WO2018231499A1

WO2018231499A1 - Rifle receivers and top cover

Info

Publication number: WO2018231499A1
Application number: PCT/US2018/034557
Authority: WO
Inventors: Eric Belanger
Original assignee: Nsk Arms Inc.
Priority date: 2017-06-15
Filing date: 2018-05-25
Publication date: 2018-12-20
Also published as: WO2018231326A1

Abstract

A firearm comprises an upper receiver. The upper receiver defines a passage adapted to receive a reciprocating bolt. The passage defines a primary axis. The firearm comprises a lower receiver removably connected to the upper receiver. The lower receiver includes a trigger mechanism. The firearm comprises a hammer pivotally connected to the upper receiver and movable between a retracted position and a forward position. The firearm comprises a hammer spring operably interconnecting the lower receiver and the hammer and adapted to bias the hammer toward the forward position. The upper receiver has a first elongated mating facility parallel to the primary axis. The lower receiver has a second elongated mating facility parallel to the primary axis and adapted to mate with the first elongated mating facility to prevent relative displacement and motion between the upper receiver and the lower receiver except in a direction parallel to the primary axis.

Description

RIFLE RECEIVERS AND TOP COVER

Cross-Reference to Related Application

[0001] This application claims the benefit of U.S. Provisional Application No.: 62/601,855, filed 06/15/2017, which is hereby incorporated by reference in its entirety.

Field of the Present Disclosure

[0002] The present disclosure generally relates to firearms and more specifically to firearm receivers and top covers for short carbine rifles.

Background of the Present Disclosure

[0003] Many rifle receivers are not adapted to quickly and easily clear trigger malfunctions in the field. Many rifles have trigger mechanisms that are not easily accessible. Many trigger mechanisms are not adapted to be operated with gloves, especially gloves employed during cold weather. Many rifle receivers are not adapted to attach a stock inline or above the centerline of the rifle. Many rifle receivers do not comprise an integrated magazine well. Many rifle receivers are not adapted for easy change of rifle barrels. What is needed are improved rifle receivers.

[0004] Many rifles equipped with a top cover (also known as a receiver cover or dust cover) may not be adapted to clear some malfunctions without completely removing the top cover from the rifle. With the top cover removed, it may be more likely to be dropped and/or damaged. A user holding a removed top cover may limit the use of two hands to clear some malfunctions. Many receivers and top covers may not be adaptable for easy release of the top cover from the receiver. Many top covers may not comprise an integrated accessory rail. Many top covers may not be adapted to permit charging handles to be employed on either side of the bolt carrier. What is needed is an improved top cover.

Summary of the Present Disclosure

[0005] At least some embodiments of the present disclosure provide a firearm. The firearm comprises an upper receiver. The upper receiver defines a passage adapted to receive a reciprocating bolt. The passage defines a primary axis. The firearm comprises a lower receiver removably connected to the upper receiver. The lower receiver includes a trigger mechanism. The firearm comprises a hammer pivotally connected to the upper receiver and movable between a retracted position and a forward position. The firearm comprises a hammer spring operably interconnecting the lower receiver and the hammer and adapted to bias the hammer toward the forward position. The upper receiver has a first elongated mating facility parallel to the primary axis. The lower receiver has a second elongated mating facility parallel to the primary axis and adapted to mate with the first elongated mating facility to prevent relative displacement and motion between the upper receiver and the lower receiver except in a direction parallel to the primary axis.

[0006] The first elongated mating facility and the second elongated mating facility may

include elongated tabs and channels.

[0007] At least a first one of the first elongated mating facility and the second elongated

mating facility may include a dovetail element.

[0008] The first elongated mating facility may define a channel facing laterally away from the upper receiver.

[0009] The second elongated mating facility may include an elongated tab adapted to be

closely and slideably received in the channel.

[0010] One of the first elongated mating facility and the second elongated mating facility may include opposed channels facing in opposed directions. The other of the first elongated mating facility and the second elongated mating facility may include opposed tabs facing in opposed directions. The opposed tabs may be adapted to be slideably received in the opposed channels.

[0011] One of the first elongated mating facility and the second elongated mating facility may include a first pair of opposed tabs extending toward each other. The other of the first elongated mating facility and the second elongated mating facility may include a second pair of opposed tabs extending away from each other. The second pair of opposed tabs may be adapted to engage the first pair.

[0012] The first elongated mating facility may include a forward stop at a forward end. The first elongated mating facility may include a selected first profile extending to a rear free end. The second elongated mating facility may include a rear stop at a rear end. The second elongated mating facility may include a selected second profile extending to a forward free end, such that the lower receiver may be connected to the upper receiver from the rear end and slid forward to a stop position.

[0013] The upper receiver may define a magazine well forward of the lower receiver.

[0014] The hammer spring may have an active position in which a first hammer portion of the hammer spring is connected to the lower receiver and a second hammer portion of the hammer spring is connected to the hammer to bias the hammer toward the forward position. The hammer spring may have an inactive condition in which the first hammer portion is connected to the hammer and the lower receiver is removable from the upper receiver.

[0015] The hammer spring may have an intermediate portion contacting the hammer. The hammer spring may have opposed end portions each adapted to contact the lower receiver to bias the hammer. The opposed end portions may be adapted to engage the hammer to enable removal of the lower receiver from the upper receiver.

[0016] At least some embodiments of the present disclosure provide a firearm. The firearm comprises a frame. The firearm comprises an elongated top cover having a forward end pivotally connected to the frame. The elongated top cover has a latch engagement facility at a rear end. The rear end is opposed to the forward end. The firearm comprises a latch connected to the frame. The latch is operable to reciprocate between a forward released position and a rearward latched position. The latch is spring biased to the rearward latched position. The elongated top cover is movable between an open position in which the rear end is away from the frame, and a closed position in which the rear end is adjacent the frame. The latch has a cam surface operable to move the latch in the forward direction in response to movement of the elongated top cover toward the closed position. The latch engagement facility has an engagement surface adapted to contact a ledge surface of the latch when the elongated top cover is in the closed position. The firearm comprises an actuator connected to the elongated top cover and operable to reciprocate between a rest position and a pressed position with respect to the elongated top cover. The actuator has a rear portion with an exposed actuation surface and a forward portion having a latch actuation surface adjacent the latch when the elongated top cover is in the closed position.

