius of curvature  111 . A trigger may only contact about 15% of the circumferential finger surface. In comparison, trigger attachment  100  contacts approximately 30-40% of the circumferential finger surface. 
       FIG. 11E  illustrates trigger  15  with another embodiment of trigger attachment  100  and separate wedge  129  adhered to trigger  15 . Wedge  129  fits between top  15   a  of trigger  15  and housing  13  to prevent trigger  15  from returning fully to the zero position  18 . Thus, trigger  15  in  FIG. 11E  is “primed” with a reduced take-up  23  compared to trigger  15  in  FIG. 11A , which lacks wedge  129 . 
     Referring now to  FIG. 12 , a perspective view illustrates one embodiment of trigger attachment  100  installed on trigger  15  of a controller  10  such as a controller  10  sold under the trademark PlayStation®. Lower housing contact surface  122  is positioned to abut housing  13  when trigger  15  is pressed by the user to reduce over travel  24  (shown in  FIG. 1B ) of trigger  15 . Upper catch  128  engages top  15   a  of trigger  15  to help retain trigger attachment  100  on trigger  15 . Upper housing contact surface  126  races rearwardly and abuts housing  13  to reduce the take-up  23  (shown in  FIG. 1B ) of trigger  15 . Sloped outer front surface  118  provides a comfortable grip to the user with a modified surface position compared to finger contact surface  25  of trigger  15 . 
     Referring now to  FIG. 13 , a perspective view illustrates one embodiment of trigger attachment  100  installed on trigger  15  controller  10  such as a controller  10  sold under the trademark Xbox®. Lower housing contact surface  122  is positioned to abut housing  13  when trigger  15  is pressed by the user, thereby reducing the over travel  24  (shown in  FIG. 1B ) of trigger  15 . Here, trigger attachment  100  does not affect the take-up  23  of trigger  15  and instead only affects over travel  24 . Sloped outer front surface  118  provides a comfortable grip to the user with a modified surface position compared to finger contact surface  25  of trigger  15 . 
     Referring now to  FIG. 14 , a portion of controller  10  is illustrated from a side perspective view with trigger attachment  100  installed on trigger  15 . Additional button  16  is positioned above trigger  15 . Trigger attachment  100  remains engaged with trigger  15  due to a snap fit with voids or recesses (not shown) in trigger  15 . Sloped outer front surface  118  provides various directions of engagement indicated by arrows  119   a ,  119   b , respectively, along which the user may apply force to trigger  15  via trigger attachment  100 . For example, by positioning the user&#39;s finger  300  (shown in  FIG. 15 ) closer to upper housing contact surface  126  (or similar position), the user may pull rearwardly to activate trigger function. In contrast, by positioning the user&#39;s finger  300  closer to attachment tip  116 , the user may pull down and rearwardly to activate trigger  15 . Thus, the user may find a direction of engagement  119  that best suits the user&#39;s hand size and hand placement on controller  10 . When the point of contact between finger  300  and trigger  15  changes during a trigger pull, such as when the user rolls the finger  300  along trigger  15 , the increased change in direction of engagement  119  on sloped outer front surface  118  compared to user contact surface  25  results in improved trigger responsiveness for the user. 
     Referring now to  FIG. 15 , a top view shows a portion of controller  10  of  FIG. 14 , where trigger attachment  100  is installed on trigger  15 . An additional button  16  (shown in  FIG. 14 ) is omitted to more clearly see trigger attachment  100  and trigger  15 . Part of trigger  15  extending into trigger attachment  100  is shown in broken lines. Trigger attachment  100  abuts contact surface  15  and wraps around trigger sides  15   c ,  15   d . In cases where trigger  15  defines a void  14 , trigger attachment  100  preferably occupies void  14  to further secure trigger attachment  100  on trigger  15 . A user&#39;s finger  300  is positioned on sloped outer front surface  118  of trigger attachment  100  to actuate the trigger function. 
     Referring now to  FIG. 16 , controller  10  of  FIG. 14  is shown in a bottom and side perspective view. Trigger  15  is visible behind trigger attachment  100  and below additional button  16 . Due to the curvature of sloped outer front surface  118 , user&#39;s finger  300  is at rest against sloped outer front surface  118  in a more ergonomic position. This ergonomic position allows for a more relaxed finger position on trigger  15 . 
     Referring now to  FIG. 17 , a bottom view of controller  10  of  FIG. 14  shows trigger attachment  100  installed on trigger  15 . Lower housing contact surface  122  extends rearwardly from lower limb  106  towards housing  13  to reduce over travel  24  of trigger  15 . 
     Users of trigger attachment  100  benefit by reducing unwanted motion in the trigger range of motion  20 . Other benefits of embodiments of trigger attachment  100  include improved comfort and ergonomics for actuating trigger  15 . Depending on the embodiment, trigger attachment  100  may reduce the over travel  24 , take-up  23 , or both. For games where only one trigger  15  benefits from reduced trigger range of motion  20 , trigger cover  200  may be used to provide the same reach and feel for right and left triggers  15 . Alternately, trigger cover  200  may be used interchangeably with trigger attachment  100  when no reduction in trigger range of motion  20  is desired or necessary. 
     Although exemplary embodiments of the present invention have been described herein, the above description is merely illustrative. Further modification of the invention herein disclosed will occur to those skilled in the respective arts and all such modifications are deemed to be within the scope of the invention as defined by the appended claims.