Patent Publication Number: US-11391530-B2

Title: Non-contact electro-magnetic actuator and method

Description:
PRIORITY CLAIM AND CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of and claims priority to U.S. provisional patent application no. 62/837,247, entitled “Non-Contact Electro-Magnetic Actuator and Method” which was filed on Apr. 23, 2019, the entire disclosure of which is incorporated herein by reference. The present application is also related to commonly owned application Ser. No. 14/462,348, filed Aug. 14, 2014, now U.S. Pat. No. 9,267,750, the entire disclosure of which is also incorporated herein by reference. 
    
    
     BACKGROUND 
     Field of the Invention 
     The present invention relates to firearms and more particularly to trigger mechanisms for use in rifles and other manually actuable instruments which carry or are configured with electro-optic sensors, target designators or other electronic accessories when in use by a shooter. 
     Discussion of the Prior Art 
     Rifle marksmanship has been continuously developing over the last few hundred years, and now refinements materials, manufacturing processes and portable sensors have made increasingly accurate aimed fire possible. These refinements have made previously ignored ergonomic or human factors more significant as sources of error. 
     The term “rifle” as used here, means a projectile controlling instrument or weapon (e.g., configured to aim and propel or shoot a projectile, and triggers or firearm actuator systems are discussed principally with reference to their use on rifles and embodied in mechanisms commonly known as trigger assemblies. Referring to  FIGS. 1A-1C , a standard M40 rifle  10  (e.g., as further illustrated and described in USMC TM 05539-IN) has receiver assembly  12  with trigger assembly  20  carried within rifle stock  16  with trigger shoe  20 S projecting downwardly through stock opening  22  as defined in stock channel  24  when receiver assembly  12  is installed in stock  16  and aligned therein so that barrel  14  is supported with the receiver&#39;s lug held in the stock&#39;s lug receiving recess  28 . When assembled, rifle  10  provides easy access for the shooter or user to reach and manipulate trigger shoe  20 S and the trigger assembly&#39;s safety lever  18 . 
     It will become apparent, however, that trigger mechanisms for manually actuable instruments may include devices other than rifles, and may be used on instruments or weapons other than rifles which are capable of controlling and propelling projectiles (e.g., rail guns or cannon). The prior art provides a richly detailed library documenting the process of improving the ergonomics of actuating rifles and other firearms (e.g., as shown in  FIGS. 1A-1E ) and other manually actuable instruments. 
     Modern firearms such as rifles (e.g.,  10 ,  40 A or  40 B) make use of optical and electro-optical accessories such as rifle scopes (e.g., S 1  or S 2 , with electro-optic illuminated reticles (not shown)), coaxially aligned red-dot sights (e.g., S 3 ) night vision sights (e.g., S 4 ) or thermal sights (e.g., S 4 ), and these typically each include controls (e.g., “off-on”) to actuate control or power supply circuitry (not shown). When used in the field, these auxiliary or accessory systems (e.g., S 1 -S 5 ) require the user or shooter to examine and manipulate the control buttons or switches of each device separately, sometimes in the dark. 
     Some creators of entirely new rifle systems have attempted to make the systems more user friendly and faster by incorporating electronic control circuits and sensors directly into a trigger assembly, which necessarily means that the user&#39;s and their armorers must now cope with a new, untested “hybrid” electromechanical trigger assembly which may, if the new electronics fail, render the firearm unusable in the field (or irreparable at the field level). For example, the system illustrated and described in TrackingPoint&#39;s U.S. Pat. No. 10,001,335 shows a trigger assembly which differs entirely from the tried-and true trigger assembly  20  used in standard M40 or M24 rifles, and these new hybrid trigger assemblies have been found wanting and rejected due to their unwelcome combination of fragility and strangeness (as viewed by the training and maintenance cadre). 
     Returning to  FIGS. 1A-1E , the rifles (e.g.,  10 ,  40 A or  40 B) are configured to fire ammunition cartridges that include a projectile seated in a casing. The casing has an internal cavity defined therein that contains a charge of rapidly combusting powder. A primer is seated in a recess formed in a rear portion of the casing. A hole in the primer casing places the primer in communication with the internal cavity containing the power. A projectile is seated in the front portion of the casing such that the powder is more or less sealingly contained in the casing between the primer and the projectile. 
     An action, such as a bolt action (e.g., as seen in  FIGS. 1A and 1B ), is used to fire the cartridge. For example, the action can include a striker that carriers a firing pin. The striker can be coupled to a biasing member, such as a spring. The spring provides a motive force for the striking to cause the firing pin to impact the primer. More specifically, the spring can be compressed, or cocked, by drawing the striker rearwardly. Engagement between a sear and the striker can maintain the striker in a cocked position. 
     The action can then be used to advance the cartridge into a firing chamber ahead of firing. While in the firing chamber, a trigger mechanism can be used to release the sear to cause the firing pin to strike the primer, causing the primer to ignite. The ignition is directed to the powder, which burns within the casing. The powder burns within the casing to generate a rapidly expanding gas, which propels the projectile out of the casing and through the barrel. 
     Safety mechanisms are often used in the trigger mechanism to selectively control whether the trigger mechanism may release the sear. However, safety mechanisms may interfere with trigger feel, trigger pull or other factors which directly and adversely affect the shooter&#39;s ability to precisely control trigger actuation. 
