Abstract:
An improved trigger system for lever action rifles that utilize a trigger block safety, comprising a trigger, sear, bushing and springs. The trigger, sear, bushing and springs are assembled as one unit permitting the user to fit the trigger system into an existing rifle without modification. The system eliminates looseness, play, creep and drag found in existing systems.

Description:
FEDERALLY SPONSORED RESEARCH  
         [0001]    Not Applicable  
         SEQUENCE LISTING  
         [0002]    Not Applicable  
         BACKGROUND  
         [0003]    1. Field of Invention  
           [0004]    This invention relates to trigger systems for rifles, specifically, such systems which are used in lever action or single shot rifles with trigger block safeties.  
           [0005]    2. Description of Prior Art  
           [0006]    Historically and through the present time, in simplest form, the fire control mechanism of firearms has consisted of a hammer mechanism powered by a spring which serves to strike the igniting charge, together with a trigger mechanism, which releases the hammer. Illustrative examples of the traditional hammer/trigger mechanism in lever action repeating rifles are found in Hepburn, U.S. Pat. Nos. 298,377, 371,455 and 502,489. As can be seen from the foregoing designs, the trigger itself is a one piece unit that pivots back and forth on a pin and is held in place against the hammer cocking surfaces by a spring resting on a flat on the upper backside of the trigger. When the hammer is in the fired or uncocked position, the trigger nose rests on the cocking surfaces of the hammer. As the hammer is cocked, the trigger nose presses itself against the hammer surface via spring pressure against the trigger. The trigger nose continues riding past the safety or half cock notch on the cocking surfaces of the hammer until it reaches the full cock notch. At that time the trigger nose locks into place by spring pressure on the trigger. When the trigger is pulled, the trigger nose slides out of the full cock notch, the hammer drops, and the spring pressure on the trigger causes the trigger to rest again against the hammer cocking surfaces.  
           [0007]    The foregoing trigger/hammer mechanism was improved by Hepburn in U.S. Pat. No. 434,062. The improvement, commonly known as a “trigger block safety” changed the one piece trigger into a combination of a separate trigger and a separate trigger nose, which part is commonly known as a sear. The trigger has a flat on the upper backside with an extension connection on the upper portion that allows the sear to be fitted by way of a slot in the sear body. Both parts fitted together pivot on a pin, so that when the hammer is in the fired or uncocked position, the sear rides against the cocking surfaces of the hammer by way of the pressure from the trigger derived from the trigger spring. As the hammer is cocked, the sear continues to ride against the cocking surfaces of the hammer, held in place by trigger pressure, until the full cock notch is reached. At that time the sear rests in the full cock notch until the trigger is pulled, which drops the sear from the notch causing the hammer to fall. The separate trigger permits a block to be fitted so as to prevent full travel of the trigger and concomitant actuation of the sear against the hammer until such time as the lever actuation mechanism and breech block are fully closed, thereby moving the safety block into a position allowing full travel of the trigger.  
           [0008]    Hepburn&#39;s lever action repeating rifles with trigger block safeties continue to be manufactured today. While such triggers provide a means to ensure that the rifle is not fired until the breech is closed and the action fully locked they suffer from a number of disadvantages, specifically:  
           [0009]    a. excessive side play or movement of the trigger in the trigger/sear combination;  
           [0010]    b. excessive movement fore and aft of the trigger in the trigger/ sear combination;  
           [0011]    c. excessive movement of the trigger prior to firing (creep);  
           [0012]    d. excessive pressure on the trigger necessary to disengage the sear.  
         OBJECTS AND ADVANTAGES  
         [0013]    The objects and advantages of the present invention are:  
           [0014]    a. to provide a trigger mechanism which allows use of the trigger block safety and eliminates excessive side to side play of the trigger in the firearm;  
           [0015]    b. provide a trigger mechanism which allows use of the trigger block safety and eliminates excessive trigger movement fore and aft;  
           [0016]    c. to provide a trigger mechanism which allows use of the trigger block safety while eliminating excessive creep;  
           [0017]    d. to provide a trigger mechanism which allows use of the trigger block safety while eliminating the excessive pressure necessary to disengage the sear.  
           [0018]    Further objects and advantages will become apparent from a consideration of the ensuing description and drawings.  
         DRAWINGS  
       Drawing Figure  
         [0019]    FIGS.  1 ,  1 -A to  1 -C shows the various views of the trigger portion of the trigger system  
           [0020]    FIGS.  2 ,  2 -A to  2 -C shows the various views of the bushing portion of the trigger system.  
           [0021]    FIGS.  3 ,  3 -A to  3 -C shows the various views of the sear portion of the trigger system  
           [0022]    [0022]FIG. 4 shows the sear placement spring portion of the trigger system.  
           [0023]    [0023]FIG. 5 shows the assembled trigger system, referenced to the hammer.  
           [0024]    [0024]FIG. 6 shows the assembled trigger system installed in the firearm. 
       