[0017] The elongated top cover may define an aperture. The actuator may be received in the aperture.

[0018] The actuator may be spring biased to the rest position.

[0019] The actuator may be an elongated actuator body defining an actuator axis.

[0020] The latch actuation surface may be angled with respect to the actuator axis.

[0021] The latch actuation surface may face in a direction forward and downward.

[0022] The actuator may define a slot. The elongated top cover may include a limit pin

received in the slot.

[0023] The actuator may define an elongated bore receiving an actuator spring.

[0024] The elongated bore may be open at a forward end. The actuator spring may be a coil spring. Brief Description of the Drawings

[0001] FIG. 1 illustrates an example lower receiver and an example upper receiver of an

example firearm according to various aspects of an embodiment.

[0002] FIGs. 2A and 2B illustrate side views of example lower receivers and example upper receivers of example firearms according to various aspects of various embodiments.

[0003] FIGs. 3A and 3B illustrate cross-sectional views of example lower receivers and

example upper receivers of example firearms according to various aspects of various embodiments.

[0004] FIGs. 4 A and 4B illustrate top views of example lower receivers and example upper receivers of example firearms according to various aspects of an embodiment.

[0005] FIGs. 5A, 5B, and 5C illustrate angled views of example lower receivers and example upper receivers of example firearms according to various aspects of an embodiment.

[0006] FIG. 6 illustrates an example lower receiver removed from an example upper receiver of an example firearm according to various aspects of an embodiment.

[0007] FIG. 7 illustrates an example lower receiver partially mated to an example upper

receiver of an example firearm according to various aspects of an embodiment.

[0008] FIG. 8 illustrates an example lower receiver fully mated to an example upper receiver of an example firearm according to various aspects of an embodiment.

[0009] FIG. 9 illustrates an example lower receiver fully secured to an example upper receiver of an example firearm according to various aspects of an embodiment.

[0010] FIG. 10A illustrates a side view of an example lower receiver removed from an

example upper receiver of an example firearm according to various aspects of an embodiment.

[0011] FIG. 10B illustrates a side view of an example lower receiver partially mated to an example upper receiver of an example firearm according to various aspects of an embodiment.

[0012] FIG. 11 illustrates a cross-sectional view of an example lower receiver partially mated to an example upper receiver of an example firearm according to various aspects of an embodiment.

[0013] FIGs. 12 A and 12B illustrate views of example first elongated mating facilities and example second elongated mating facilities of example firearms according to various aspects of an embodiment. [0014] FIG. 13 illustrates a cross-sectional view of an example first elongated mating facility and an example second elongated mating facility of an example firearm according to an aspect of an embodiment.

[0015] FIGs. 14 A and 14B illustrate top cutaway views of example first elongated mating facilities and example second elongated mating facilities of example firearms according to various aspects of an embodiment.

[0016] FIG. 15A illustrates an example lower receiver according to various aspects of an embodiment.

[0017] FIG. 15B illustrates an exploded view of an example lower receiver according to

various aspects of an embodiment.

[0018] FIGs. 16A and 16B illustrate example elongated top covers of example firearms

according to various aspects of various embodiments.

[0019] FIG. 17 illustrates a side view of an example elongated top cover of an example

firearm according to various aspects of an embodiment.

[0020] FIG. 18 illustrates an example latch installed on an example firearm according to

various aspects of an embodiment.

[0021] FIG. 19 illustrates an example elongated top cover according to an aspect of an

embodiment.

[0022] FIG. 20A illustrates a cross-sectional view of an example elongated top cover that is fully latched to an example frame of an example firearm according to various aspects of an embodiment.

[0023] FIG. 20B illustrates a cross-sectional view of an example elongated top cover with a partially depressed actuator of an example firearm according to various aspects of an embodiment.

[0024] FIG. 21 illustrates a cross-sectional view of an example elongated top cover that is unlatched from an example frame of an example firearm according to an aspect of an embodiment.

[0025] FIG. 22 illustrates a cross-sectional view of an example elongated top cover in a

partially open position on an example firearm according to an aspect of an embodiment.

[0026] FIG. 23 illustrates a cross-sectional view of an example elongated top cover engaged with an example latch of an example firearm during closing of the elongated top cover according to an aspect of an embodiment.

[0027] FIG. 24 illustrates an exploded view of an example elongated top cover according to an aspect of an embodiment. Description of the Current Embodiments

[0028] Embodiments of the present disclosure now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the present disclosure are shown. This present disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure. Like numbers refer to like elements throughout.

[0029] Certain embodiments of the present disclosure provide a firearm.

[0030] FIG. 1 illustrates an example lower receiver 4 and an example upper receiver 2 of an example firearm 100 according to various aspects of an embodiment. The lower receiver 4 may comprise a trigger mechanism 6. The trigger mechanism 6 may be connected to the lower receiver 4 through employment of a trigger pin 56. The lower receiver 4 may comprise at least one safety selector 40. The lower receiver 4 may comprise a grip 46. The upper receiver 2 may comprise a hammer 8. The hammer 8 may be pivotally connected to the upper receiver 2 through employment of a hammer pin 58. The upper receiver 2 may comprise a takedown pin 44. The takedown pin 44 may be employed to secure the lower receiver 4 when fully connected to the upper receiver 2.