     When firing a shot, a trained shooter will carefully control breathing motions, check sight alignment as part of the continuous aiming process, and then carefully apply an initial pressure to the trigger, gradually increasing force to squeeze the trigger and “break” the shot at a moment which is chosen by the shooter to maximize the likelihood of a “hit” on the target. The shooter&#39;s ability to repeatably and precisely execute this planned sequence of steps is determined in part by the trigger assembly&#39;s ergonomics and consistent, repeatable operation. Bad triggers exhibit uneven response to trigger finger pressure (or “creep”) and do not actuate or “break” cleanly and consistently. Often, a marksman or precision shooter will struggle to adjust the performance on a trigger to maximize that specific shooter&#39;s ability to precisely control trigger actuation or “break”. 
     Traditional rifle triggers have been categorized as single stage triggers or two stage triggers (e.g.,  20 ). Two-stage triggers are often used on military weapons. As the name implies, the trigger take-up is in two stages. The first stage is usually about ¼″ of lighter “slack”, before the second stage trigger pull begins, which ends with the trigger break. There is a difference in the weight of the trigger pull between the two stages which can be easily felt, where the first stage travel is light and the second stage requires notably greater force. A single-stage trigger does not typically have nearly as much travel as a two-stage trigger, so the shooter simply applies trigger pressure or force until the trigger breaks. Single stage triggers are more often used on sporting rifles. 
     Product liability lawsuits have exacerbated the shooter&#39;s ergonomics problems by forcing most manufacturers to design trigger assemblies which are nearly impossible for the shooter or user to tune or adjust. Some shooters will replace the entire trigger assembly in a rifle having a “lawyer&#39;s trigger” in the hopes of improving trigger adjustability. Shooters and those configuring Precision rifles (e.g.,  10 ) with adjustable triggers often also want to be able to use sighting and other accessories in a manner which does not create new problems with reliability of the overall rifle system. 
     There is a need, therefore, for a rifle system having a robust and reliable trigger assembly which can be used to enhance the ergonomics of trigger actuation and allow the shooter or user to tune or customize the trigger for his or her needs while also aiding in the use of electro-optical and other accessories which may be mounted on or configured with the rifle system. 
     The subject matter claimed herein is not limited to embodiments that solve any of the cited disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one exemplary technology area where some examples described herein may be practiced. 
     SUMMARY OF THE INVENTION 
     Briefly, and in accordance with preferred embodiments, the present invention incorporates a rifle system having a robust and reliable trigger assembly which can be used to enhance the ergonomics of trigger actuation and allow the shooter or user to tune or customize the trigger for his or her needs while also aiding in the use of electro-optical and other accessories which may be mounted on or configured with the rifle system. 
     The rifle system of the present invention has a trigger motion sensor which is proximate a trigger assembly when the receiver assembly is installed in the stock (or chassis). The trigger motion sensor is configured to sense, from a selected standoff distance, without contacting or interfering the trigger assembly in any way, at least one of (a) said first stage movement or (b) actuation of said safety lever, and generate a “trigger motion sensed” signal in response thereto. 
     The rifle system of the present invention preferably includes a drop-in adjustable trigger assembly comprising a housing having a first side plate and a second side plate which carry a pivoting bolt sear which is connected to a sear safety linkage. The housing has a sear safety linkage slot defined therein which guides the pivoting sear safety linkage in response to actuation of an upwardly projecting thumb safety lever&#39;s actuation. A trigger bracket preferably carries a removable trigger shoe and is configured to pivot within the housing about a pivot point positioned within the housing&#39;s lower portion. This trigger bracket carries an adjustable rocker having (preferably) a first stage movement adjustment and a second stage length adjustment. The pivoting safety mechanism&#39;s safety linkage pivots rearwardly to push upon or cam a bolt sear upwardly, thus disengaging the bolt sear from the trigger sear. 
     The drop-in trigger assembly of the present invention is compact and robust, due in part to the configuration of the housing&#39;s parallel, planar left or first side plate and the second or right side plate which carry, orient and support the fixed and moving components of the assembly, including the pivoting safety lever which is rotatable about a transverse pin&#39;s axis from a forward “safety off” position to a rearward “safety on” position. The pivoting trigger bracket carries the adjustable transverse rocker member, which has an internal threaded bore that engages a rocker set screw to raise or lower the rocker, and the lower the rocker is positioned, the smaller the trigger&#39;s 1st stage take-up, because of an angled forward face on the pivoting trigger sear. As the transverse rocker moves down, the mechanical advantage is decreased, thus increasing the 2 nd  stage weight of pull. The housing also carries a transverse trigger sear pin which defines the pivot axis for the trigger sear. The trigger sear has a forward face on the forward side of the pivot and has its trigger sear engagement surface on the rearward side of the pivot. The trigger assembly&#39;s sideplates preferably define unobstructed openings or non-ferrous segments proximate the trigger bracket, the sear&#39;s engagement face, the trigger shoe and the safety lever. 