    
    
     Reference Numerals in Drawings  
       [0025]    [0025]                                                8   Trigger   10   Trigger/Sear connector       12   Trigger through hole   14   Bushing through hole       16   Sear through hole   18   Sear connector slot       20   Bushing surface   22   Sear body       24   Trigger flat   26a   Sear placement spring hole       26b   Sear placement spring hole                    
       DETAILED DESCRIPTION  
       [0026]    The trigger system is manufactured from any high quality steel in three separate parts. The three are the Trigger, shown in various views in FIGS.  1 ,  1 -A through  1 -C; the Bushing, shown in various views in FIGS.  2 ,  2 -A through  2 -C: and the Sear, shown in various views in FIGS.  3 ,  3 -A through  3 -C.  
         [0027]    The trigger body  8  itself in FIG. 1-A side view and FIGS.  1 -B and  1 -C front and back view is of traditional curved design to permit rearward manipulation by the shooting finger. The trigger body is designed to accept the bushing at  12 , the trigger through hole, which is precision machined through  10 , the trigger sear connector, to accommodate the bushing via a press fit. The trigger/sear connector  10  is beveled or rounded to the same dimensions as the top of the sear body  22 , as in FIGS.  1 -A and  3 -A. The bushing surface  20  in FIGS. 2 and 2-B side view is machined to precisely fit into the trigger through hole  12  and the sear through hole  16  when assembled. The bushing through hole  14  in FIG. 2-B front view is machined to permit insertion of a pin to hold the entire assembly in place.  
         [0028]    The sear body  22  in FIG. 3-A side view has a machined sear through hole  16 . The sear connector slot  18  in FIG. 3-B top view and  3 -C bottom view is machined to accept the trigger/sear connector. Sear body placement spring holes  26   a  and  26   b  in bottom view FIG. 3-C are machined to accept the sear placement spring, FIG. 4.  
         [0029]    To assemble the system, the sear placement springs FIG. 4 fit into the sear placement spring holes  26   a  and  26   b  in the sear body  22 . The sear connector  10  on the trigger body  8  is fitted inside the sear body  22  by means of the sear connector slot  18 , so that the sear placement springs are exerting pressure on both the trigger body  8  and the sear body  22  at the trigger flat  24 . The parts as thus assembled are held in place as one unit when the FIG. 2 bushing is pressed through the trigger through hole  12 , which is riding inside the sear through hole  16 . The assembled mechanism is shown in perspective to the hammer in FIG. 5.  
       Advantages  
       [0030]    From the description, above, a number of advantages of the present invention become evident.  
         [0031]    1. The rounding of the trigger/sear connector to the same dimensions of the sear body allows more precise alignment of the trigger system parts when assembled and eliminates any drag or interference on the hammer of the firearm while the mechanism goes through the cocking/firing cycle.  
         [0032]    2. The use of a bushing to hold all parts in place allows for precision assembly of the separate trigger and sear thereby eliminating side play, vertical play, looseness and binding or drag on the sear.  
         [0033]    3. The close fit of parts that is made possible by use of a separate bushing eliminates creep and excessive pressure necessary to release the hammer.  
         [0034]    4. The use of the placement springs provides upward and downward spring pressure on the sear and trigger thereby eliminating uncontrolled fore and aft trigger movement  
       Operation  
       [0035]    The operation of the trigger system designed here is similar to those presently in use and accordingly, can be used to replace the systems presently in use without modification to the firearm merely by removing the old system and reinstalling the new system on an existing trigger/sear pin. Rearward pressure on the trigger body  8  causes the sear body  22  to pivot forward around the trigger/sear pin thereby moving the sear out of the full cock notch, allowing the hammer to go forward. Unlike present systems, the sear body  22  pivots while assembled into the trigger body  8  via the trigger through hole  16  and the bushing, so that the sear body and the bushing move as one unit.  
       Conclusion, Ramification and Scope  
       [0036]    Accordingly, the reader will see that the Safety Precision Trigger System is easily installed into currently produced firearms that utilize the trigger block safety as designed by Hepburn in U.S. Pat. No. 434,062. The Safety Precision Trigger System allows use of the trigger safety while controlling fore and aft play of the trigger body, with the added advantage that trigger creep and trigger pull are reduced.  
         [0037]    Although the description above contains many specificities, these should not be construed as limiting the scope of the invention. Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.