[0031] FIG. 2A illustrates a side view of an example lower receiver 4 and an example upper receiver 2 of an example firearm 200 according to various aspects of an embodiment. The lower receiver 4 may comprise a trigger mechanism 6. The trigger mechanism 6 may be connected to the lower receiver 4 through employment of a trigger pin 56. The lower receiver 4 may comprise at least one safety selector 40. The lower receiver 4 may comprise a grip 46. The upper receiver 2 may comprise a hammer 8. The hammer 8 may be pivotally connected to the upper receiver 2 through employment of a hammer pin 58. The hammer 8 may be movable between a retracted position and a forward position. The upper receiver 2 may comprise a hammer spring 10. The hammer spring 10 may operably interconnect the lower receiver 4 and the hammer 8. The hammer spring 10 may be adapted to bias the hammer 8 toward the forward position, as shown. The hammer spring 10 may have an inactive condition as shown. The upper receiver 2 may comprise a takedown pin 44. The takedown pin 44 may be employed to secure the lower receiver 4 when fully connected to the upper receiver 2. [0032] FIG. 2B illustrates a side view of an example lower receiver 4 and an example upper receiver 2 of an example firearm 201 according to various aspects of an embodiment. The lower receiver 4 may comprise a trigger mechanism 6. The trigger mechanism 6 may be connected to the lower receiver 4 through employment of a trigger pin 56. The lower receiver 4 may comprise at least one safety selector 40. The lower receiver 4 may comprise a grip 46. The upper receiver 2 may comprise a hammer 8. The hammer 8 may be pivotally connected to the upper receiver 2 through employment of a hammer pin 58. The hammer 8 may be movable between a retracted position and a forward position. The upper receiver 2 may comprise a hammer spring 10. The hammer spring 10 may operably interconnect the lower receiver 4 and the hammer 8. The hammer spring 10 may be adapted to bias the hammer 8 toward the forward position, as shown. The upper receiver 2 may comprise a takedown pin 44. The takedown pin 44 may be employed to secure the lower receiver 4 when fully connected to the upper receiver 2.

[0033] FIG. 3A illustrates a cross-sectional view of an example lower receiver 4 and an

example upper receiver 2 of an example firearm 300 according to various aspects of an embodiment. The lower receiver 4 may comprise a trigger mechanism 6. The trigger mechanism 6 may be connected to the lower receiver 4 through employment of a trigger pin 56. The lower receiver 4 may comprise a safety selector body 42. The lower receiver 4 may comprise a grip 46. The upper receiver 2 may comprise a hammer 8. The hammer 8 may be pivotally connected to the upper receiver 2 through employment of a hammer pin 58. The hammer 8 may be movable between a retracted position and a forward position. The upper receiver 2 may comprise a hammer spring 10. The hammer spring 10 may operably interconnect the lower receiver 4 and the hammer 8. The hammer spring 10 may be adapted to bias the hammer 8 toward the forward position, as shown. The hammer spring 10 may have an inactive condition as shown. The upper receiver 2 may comprise a takedown pin 44. The takedown pin 44 may be employed to secure the lower receiver 4 when fully connected to the upper receiver 2. The upper receiver 2 may define a magazine well 30 forward of the lower receiver 4.

[0034] FIG. 3B illustrates a cross-sectional view of an example lower receiver 4 and an

example upper receiver 2 of an example firearm 301 according to various aspects of an embodiment. The lower receiver 4 may comprise a trigger mechanism 6. The trigger mechanism 6 may be connected to the lower receiver 4 through employment of a trigger pin 56. The lower receiver 4 may comprise a safety selector body 42. The lower receiver 4 may comprise a grip 46. The upper receiver 2 may comprise a hammer 8. The hammer 8 may be pivotally connected to the upper receiver 2 through employment of a hammer pin 58. The hammer 8 may be movable between a retracted position and a forward position. The upper receiver 2 may comprise a hammer spring 10. The hammer spring 10 may operably interconnect the lower receiver 4 and the hammer 8. The hammer spring 10 may be adapted to bias the hammer 8 toward the forward position, as shown. The hammer spring 10 may have an active position, as shown. The upper receiver 2 may comprise a takedown pin 44. The takedown pin 44 may be employed to secure the lower receiver 4 when fully connected to the upper receiver 2. The upper receiver 2 may define a magazine well 30 forward of the lower receiver 4.

[0035] FIG. 4A illustrates a top view of an example lower receiver 4 and an example upper receiver 2 of an example firearm 400 according to an aspect of an embodiment. The lower receiver 4 may comprise at least one safety selector 40. The lower receiver 4 may comprise a safety selector body 42. The lower receiver 4 may comprise a trigger pin 56. The upper receiver 2 may comprise a hammer 8. The hammer 8 may be pivotally connected to the upper receiver 2 through employment of a hammer pin 58. The hammer 8 may be movable between a retracted position, as shown, and a forward position. The upper receiver 2 may comprise a hammer spring. The hammer spring may have an active position, as shown. A first hammer portion 32 of the hammer spring may be connected to the lower receiver 4 as shown. A second hammer portion 34 of the hammer spring may be connected to the hammer 8 as shown.

[0036] FIG. 4B illustrates a top view of an example lower receiver 4 and an example upper receiver 2 of an example firearm 401 according to an aspect of an embodiment. The illustration of firearm 401 is similar to the illustration of firearm 400 except that in firearm 401, the selector body 42 of firearm 400 has been removed for illustration.