     The rifle or portable firearm assembly of the present invention is configured to work with user-actuable sensors and systems and includes a removable receiver assembly including a receiver coaxially aligned with and attached to a barrel, where the receiver is attached to and responsive to the trigger assembly. The rifle system of the present invention has a stock or chassis having a middle section adapted to removably receive the receiver assembly its trigger assembly, and the stock or chassis middle section defines a lumen or cavity having a trigger motion sensing sidewall segment which is configured proximate the trigger assembly when the receiver is installed in the stock or chassis; where the stock or chassis is configured to receive and support the user-actuable sensors and systems (e.g., any of S 1 -S 4 ). The trigger motion sensing sidewall segment includes a trigger motion sensor which does not physically contact or attach to the trigger assembly and is instead spaced from every component of the trigger assembly by a selected “clearance” distance (e.g., at least 0.5 mm) when the receiver is installed in said stock or chassis. 
     In the rifle system of the present invention, the trigger assembly comprises a housing incorporating first and second spaced wall plates, a trigger bracket pivotally mounted between the wall plates which is configured to pivot within the housing about a pivot point positioned within the housing and a trigger shoe carried by said trigger bracket which is configured to disengage a firing mechanism in response to a force applied by the shooter or user. The trigger assembly also includes a safety mechanism actuable by a safety lever mounted on the housing where the trigger assembly is configured to provide a first stage movement in response to a first force applied by a user and, if the user applies a second force greater than said first force, a second stage movement. 
     Since the trigger assembly sideplates define openings or non-ferrous segments proximate at least one of the trigger bracket, trigger shoe and safety lever, those trigger assembly sideplate openings or non-ferrous segments are aligned with at least one of the trigger bracket, said trigger shoe and said safety lever to define a transverse trigger motion sensing axis. The transverse trigger motion sensing axis is aligned to intersect the stock middle section&#39;s trigger motion sensor which is proximate said trigger assembly when said receiver is installed in said stock or chassis. The trigger motion sensor is configured to sense, from a selected standoff distance, without contacting or interfering the trigger assembly in any way, at least one of (a) first stage movement or (b) actuation of the safety lever, and generate a “trigger motion sensed” signal in response thereto for transmission to auxiliary accessories (e.g., such as one or more of scopes or sights S 1 -S 4 ). 
     In an exemplary embodiment, the trigger bracket, trigger shoe and safety lever are all made from steel or another magnetic flux focusing material, and the transverse trigger motion sensing axis substantially intersects a Hall effect trigger motion sensor which does not physically contact or attach to the trigger assembly and is instead spaced from every component of said trigger assembly by a selected “clearance” distance (e.g., at least 0.5 mm) when the receiver is assembled or installed in the stock or chassis. 
     Alternatively, the rifle or portable firearm assembly can include a trigger bracket, trigger shoe and said safety lever which are made from steel or another substantially opaque material, and the transverse trigger motion sensing axis substantially intersects an optical sensor which does not physically contact or attach to the trigger assembly and is instead spaced from every component of the trigger assembly by a selected distance (e.g., at least 0.5 mm) when the receiver is installed in the stock or chassis. 
     The rifle or portable firearm assembly may be a standard (e.g., Remington 700 style, M40 or M24) receiver, attached to and responsive to the trigger assembly of the present invention where the trigger motion sensor is configured to sense at least one of (a) first stage movement, (b) second stage movement or (c) actuation of the safety lever and generate a trigger motion sensed signal for the user-actuable sensors and systems (e.g., S 1 -S 4 ) in response. The rifle or portable firearm assembly of the present invention preferably has a stock or chassis with a bore axis extending along a longitudinal axis comprising a forward section adapted to receive a portion of the barrel where the middle section is aligned with the forward section and adapted to receive the receiver carrying the trigger assembly, where the stock or chassis middle section cavity trigger motion sensing sidewall segment is configured beside and proximate the trigger assembly when the receiver is installed in the stock or chassis. In the exemplary embodiment, the stock or chassis is configured with power and communication connections to provide power and communication between the trigger motion sensing sidewall segment and the user-actuable sensors and systems (e.g., S 1 -S 4 ). 
     The above and still further features and advantages of the present invention will become apparent upon consideration of the following detailed description of a specific embodiment thereof, particularly when taken in conjunction with the accompanying drawings, wherein like reference numerals in the various figures are utilized to designate like components. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A, 1B and 1C  illustrate a prior art firearm of the type (e.g., a USMC M40) which incorporates a standardized trigger assembly well understood by shooters and armorers. 
         FIGS. 1D and 1E  illustrate another prior art firearm of the type (e.g., a US M110 SASS) which incorporates another form of standard trigger assembly well understood by shooters and armorers. 
         FIGS. 2-5  illustrate exemplary embodiments of the rifle or portable firearm system trigger assembly configured to work with user-actuation detection sensors and systems in accordance with the method of the present invention. 
         FIG. 6  illustrates an exemplary embodiment of the rifle or portable firearm system configured to provide with a user-actuable trigger motion sensor system in accordance with the present invention. 
         FIG. 7  illustrates an exemplary embodiment of the rifle or portable firearm system configured to work with user-actuable sensor and system components of  FIGS. 2-6 , in accordance with the method of the present invention. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Turning now to a more detailed description of the present invention,  FIGS. 1A-1C  illustrate a standard prior art rifle  10  in which the standard trigger assembly  20  and the standard stock  16  may be modified to provide the advantages of the system and method of the present invention. 