[0037] FIGs. 5A, 5B, and 5C illustrate angled views of an example lower receiver 4 and an example upper receiver 2 of example firearms (500, 501, and 502) according to various aspects of an embodiment. In FIG. 5A, firearm 500 is angled upward towards the right side of the firearm 500. In FIG. 5B, firearm 501 is angled downward towards the left side of the firearm 501. In FIG. 5C, firearm 502 is angled forward (forward portion down). The lower receiver 4 may comprise at least one safety selector 40. The lower receiver 4 may comprise a trigger pin 56. The upper receiver 2 may comprise a hammer 8. The hammer 8 may be pivotally connected to the upper receiver 2 through employment of a hammer pin 58. The upper receiver 2 may comprise a hammer spring. The hammer spring may comprise an intermediate portion 34 contacting the hammer 8. The hammer spring may comprise opposed end portions 32. Each of the opposed end portions 32 may be adapted to contact the lower receiver 4 to bias the hammer 8. The opposed end portions 32 may be adapted to engage the hammer 8 to enable removal of the lower receiver 4 from the upper receiver 2 as shown in FIGs. 2A and 3A.

[0038] FIG. 6 illustrates an example lower receiver 4 removed from an example upper

receiver 2 of an example firearm 600 according to various aspects of an embodiment. The upper receiver 2 may define a passage adapted to receive a reciprocating bolt. The passage may define a primary axis. The upper receiver 2 may comprise a first elongated mating facility 12. The first elongated mating facility 12 may be parallel to the primary axis. The first elongated mating facility 12 may comprise a forward stop at a forward end 22. The first elongated mating facility 12 may comprise a selected first profile extending to a rear free end 24. The upper receiver 2 may comprise a hammer 8. The hammer 8 may be pivotally connected to the upper receiver 2 through employment of a hammer pin 58. The upper receiver 2 may comprise a hammer spring. The hammer spring may comprise a first hammer portion 32. The hammer spring may have an inactive condition in which the first hammer portion 32 is connected to the hammer 8. The hammer spring may have an inactive condition in which the lower receiver 4 is connectable to the upper receiver 2. The hammer spring may have an inactive condition in which the lower receiver 4 is removable from the upper receiver 2. The upper receiver 2 may comprise a takedown pin 44. The takedown pin 44 may be employed to secure the lower receiver 4 when fully connected to the upper receiver 2.The lower receiver 4 may comprise a second elongated mating facility 14. The second elongated mating facility 14 may be parallel to the primary axis. The second elongated mating facility 14 may be adapted to mate with the first elongated mating facility 12. The second elongated mating facility 14 may be adapted to mate with the first elongated mating facility 12 to prevent relative displacement and motion between the upper receiver 2 and the lower receiver 4 except in a direction parallel to the primary axis. The second elongated mating facility 14 may comprise a rear stop at a rear end 26. The second elongated mating facility 14 may comprise a selected second profile extending to a forward free end 28, such that the lower receiver 4 may be connected to the upper receiver 2 from the rear end and slid forward to a stop position. The lower receiver 4 may comprise a trigger mechanism 6. The trigger mechanism 6 may be connected to the lower receiver 4 through employment of a trigger pin 56. The lower receiver 4 may comprise at least one safety selector 40. The lower receiver 4 may comprise a grip 46.

[0039] FIG. 7 illustrates an example lower receiver 4 partially mated to an example upper receiver 2 of an example firearm 700 according to various aspects of an embodiment. The upper receiver 2 may comprise a first elongated mating facility 12. The upper receiver 2 may comprise a hammer 8. The hammer 8 may be pivotally connected to the upper receiver 2 through employment of a hammer pin 58. The upper receiver 2 may comprise a hammer spring. The hammer spring may comprise a first hammer portion 32. The hammer spring may have an inactive condition in which the first hammer portion 32 is connected to the hammer 8. The hammer spring may have an inactive condition in which the lower receiver 4 is connectable to the upper receiver 2. The hammer spring may have an inactive condition in which the lower receiver 4 is removable from the upper receiver 2. The upper receiver 2 may comprise a takedown pin 44. The takedown pin 44 may be employed to secure the lower receiver 4 when fully connected to the upper receiver 2. The lower receiver 4 may comprise a second elongated mating facility. The lower receiver 4 may comprise a trigger mechanism 6. The trigger mechanism 6 may be connected to the lower receiver 4 through employment of a trigger pin 56. The lower receiver 4 may comprise at least one safety selector 40. The lower receiver 4 may comprise a grip 46.

[0040] FIG. 8 illustrates an example lower receiver 4 fully mated to an example upper receiver 2 of an example firearm 800 according to various aspects of an embodiment. The upper receiver 2 may comprise a hammer 8. The hammer 8 may be pivotally connected to the upper receiver 2 through employment of a hammer pin 58. The upper receiver 2 may comprise a hammer spring. The hammer spring may comprise a first hammer portion 32. The hammer spring may have an inactive condition in which the first hammer portion 32 is connected to the hammer 8. The hammer spring may have an inactive condition in which the lower receiver 4 is connectable to the upper receiver 2. The hammer spring may have an inactive condition in which the lower receiver 4 is removable from the upper receiver 2. The upper receiver 2 may comprise a takedown pin 44. The takedown pin 44 may be employed to secure the lower receiver 4 when fully connected to the upper receiver 2. The lower receiver 4 may comprise a trigger mechanism 6. The trigger mechanism 6 may be connected to the lower receiver 4 through employment of a trigger pin 56. The lower receiver 4 may comprise at least one safety selector 40. The lower receiver 4 may comprise a grip 46.

[0041] FIG. 9 illustrates an example lower receiver 4 fully secured to an example upper

receiver 2 of an example firearm 900 according to various aspects of an embodiment. The upper receiver 2 may comprise a hammer 8. The hammer 8 may be pivotally connected to the upper receiver 2 through employment of a hammer pin 58. The upper receiver 2 may comprise a hammer spring. The hammer spring may comprise a first hammer portion 32. The hammer spring may have an inactive condition in which the first hammer portion 32 is connected to the hammer 8. The hammer spring may have an inactive condition in which the lower receiver 4 is connectable to the upper receiver 2. The hammer spring may have an inactive condition in which the lower receiver 4 is removable from the upper receiver 2. The upper receiver 2 may comprise a takedown pin 44. The takedown pin 44 may be employed to secure the lower receiver 4 when fully connected to the upper receiver 2, as shown. The lower receiver 4 may comprise a trigger mechanism 6. The trigger mechanism 6 may be connected to the lower receiver 4 through employment of a trigger pin 56. The lower receiver 4 may comprise at least one safety selector 40. The lower receiver 4 may comprise a grip 46.