     In accordance with the method and structure of the present invention, rifle system  310  has a robust and reliable trigger assembly  50  which can be used to enhance the ergonomics of trigger actuation and allow the shooter or user to tune or customize the trigger for his or her needs while also aiding in the use of electro-optical and other accessories (e.g., S 1 -S 4 ) which may be mounted on or configured with the rifle system  310 . 
     Rifle system  310  has at least one trigger motion sensor (e.g.,  340 L,  340 R) which is proximate trigger assembly  50  when the receiver assembly  312  is installed in the stock (or chassis)  316 . Referring to the exemplary embodiment of  FIG. 6 , Stock  316  has an open trough or channel  324  which is bounded by opposing sidewalls in which are mounted sensor segments (e.g.,  340 L,  340 R) separated by the width of the open trough  324 , and each aligned to intersect a transverse motion sensing or sensor axis  330 . The trigger motion sensor (e.g.,  340 L,  340 R) is configured to sense (from a selected standoff distance, without contacting or interfering with the trigger assembly  50  in any way) at least one of (a) first stage movement or (b) actuation of safety lever  170 , and generate a “trigger motion sensed” signal in response. 
     The rifle system  310  and method of the present invention preferably includes installing a drop-in adjustable trigger assembly  50  comprising a housing having a first side plate and a second side plate which carry a pivoting bolt sear which is connected to a sear safety linkage. The housing has a sear safety linkage slot defined therein which guides the pivoting sear safety linkage in response to actuation of an upwardly projecting thumb safety lever&#39;s actuation. A trigger bracket  102  preferably carries a removable trigger shoe  100  and is configured to pivot within the housing about a pivot point positioned within the housing&#39;s lower portion. This trigger bracket preferably carries an adjustable rocker  130  having a first stage movement adjustment and a second stage length adjustment. The pivoting safety mechanism&#39;s safety linkage pivots rearwardly to push upon or cam a bolt sear upwardly, thus disengaging the bolt sear from the trigger sear. 
     Trigger assembly  50  is compact and robust, due in part to the configuration of the housing&#39;s parallel, planar left or first side plate and the second or right side plate which carry, orient and support the fixed and moving components of the assembly, including the pivoting safety lever which is rotatable about a transverse pin&#39;s axis from a forward “safety off” position to a rearward “safety on” position. The pivoting trigger bracket carries the adjustable transverse rocker member, which has an internal threaded bore that engages a rocker set screw to raise or lower the rocker, and the lower the rocker is positioned, the smaller the trigger&#39;s 1st stage take-up, because of an angled forward face on the pivoting trigger sear. As the transverse rocker moves down, the mechanical advantage is decreased, thus increasing the 2nd stage weight of pull. The housing also carries a transverse trigger sear pin which defines the pivot axis for the trigger sear. The trigger sear has a forward face on the forward side of the pivot and has its trigger sear engagement surface on the rearward side of the pivot. The trigger assembly&#39;s sideplates preferably define unobstructed openings or non-ferrous segments proximate the trigger bracket, the sear&#39;s engagement face, the trigger shoe and the safety lever. 
     The rifle or portable firearm assembly  310  is configured to work with user-actuable sensors and systems (e.g., S 1 -S 4 ) and includes a removable receiver assembly  312  including a receiver coaxially aligned with and attached to a barrel  314 , where the receiver is attached to and responsive to the trigger assembly  50 . Rifle system  310  has a stock or chassis having a middle section  324  defining a trough or channel adapted to removably receive the receiver assembly  170  and its trigger assembly  50 , and the stock or chassis middle section defines a lumen or cavity having a trigger motion sensing sidewall segment along the transverse motion sensing or sensor axis  330  which is configured proximate the trigger assembly  50  when the receiver is installed in the stock or chassis; where the stock or chassis is configured to receive and support the user-actuable sensors and systems (e.g., any of S 1 -S 4 ). The trigger motion sensing sidewall segment includes one or more trigger motion sensors (e.g.,  340 L and  3409 R) which are carried within the opposing sidewall segments on opposing sides separate from trigger assembly  50  and so do not physically contact or attach to the removable drop-in trigger assembly  50  as illustrated in  FIGS. 2-6 , where no part of the trigger motion sensors (e.g.,  340 L and  3409 R) are illustrated as being part of trigger assembly  50 . So every part of the trigger motion sensor system (e.g.,  340 L and  3409 R) is spaced from every component of the trigger assembly by a selected “clearance” distance (e.g., at least 0.5 mm) when the receiver  170  carrying trigger assembly  50  is installed in the stock or chassis. 
     In rifle system  310 , trigger assembly  50  comprises a housing incorporating first and second spaced wall plates, a trigger bracket pivotally mounted between the wall plates which is configured to pivot within the housing about a pivot point positioned within the housing and a trigger shoe carried by said trigger bracket which is configured to disengage a firing mechanism in response to a force applied by the shooter or user. The trigger assembly also includes a safety mechanism actuable by a safety lever mounted on the housing where the trigger assembly is configured to provide a first stage movement in response to a first force applied by a user and, if the user applies a second force greater than said first force, a second stage movement. 
     Since the trigger assembly sideplates define openings or non-ferrous segments proximate at least one of the trigger bracket, trigger shoe and safety lever, those trigger assembly sideplate openings or non-ferrous segments are aligned with at least one of the trigger bracket, said trigger shoe and said safety lever to define a transverse trigger motion sensing axis. The transverse trigger motion sensing axis is aligned to intersect the stock middle section&#39;s trigger motion sensor which is proximate said trigger assembly when said receiver is installed in said stock or chassis. The trigger motion sensor is configured to sense, from a selected standoff distance, without contacting or interfering the trigger assembly in any way, at least one of (a) first stage movement or (b) actuation of the safety lever, and generate a “trigger motion sensed” signal in response thereto for transmission to auxiliary accessories (e.g., such as one or more of scopes or sights S 1 -S 4 ). 
     In the exemplary embodiment illustrated in  FIGS. 2-7 , at least one of the trigger bracket  102 , trigger shoe  100  and safety lever  170  are made from steel or another magnetic flux focusing material, and the transverse trigger motion sensing axis  330  substantially intersects a Hall effect trigger motion sensor (e.g.,  340 L,  340 R) which does not physically contact or attach to the trigger assembly  50  and is instead spaced from every component of trigger assembly  50  by a selected “clearance” or trigger-to-sensor distance (e.g., at least 0.5 mm) when the receiver  170  is assembled or installed in the stock or chassis  316 . 
     Alternatively, the rifle or portable firearm assembly can include a trigger bracket, trigger shoe and said safety lever which are made from steel or another substantially opaque material, and the transverse trigger motion sensing axis  330  substantially intersects an optical sensor (e.g., positioned at  340 L,  340 R) which does not physically contact or attach to the trigger assembly and is instead spaced from every component of the trigger assembly by a selected trigger-to-sensor distance (e.g., at least 0.5 mm) when the receiver is installed in the stock or chassis. 
     Rifle or portable firearm assembly  310  include be a standard (e.g., Remington 700 style, M40 or M24) receiver, attached to and responsive trigger assembly  50  where the trigger motion sensor (e.g.,  340 L,  340 R) is configured to sense at least one of (a) first stage movement, (b) second stage movement or (c) actuation of the safety lever and generate a trigger motion sensed signal for the user-actuable sensors and systems (e.g., S 1 -S 4 ) in response. The rifle or portable firearm assembly of the present invention preferably has a stock or chassis with a bore axis extending along a longitudinal axis comprising a forward section adapted to receive a portion of the barrel (e.g.,  314 ) where the middle section is aligned with the forward section and adapted to receive the receiver when carrying trigger assembly  50 , where the stock or chassis middle section cavity trigger motion sensing sidewall segment is configured beside and proximate the trigger assembly when the receiver is installed in the stock or chassis. In the exemplary embodiment, the stock or chassis is configured with power and communication connections to provide power and communication between the trigger motion sensing sidewall segment&#39;s sensors (e.g.,  340 L,  340 R) and the user-actuable sensors and systems (e.g., S 1 -S 4 ). 
     In an alternative embodiment, an M110 style rifle (e.g.,  40 A or  40 B) is re-configured with a lower receiver including a standard trigger where the lower receiver  42  is altered to include at least one receive trigger motion sensor (e.g.,  340 L,  340 R) which senses trigger component motion without touching or interfering with the trigger assembly&#39;s mechanical components, in accordance with the method of the present invention. 
     Turning next to  FIGS. 2-5 , trigger mechanism  50  may be utilized the place of a prior art trigger assembly  20  for use in actuating a firing pin or striker mechanism as is found in a typical bolt assembly found in a standard rifle such as a Remington 700® brand bolt action rifle or M40 rifle  10 . Trigger assembly  50  of the present invention is generally illustrated  FIGS. 2-5 , to which reference is now made. As illustrated, the drop-in trigger assembly  50  has a housing  52  enclosing the assembly and having an upper portion  54 , a lower portion  56 , a forward portion  58 , and a rearward portion  60 , with the housing being formed by a first, or right-side wall plate  62  and a second or left-side wall plate  64 . As best seen in  FIG. 3 , wherein plate  62  is removed, and in  FIG. 6 , the housing  52  carries a pivoting bolt sear member  70  mounted on a bolt sear pin  72  extending between plates  62  and  64 . A pivoting sear safety linkage  74  is mounted between plates  62  and  64  and has an upper camming surface which engages a lower surface  78  of the pivoting bolt sear member  70 . The housing has opposed sear safety linkage slots  80  and  82  in plates  62  and  64 , respectively, which receive a lower pin  84  of linkage  74  to guide the pivoting sear safety linkage  74  in response to actuation of an upwardly projecting thumb safety linkage  90  actuated by a thumb safety lever  92 . 
     As illustrated, the trigger assembly  50  preferably includes a removable trigger shoe  100  beneath the housing which engages the bottom leg of a generally L-shaped trigger bar or bracket  102  which has an upwardly extending leg portion  104  pivotally mounted to a short pivot pin  108  which extends between and is supported by the housing plates  62  and  64  so that the trigger bracket  102  is configured to pivot within the housing  52  about the transverse axis of pivot pin  108  when trigger shoe  100  is pressed or squeezed by the shooter. An L-shaped trigger sear  110  having an upwardly and forwardly extending neck portion  112  is pivotally mounted on a safety pin  114  which extends through corresponding opposed apertures in housing plates  62  and  64  and is secured by suitable E-clips. The forwardmost end  115  of the trigger sear  110  is angled, or v-shaped, and engages an oval point set screw  116  threaded into an aperture  116 ′ on the rear surface of the upper end  104  of the trigger bracket  102 . The rearwardmost end  117  of the L-shaped trigger sear  110  incorporates a latching trough or edge  118  which receives and engages the lowermost end  119  of the pivoting bolt sear member  70 . 