[0042] FIG. 10A illustrates a side view of an example lower receiver 4 removed from an example upper receiver 2 of an example firearm 1000 according to various aspects of an embodiment. The upper receiver 2 may comprise a first elongated mating facility 12. The first elongated mating facility 12 may comprise a forward stop at a forward end 22. The first elongated mating facility 12 may comprise a selected first profile extending to a rear free end 24. The upper receiver 2 may comprise a hammer 8. The hammer 8 may be pivotally connected to the upper receiver 2 through employment of a hammer pin 58. The upper receiver 2 may comprise a hammer spring 10. The upper receiver 2 may comprise a takedown pin 44. The takedown pin 44 may be employed to secure the lower receiver 4 when fully connected to the upper receiver 2.The lower receiver 4 may comprise a second elongated mating facility. The lower receiver 4 may comprise a trigger mechanism 6. The trigger mechanism 6 may be connected to the lower receiver 4 through employment of a trigger pin 56. The lower receiver 4 may comprise at least one safety selector 40. The lower receiver 4 may comprise a grip 46.

[0043] FIG. 10B illustrates a side view of an example lower receiver 4 partially mated to an example upper receiver 2 of an example firearm 1001 according to various aspects of an embodiment. The upper receiver 2 may comprise a first elongated mating facility 12. The first elongated mating facility 12 may comprise a forward stop at a forward end 22. The upper receiver 2 may comprise a hammer 8. The hammer 8 may be pivotally connected to the upper receiver 2 through employment of a hammer pin 58. The upper receiver 2 may comprise a hammer spring 10. The upper receiver 2 may comprise a takedown pin 44. The takedown pin 44 may be employed to secure the lower receiver 4 when fully connected to the upper receiver 2.The lower receiver 4 may comprise a second elongated mating facility. The lower receiver 4 may comprise a trigger mechanism 6. The trigger mechanism 6 may be connected to the lower receiver 4 through employment of a trigger pin 56. The lower receiver 4 may comprise at least one safety selector 40. The lower receiver 4 may comprise a grip 46. [0044] FIG. 11 illustrates a cross-sectional view of an example lower receiver 4 partially mated to an example upper receiver 2 of an example firearm 1100 according to various aspects of an embodiment. The upper receiver 2 may comprise a first elongated mating facility. The first elongated mating facility may comprise a forward stop at a forward end 22. The upper receiver 2 may comprise a hammer 8. The hammer 8 may be pivotally connected to the upper receiver 2 through employment of a hammer pin 58. The upper receiver 2 may comprise a hammer spring. The hammer spring may comprise opposed end portions 32. Each of the opposed end portions 32 may be adapted to contact the lower receiver 4 to bias the hammer 8. The opposed end portions 32 may be adapted to engage the hammer 8 to enable mating of the lower receiver 4 to the upper receiver 2, as shown. The opposed end portions 32 may be adapted to engage the hammer 8 to enable removal of the lower receiver 4 from the upper receiver 2, as shown. The upper receiver 2 may define a magazine well 30 forward of the lower receiver 4. The lower receiver 4 may comprise a second elongated mating facility. The second elongated mating facility may comprise a rear stop at a rear end 26. The lower receiver 4 may comprise a trigger mechanism 6. The trigger mechanism 6 may be connected to the lower receiver 4 through employment of a trigger pin 56. The lower receiver 4 may comprise a safety selector body 42. The lower receiver 4 may comprise a grip 46.

[0045] FIGs. 12A and 12B illustrate views of an example first elongated mating facility and an example second elongated mating facility of example firearms (1200 and 1201) according to various aspects of an embodiment. The first elongated mating facility and the second elongated mating facility may comprise elongated tabs 16 and channels 18. The elongated tabs 16 may also be referred to as elongated tongues. The channels 18 may also be referred to as grooves or slots. In these illustrations, the first elongated mating facility comprises the channels 18, and the second elongated mating facility comprises the elongated tabs 16. However, a person of ordinary skill in the art will understand that the first elongated mating facility could comprise the elongated tabs 16, and the second elongated mating facility could comprise the channels 18. The first elongated mating facility may comprise a forward stop at a forward end 22. The first elongated mating facility may comprise a selected first profile extending to a rear free end 24. The firearms (1200 and 1201) may comprise a takedown pin 44. The firearms (1200 and 1201) may comprise a trigger mechanism 6. The trigger mechanism 6 may be connected to a lower receiver through employment of a trigger pin 56. The firearms (1200 and 1201) may comprise at least one safety selector 40. [0046] According to an embodiment, a firearm may comprise a first elongated mating facility and a second elongated mating facility. The first elongated mating facility may define at least one channel (for example 18) facing laterally away from an upper receiver. The second elongated mating facility may comprise at least one elongated tab (for example 16). Each of the at least one elongated tab (for example 16) may be adapted to be closely and slideably received in one of the at least one channel (for example 18).

[0047] FIG. 13 illustrates a cross-sectional view of an example first elongated mating facility and an example second elongated mating facility of an example firearm 1300 according to an aspect of an embodiment. At least a first one of the first elongated mating facility and the second elongated mating facility may comprise at least one dovetail element 20. One of the first elongated mating facility and the second elongated mating facility may comprise opposed channels facing in opposed directions. The opposed channels may be formed as part of two dovetail elements 20. The other of the first elongated mating facility and the second elongated mating facility may comprise opposed tabs 16 facing in opposed directions and adapted to be slideably received in the opposed channels. The firearm 1300 may comprise a hammer 8. The firearm 1300 may comprise a hammer spring in contact with the hammer 8. The hammer spring may comprise opposed end portions 32. The firearm 1300 may comprise a takedown pin 44. The firearm 1300 may comprise at least one safety selector 40. The firearm 1300 may comprise a safety selector body 42.