     The upper portion  104  of the trigger bracket  102  carries on its right-hand surface a first rocker screw support  120  spaced from a second, lower rocker screw support  122  and the trigger bracket&#39;s spaced rocker screw supports  120  and  122  extend laterally through an opening in the housing plate  62  when the housing is assembled. The pair of spaced rocker screw supports  120  and  122  receive an adjustable transverse rocker  130  positioned according to the user&#39;s desire at a selected distance from the upper rocker support  120  by a rocker screw  132  which passes through a threaded internal bore  134  in rocker  130  and is secured by a set screw  136 , with a disc spring  138  at the bottom of the screw securing the screw in the bracket and urging the screw upwardly. An L-shaped rocker spring  140  engages the rocker at its upper end. The rocker preferably has a first stage movement adjustment and a second stage length adjustment. The rocker screw  132  and set screw  136  are adjustable to raise or lower the rocker to provide first stage trigger movement adjustment; the lower the rocker  130  is positioned, the smaller the trigger&#39;s 1st stage take-up, because of the angled forward face  112  on the pivoting trigger sear  110 . Furthermore, as the transverse rocker  130  moves down, the mechanical advantage of the trigger mechanism is decreased, thus increasing the 2 nd  stage weight required to fire, or increasing the force needed to cause the trigger to actuate or “break” (also known as the “weight of pull”). 
     The trigger bar or bracket  102  has a forward end which provides a trigger bracket distally projection member  106  ( FIGS. 3 and 6 ), and at the limit of the actuated movement of trigger bar or bracket  102 , trigger bracket distally projection member  106  bears upon or rests on a plunger  156  and an adjustable spring  154  captured in an upper shoulder portion  150  of a support element  152  which is a part of, or is secured to, the wall plate  62  and spans the distance between right plate  62  and the opposing left wall plate  64 . A spring  154  and a pin  156  extend through an aperture  158  of support element  152  and are adjustably secured therein by screw  160 , with the top of the pin abutting the lower surface of trigger stop  106 , to bias the trigger bar or bracket  102  in the unfired or rest position. 
     The pivoting safety mechanism  90 , as best seen in  FIG. 2 , includes a thumb safety linkage or lever  92  incorporating at its upper or distal end a knurled cylinder  170  secured by a screw  172  and at its lower or proximal end a connector plate  174  which pivotally mounts the lever  92  to the housing plate  62  by way of a safety lever pivot pin  176 . Safety pivot pin  176  passes through aperture  178  in connector plate  174  and apertures  180  and  182  in housing plates  62  and  64 , respectively, and is secured at opposite ends by E clips and  184  and  186 . A ball-detent safety tab  190  is mounted on pin  176  and is secured against the outer surface of the connector plate  174 , with a bottom flange  194  of the tab engaging a bottom edge  196  of the plate  174  so that the tab  190  rotates with the plate  174 . The tab provides a spring bias which bears against and secures a ball bearing  200  in an aperture  202  in safety connector plate  174 , the ball bearing extending through the aperture to serve as a detent that engages one or the other of spaced apart side plate apertures  204  or  206  to provide a positive “feel” as the safety mechanism  90  pivots between “on” or “off” positions. 
     The connector plate  174  also incorporates a safety linkage aperture  210  which is aligned with slot  80  in housing plate  62  and receives the lower pin  84  of pivoting sear safety linkage  74 , so that pivoting the thumb safety linkage lever  92  between on and off positions causes pin  84  to move back and forth in side plate slot  80  (and in its opposing slot  82  in housing plate  64 ). This motion causes the upper pin  212  of pivoting sear safety linkage  74  to move vertically in its corresponding vertical side plate slots  214  and  216  in housing plates  62  and  64 , respectively. 
     Mounted between an upper surface  220  of the L-shaped trigger sear  110  and a downwardly facing surface  222  of pivoting bolt sear member  70  is a spring-biased reset pin  224  surrounded by a spring  226 . The lower end of reset pin  224  is tapered and received in a depression  230  in upper surface  220  of the L-shaped trigger sear  110 . The reset pin spring  226  causes the L-shaped trigger sear  110  to reset after the trigger mechanism has been operated to fire a shot. 
     The components of trigger assembly  50  are preferably manufactured from steel, aluminum, or a similarly durable material, using wire EDM machining methods, laser cutting, CNC machining, forming presses or casting methods. The trigger mechanism  50  works by closing the bolt on a rifle or similar firearm which transfers firing pin spring force from the bolt assembly through a cocking piece&#39;s firing pin engagement surface which then bears upon to the upper engagement surface at the top of pivoting bolt sear member  70 , which projects from the top portion of housing  50 , as illustrated in  FIGS. 2-5 . With the trigger assembly of the present invention  50  installed in a firearm such as rifle  310  it will not fire until the cocking piece forces the bolt sear&#39;s upper engagement surface down and pivots the bolt sear  70  in a clockwise direction, as viewed in  FIG. 3 , sufficiently far to cause the distal tip  119  of bolt sear  70  to engage the latch  118  on the engagement surface of trigger sear  110  (best seen in  FIG. 3 ). The pivoting motion terminates when the upper end  76  of the sear safety linkage  74  presses against and engages bolt sear  70  at bolt sear lower bearing surface  78 , thus preventing the bolt sear from pivoting further under force from the bolt sear reset spring  226  and disengaging the bolt sear&#39;s distal tip  119  from the trigger sear&#39;s engagement surface  118 . The bolt sear  70  is thus configured to work with and actuate cocking piece  32  in a rifle&#39;s bolt assembly (e.g., as used in rifle  10  or  310 ). 
     Drop-in trigger assembly  50  is compact and robust, due in part to the configuration of the housing&#39;s right side plate  62  and left side plate  64 , which carry, orient and support the fixed and moving components of the assembly. Although not described, it will be evident from the exploded view of  FIG. 6  that numerous screws and pins extend between the side plates to secure the movable parts within or on the housing. These components include the pivoting safety linkage  90  and its thumb safety lever  92  which is rotatable about the axis of transverse pivot pin  176  from a forward “safety off” position to a rearward “safety on” position. Pivoting sear safety linkage  74  is driven by sear safety linkage pin  84 , which is transversely inserted in the safety lever connector plate aperture  210  which drives the lower end of the elongated pivoting sear safety linkage  74  forwardly or rearwardly in elongated housing slots  80  and  82  to cause the sear safety linkage&#39;s upper end  76  to be moved downwardly or upwardly, respectively, in slots  214  and  216  in response to safety linkage movement. 
     As described above, the internal threaded bore  134  of the pivoting transverse rocker  130  engages rocker screw  132  to raise or lower the rocker, and the lower the rocker is positioned, the smaller the trigger&#39;s 1st stage take-up distance, because rocker  130  then bears against the angled forward face  112  on the pivoting trigger sear  110 . The housing also carries the transverse trigger sear pivot pin or safety pin  114  which defines the pivot axis for the L-shaped trigger sear  110  and trigger sear  110  has its forward face  112  on the forward side of the pivot. Trigger sear  110  has its trigger sear engagement surface  118  on the rearward side of the pivot pin  114  ( FIG. 3 ). 
     In use, when the shooter moves the pivoting safety lever  92  from the rearward “safety on” position to the forward “safety off” position ( FIG. 19 ), the pivoting safety link&#39;s sear safety linkage pin  84  is shifted to its forward position in slots  80  and  82 , and the pivoting safety link&#39;s upper pin  212  is pulled down in its corresponding slots  214  and  216 . This disengages pivoting safety link  74  from the bolt sear&#39;s lower bearing surface  78 , thus allowing the bolt sear  70  to pivot counter-clockwise, under force from the bolt assembly&#39;s firing pin spring, when the rifle is fired. Bolt sear reset spring  226  will “reset” the bolt sear&#39;s distal tip  119  into engagement with the trigger sear&#39;s engagement surface  118  when the rifle&#39;s bolt is cycled. 
     When the shooter moves the pivoting safety lever from the forward “safety off” position to the rearward “safety on” position, the safety linkage pin  84  drives the lower end of pivoting safety link  74  rearwardly in the housing slots  80  and  82  so that the sear safety linkage&#39;s upper pin  212  pivots upwardly in slots  214  and  216 , pressing pivoting safety link&#39;s upper surface  76  against and engaging the lower bearing surface  78  of the bolt sear  70 . This prevents the bolt sear from pivoting under force from the cocked bolt assembly&#39;s firing pin spring (not shown) and disengages the bolt sear&#39;s distal tip  119  from the engagement surface  118  of the trigger sear  110 . In accordance with the present invention, when the user touches the trigger  100  or the safety lever  170 , a signal is generated to actuate the user&#39;s sighting or other systems with sensors (e.g., optical sights S 1 -S 4 ). 
     As noted above, trigger assembly  50  incorporates user adjustable controls for a first stage weight of pull, first stage travel or movement range, second stage break weight and second stage engagement length, each of which can be optimized separately for accurate shooting. In the illustrated embodiment of  FIGS. 2-5 , the trigger mechanism uses two springs, where first stage weight is adjusted by compressing spring  154  with adjustment screw  160 , which preferably has a spring constant of approximately 15.8 lbs per inch. Trigger reset spring  226  serves to reset the connection between the bolt sear and the trigger sear for firing the next shot and reset spring  226  is constrained and guided by reset pin  224  which engages bolt sear  70  on the pin&#39;s (upper) while end trigger sear  110  bears on reset spring  226  at the spring&#39;s lower end. Reset spring  226  preferably has a spring constant of approximately 29 lbs per inch. 