[0048] According to an embodiment, a firearm may comprise a first elongated mating facility and a second elongated mating facility. One of the first elongated mating facility and the second elongated mating facility may comprise a first pair of opposed tabs (for example 20) extending toward each other. The other of the first elongated mating facility and the second elongated mating facility may comprise a second pair of opposed tabs (for example 16) extending away from each other and adapted to engage the first pair.

[0049] FIGs. 14A and 14B illustrate top cutaway views of an example first elongated mating facility and an example second elongated mating facility of example firearms (1400 and 1401) according to various aspects of an embodiment. The first elongated mating facility may comprise at least one first protrusion 48. The at least one first protrusion 48 may be adapted to engage the second elongated mating facility. The second elongated mating facility may comprise at least one second protrusion 49. The at least one second protrusion 49 may be adapted to engage the first elongated mating facility. The firearms (1400 and 1401) may comprise a hammer 8. The hammer 8 may be pivotally connected to the firearms (1400 and 1401) through employment of a hammer pin 58. The firearms (1400 and 1401) may comprise at least one safety selector 40. The firearms (1400 and 1401) may comprise a safety selector body 42.

[0050] FIG. 15A illustrates an example lower receiver 1500 according to various aspects of an embodiment. The lower receiver 1500 may comprise a lower receiver frame 4. The lower receiver frame 4 may comprise a second elongated mating facility 14. The second elongated mating facility 14 may comprise a rear stop at a rear end 26. The second elongated mating facility 14 may comprise a selected second profile extending to a forward free end 28, such that the lower receiver frame 4 may be connected to an upper receiver frame (for example 2) from the rear end and slid forward to a stop position. The lower receiver 1500 may comprise a trigger mechanism 6. The trigger mechanism 6 may be connected to the lower receiver frame 4 through employment of a trigger pin 56. The lower receiver 1500 may comprise at least one safety selector 40. The lower receiver 1500 may comprise at least one safety selector body 42. The lower receiver 1500 may comprise a grip 46.

[0051] FIG. 15B illustrates an exploded view of an example lower receiver 1501 according to various aspects of an embodiment. The lower receiver 1501 may comprise a lower receiver frame 4. The lower receiver frame 4 may comprise a second elongated mating facility 14. The second elongated mating facility 14 may comprise a rear stop at a rear end 26. The second elongated mating facility 14 may comprise a selected second profile extending to a forward free end 28, such that the lower receiver frame 4 may be connected to an upper receiver frame (for example 2) from the rear end and slid forward to a stop position. The lower receiver 1501 may comprise a trigger mechanism 6. The trigger mechanism 6 may be connected to the lower receiver frame 4 through employment of a trigger pin. The trigger pin may comprise a threaded trigger pin 56A. The threaded trigger pin 56A may be adapted to receive trigger pin screw 56B. The trigger pin may comprise at least one disconnector bushing 56C. The lower receiver 1501 may comprise a safety selector assembly. The safety selector assembly may comprise at least one safety selector 40A. The safety selector assembly may comprise a safety selector body 42. The safety selector body 42 may be adapted to receive the at least one safety selector 40A. The at least one safety selector 40A may be secured to the safety selector body 42 through employment of at least one safety selector screw 40B. The lower receiver 1501 may comprise a safety selector detent 52 A. The safety selector detent 52A may be adapted to engage the safety selector body 42. The safety selector detent 52A may be engaged with the safety selector body 42 through employment of a safety selector detent spring 52B. The safety selector detent 52A and the safety selector detent spring 52B may be retained in the lower receiver frame 4 through employment of safety selector detent screw 52C. The lower receiver 1501 may comprise a grip 46.

[0052] FIG. 16A illustrates an example elongated top cover 60 of example firearm 1600

according to an aspect of various embodiments. The firearm 1600 may comprise a frame 2. The firearm 1600 may comprise the elongated top cover 60. The elongated top cover 60 may comprise a forward end pivotally connected to the frame 2. The forward end may be pivotally connected to the frame 2 through employment of a pivot pin 64. The elongated top cover 60 may comprise at least one pivot detent 66. The elongated top cover 60 may comprise a rear end opposed to the forward end. The firearm 1600 may comprise an actuator 62. The actuator 62 may be connected to the elongated top cover 60. The actuator 62 may have a rear portion with an exposed actuation surface 70. The elongated top cover 60 may be movable between an open position and a closed position, as shown. In the closed position, the rear end may be adjacent the frame 2. The elongated top cover 60 may comprise an integrated accessory rail.

[0053] FIG. 16B illustrates an example elongated top cover 60 of example firearm 1601

according to an aspect of various embodiments. The firearm 1601 may comprise a frame 2. The firearm 1601 may comprise the elongated top cover 60. The elongated top cover 60 may comprise a forward end pivotally connected to the frame 2. The forward end may be pivotally connected to the frame 2 through employment of a pivot pin 64. The elongated top cover 60 may comprise at least one pivot detent 66. The elongated top cover 60 may comprise a rear end opposed to the forward end. The firearm 1601 may comprise an actuator 62. The actuator 62 may be connected to the elongated top cover 60. The actuator 62 may have a rear portion with an exposed actuation surface 70. The elongated top cover 60 may be movable between an open position, as shown, and a closed position. In the open position, the rear end may be away from the frame 2. The at least one pivot detent 66 may be employed to support the elongated top cover 60 in the open position. The firearm 1601 may comprise a latch 80. The latch 80 may be connected to the frame 2. The latch 80 may be operable to reciprocate between a forward released position and a rearward latched position. The latch 80 may be spring biased to the rearward latched position. The latch 80 may be spring biased through employment of a recoil spring 90. The latch 80 may comprise a cam surface 82. The cam surface 82 may be operable to move the latch 80 in the forward direction in response to movement of the elongated top cover 60 toward the closed position.