     It will be appreciated by persons of skill in the art that the trigger assembly  50 , when installed in a rifle (e.g.,  310 ), is actuated when trigger shoe  100  is pressed, which pivots trigger bracket  102  rearward about pivot pin  108  (clockwise in  FIG. 3 ), causing the trigger bar or bracket  102  to force rocker  130  rearwardly toward the forward surface  112  of trigger sear  110 . In response, trigger sear  110  pivots slightly (counterclockwise in  FIG. 3 ), reducing the 2 nd  stage engagement overlap between edges  118  and  119  to just a few thousandths of an inch (e.g., 0.002-0.005 in). At some point during this rearward travel, trigger bracket  102  stops pivoting rearwardly because rocker  130  has engaged the trigger sear  110 , thus ending the length of the 1 st  stage of trigger pull. As the shooter or marksman continues to increase trigger pressure on trigger shoe  100 , the rocker  130  begins rotating the trigger sear  110 , until the last few thousandths of an inch of overlapping engagement length of its latching edge  118  is free of engagement with surface  119  of the bolt sear  70 , thus breaking contact and enabling trigger actuation in that instant. In response to this release, the bolt sear  70  pivots forward and down (clockwise in  FIG. 3 ), releasing cocking piece  32  in bolt assembly  30  to drive the firing pin (not shown) into the cartridge, firing the rifle. The first stage weight for trigger assembly  50  is adjustable by the control or set screw  116  independently of the first stage length of travel, which is controlled by the rocker vertical position adjustment screw  132 . The second stage weight is adjusted, in part, by the rocker adjustment screw  132  on the trigger bracket&#39;s side which moves rocker  130  up and down, changing its mechanical advantage. The second stage length of engagement is adjusted by the control screw or adjustment set screw  116  which is threaded into a bore  116 ′ inside the upper end  104  of the trigger bracket  102  that defines the distal surface to push on the very upper end of the front surface  115  of trigger sear  110 , pivoting it away from the bolt sear to set the “crisp” break (or actuation sensation) of trigger assembly  50 . The second stage weight is also adjusted by the spring  154  and its adjustment screw  160 , which oppose the rotation of the trigger bracket  102 . Trigger assembly  50  thus has adjustable first stage length of pull, first stage weight, second stage length of pull and second stage weight. The total weight is the sum of first stage weight and second stage weight and is adjustable from 8 ounces to three and one half pounds. Using these adjustments, the trigger first stage weight and second stage weight can be adjusted by the user for to achieve, for example, a total weight of 30 ounces where either the first stage weight is 5 ounces (meaning the second stage weight is a relatively heavy 25 ounces) or where the first stage weight is 25 ounces (meaning the second stage weight is a relatively light 5 ounces). 
     The safety mechanism consists of thumb safety linkage  90  which cams pivoting safety link  74  past top dead center, pushing upward on the bolt sear  70  and locking it in place, while simultaneously disengaging from the trigger sear  110 . The ball detent mechanism ( 190 ,  200  and apertures  204  and  206 ) captures the safety linkage  90  and keeps it in place, providing an audible and tactile “click” sensation of positive control for the shooter. The pivoting safety link or sear safety linkage  74  and thumb safety linkage  90  comprise a “two-bar linkage” which cooperate to provide large mechanical advantage but require small safety actuating force from the user, and an “overcamming” action provided by the travel of sear safety linkage  74  in the slots of housing plates  62  and  64  serves as a failsafe adapted to prevent accidental release of the bolt assembly&#39;s firing pin and discharge. When the safety is on the sear safety linkage  74  engages the bottom surface  78  of bolt sear  102 , pivoting it up (clockwise in  FIG. 6 ) to disengage it from the trigger sear  110  and preventing it from rotating to fire the firearm. The illustrated trigger assembly  50  is adaptable for use with a left hand side safety lever which projects downwardly into the area proximate the trigger shoe. 
     Persons of skill in the art will appreciate that the system and method of the present invention makes available a Non-Contact Electro-Magnetic Actuator system configured for use in a firearm assembly (e.g.,  310 ) configured to work with user-actuable systems with sensors (e.g., optical sights S 1 -S 4 ), where a non-contacting sensor can be used to enable, energize or actuate the red dot, illuminated reticle, ranging reticle or system or other accessories incorporated in the attached systems with sensors (e.g., optical sights S 1 -S 4 ). Once the trigger assembly or component motion is detected, an “energize” or “actuate” signal is generated (e.g., in response to sensing motion of the trigger  100  or safety lever  170 ) and that actuation signal may be transmitted wirelessly (e.g., by Bluetooth) or by a wired connection (not shown) to the systems with sensors (e.g., optical sights S 1 -S 4 ). The system of the present invention (in the exemplary illustrated embodiment comprises a receiver assembly  312  attached to and responsive to a trigger assembly  50  is configured with a stock or chassis  316  having a middle section  324  that defines a lumen or cavity having a trigger motion sensing sidewall segment which is configured proximate said trigger assembly, wherein said stock or chassis is configured to receive, support and operate with the user-actuable systems with sensors (e.g., optical sights S 1 -S 4 ). Preferably the trigger motion sensing sidewall segment includes a trigger motion sensor (e.g.,  340 L,  340 R) which does not physically contact or attach to said trigger assembly and is instead spaced from every component of said trigger assembly by a selected trigger-to-sensor distance when said receiver is installed in said stock or chassis. 
     Having described preferred embodiments of a new and improved trigger assembly structure and method, it is believed that other modifications, variations and changes will be suggested to those skilled in the art in view of the teachings set forth herein. It is therefore to be understood that all such variations, modifications and changes are believed to fall within the true spirit and scope of the present invention as defined by the following claims.