[0054] FIG. 17 illustrates a side view of an example elongated top cover 60 of an example firearm 1700 according to various aspects of an embodiment. The firearm 1700 may comprise a frame 2. The firearm 1700 may comprise the elongated top cover 60. The elongated top cover 60 may comprise a forward end pivotally connected to the frame 2. The forward end may be pivotally connected to the frame 2 through employment of a pivot pin 64. The elongated top cover 60 may comprise at least one pivot detent 66. The firearm 1700 may comprise an actuator 62. The actuator 62 may be connected to the elongated top cover 60. The elongated top cover 60 may be movable between an open position and a closed position, as shown.

[0055] FIG. 18 illustrates an example latch 80 installed on an example firearm 1800 according to various aspects of an embodiment. The firearm 1800 may comprise a frame 2. The firearm 1800 may comprise the latch 80. The latch 80 may be connected to the frame 2. The latch 80 may be operable to reciprocate between a forward released position and a rearward latched position. The latch 80 may be spring biased to the rearward latched position. The latch 80 may be spring biased through employment of a recoil spring 90.

[0056] FIG. 19 illustrates an example elongated top cover 1900 according to an aspect of an embodiment. The elongated top cover 1900 may comprise an elongated top cover body 60. The elongated top cover 1900 may comprise a pivot pin 64. The elongated top cover 1900 may comprise an actuator 62. The actuator 62 may comprise a latch actuation surface 72. The elongated top cover 1900 may comprise a forward end adapted to pivotally connect to a frame of a firearm. The elongated top cover 1900 may comprise a latch engagement facility 68 at a rear end, the rear end opposed to the forward end.

[0057] FIG. 20A illustrates a cross-sectional view of an example elongated top cover 60 that is fully latched to an example frame 2 of an example firearm 2000 according to various aspects of an embodiment. The elongated top cover 60 may comprise an actuator 62. The actuator 62 may define an actuator axis. The actuator 62 may be operable to reciprocate between a rest position, as shown, and a pressed position with respect to the elongated top cover 60. The actuator 62 may be spring biased to the rest position through employment of an actuator spring 62C. The actuator 62 may have a rear portion with an exposed actuation surface 70. The actuator 62 may have a forward portion having a latch actuation surface 72. The latch actuation surface 72 may be angled with respect to the actuator axis. The latch actuation surface 72 may face in a direction that is forward and downward. The latch actuation surface 72 may be adjacent a latch 80 when the elongated top cover 60 is in the closed position, as shown. The latch 80 may be connected to the frame 2. The latch 80 may be operable to reciprocate between a forward released position and a rearward latched position, as shown. The latch 80 may be spring biased to the rearward latched position. The latch 80 may be spring biased through employment of a recoil spring 90. The latch 80 may comprise a cam surface 82. The cam surface 82 may be operable to move the latch 80 in the forward direction in response to movement of the elongated top cover 60 toward the closed position.

[0058] FIG. 20B illustrates a cross-sectional view of an example elongated top cover 60 with a partially depressed actuator 62 of an example firearm 2001 according to various aspects of an embodiment. The elongated top cover 60 may comprise the actuator 62. The actuator 62 may be operable to reciprocate between a rest position and a pressed position with respect to the elongated top cover 60. The actuator 62 may be spring biased to the rest position through employment of an actuator spring 62C. The actuator 62 may have a rear portion with an exposed actuation surface 70. The actuator 62 may have a forward portion having a latch actuation surface 72. The latch actuation surface 72 may be adjacent a latch 80 when the elongated top cover 60 is in the closed position, as shown. The latch 80 may be connected to the frame 2. The latch 80 may be operable to reciprocate between a forward released position and a rearward latched position. The latch 80 may be partially

reciprocated, as shown, between the forward released position and the rearward latched position when the actuator 62 is partially depressed, as shown. The latch 80 may be spring biased to the rearward latched position. The latch 80 may be spring biased through employment of a recoil spring 90. The latch 80 may comprise a cam surface 82. The cam surface 82 may be operable to move the latch 80 in the forward direction in response to movement of the elongated top cover 60 toward the closed position.

[0059] FIG. 21 illustrates a cross-sectional view of an example elongated top cover 60 that is unlatched from an example frame 2 of an example firearm 2100 according to an aspect of an embodiment. The elongated top cover 60 may comprise an actuator 62. The actuator 62 may be operable to reciprocate between a rest position and a pressed position, as shown, with respect to the elongated top cover 60. The actuator 62 may be spring biased to the rest position through employment of an actuator spring 62C. The actuator 62 may have a rear portion with an exposed actuation surface 70. The actuator 62 may have a forward portion having a latch actuation surface 72. The latch actuation surface 72 may be adjacent a latch 80 when the elongated top cover 60 is in the closed position, as shown. The latch 80 may be connected to the frame 2. The latch 80 may be operable to reciprocate between a forward released position, as shown, and a rearward latched position. The latch 80 may be spring biased to the rearward latched position. The latch 80 may be spring biased through employment of a recoil spring 90. The elongated top cover 60 may comprise a latch engagement facility. The latch engagement facility may comprise an engagement surface 78. The engagement surface 78 may be adapted to contact a ledge surface 84 of the latch 80 when the elongated top cover 60 is in the closed position and the actuator 62 is in the rest position.

[0060] FIG. 22 illustrates a cross-sectional view of an example elongated top cover 60 in a partially open position on an example firearm 2200 according to an aspect of an embodiment. The elongated top cover 60 may comprise an actuator 62. The actuator 62 may be operable to reciprocate between a rest position, as shown, and a pressed position with respect to the elongated top cover 60. The actuator 62 may be spring biased to the rest position through employment of an actuator spring 62C. The actuator 62 may have a rear portion with an exposed actuation surface 70. The actuator 62 may have a forward portion having a latch actuation surface 72. The latch actuation surface 72 may be adjacent a latch 80 when the elongated top cover 60 is in the closed position. The latch 80 may be connected to the frame 2. The latch 80 may be operable to reciprocate between a forward released position and a rearward latched position. The latch 80 may be spring biased to the rearward latched position. The latch 80 may be spring biased through employment of a recoil spring 90. The latch 80 may comprise a cam surface 82. The cam surface 82 may be operable to move the latch 80 in the forward direction in response to movement of the elongated top cover 60 toward the closed position. The elongated top cover 60 may comprise a latch engagement facility. The latch engagement facility may comprise an engagement surface 78. The engagement surface 78 may be adapted to contact a ledge surface 84 of the latch 80 when the elongated top cover 60 is in the closed position and the actuator 62 is in the rest position.

[0061] FIG. 23 illustrates a cross-sectional view of an example elongated top cover 60

engaged with an example latch 80 of an example firearm 2300 during closing of the elongated top cover 60 according to an aspect of an embodiment. The elongated top cover 60 may comprise an actuator 62. The actuator 62 may be operable to reciprocate between a rest position and a pressed position with respect to the elongated top cover 60. The actuator 62 may be spring biased to the rest position through employment of an actuator spring 62C. The actuator 62 may have a rear portion with an exposed actuation surface 70. The actuator 62 may have a forward portion having a latch actuation surface 72. The latch actuation surface 72 may be adjacent the latch 80 when the elongated top cover 60 is in the closed position. The latch 80 may be connected to a frame 2. The latch 80 may be operable to reciprocate between a forward released position and a rearward latched position. The latch 80 may be spring biased to the rearward latched position. The latch 80 may be spring biased through employment of a recoil spring 90. The elongated top cover 60 may comprise a latch engagement facility. The latch engagement facility may comprise an engagement surface 78. The latch 80 may comprise a cam surface 82. The cam surface 82 may be operable to move the latch 80 in the forward direction in response to movement of the elongated top cover 60 toward the closed position.

[0062] FIG. 24 illustrates an exploded view of an example elongated top cover 2400 according to an aspect of an embodiment. The elongated top cover 2400 may comprise an elongated top cover body 60. The elongated top cover 2400 may comprise an actuator. The actuator may comprise an elongated actuator body 62A defining an actuator axis. The actuator may define an elongated bore receiving an actuator spring 62C. The actuator 62 may have a rear portion with an exposed actuation surface 70. The elongated bore may be open at a forward end. The actuator spring 62C may comprise a coil spring. The actuator may define a slot 62D. The elongated top cover 2400 may comprise a limit pin 62B received in the slot 62D. The elongated top cover 2400 may define an aperture 74. The actuator may be received in the aperture 74. The elongated top cover 2400 may comprise a latch engagement facility. The latch engagement facility may comprise an engagement block 68A. The engagement block 68A may comprise an engagement surface 78. The engagement block 68A may be connected to the elongated top cover body 60 through employment of engagement block screws 68B. The elongated top cover 2400 may be adapted to pivotally connect to a frame of a firearm. The elongated top cover 2400 may be adapted to pivotally connect to the frame through employment of a pivot pin. The pivot pin may comprise a pivot pin body 64A. The elongated top cover body 60 may comprise at least one bore adapted to receive the pivot pin body 64 A. The pivot pin body 64A may be secured in the top cover body 60 through employment of a pivot pin screws 64B. The elongated top cover 2400 may comprise at least one pivot detent. Each of the at least one pivot detent may comprise a detent 66C. The elongated top cover body 60 may comprise at least one bore adapted to receive at least one detent 66C. The at least one detent 66C may be activated by at least one detect spring 66B. The at least one detent 66C may be secured to the elongated top cover body 60 through employment of at least one detent screw 66A.

[0063] There is thus provided, in accordance with an embodiment of the present disclosure, a firearm. The firearm may comprise an upper receiver. The upper receiver may define a passage adapted to receive a reciprocating bolt. The passage may define a primary axis. The firearm may comprise a lower receiver removably connected to the upper receiver. The lower receiver may comprise a trigger mechanism. The firearm may comprise a hammer pivotally connected to the upper receiver and movable between a retracted position and a forward position. The firearm may comprise a hammer spring operably interconnecting the lower receiver and the hammer. The hammer spring may be adapted to bias the hammer toward the forward position. The upper receiver may comprise a first elongated mating facility parallel to the primary axis. The lower receiver may comprise a second elongated mating facility parallel to the primary axis. The second elongated mating facility may be adapted to mate with the first elongated mating facility. The second elongated mating facility may be adapted to mate with the first elongated mating facility to prevent relative displacement and motion between the upper receiver and the lower receiver except in a direction parallel to the primary axis.

[0064] According to an embodiment, a first elongated mating facility and a second elongated mating facility may comprise elongated tabs and channels.

[0065] According to an embodiment, at least a first one of a first elongated mating facility and a second elongated mating facility may comprise a dovetail element.

[0066] According to an embodiment, a first elongated mating facility may define a channel facing laterally away from an upper receiver.

[0067] According to an embodiment, a second elongated mating facility may comprise an elongated tab adapted to be closely and slideably received in a channel.

[0068] According to an embodiment, one of a first elongated mating facility and a second elongated mating facility may comprise opposed channels facing in opposed directions. The other of the first elongated mating facility and the second elongated mating facility may comprise opposed tabs facing in opposed directions. The opposed tabs may be adapted to be slideably received in the opposed channels.

[0069] According to an embodiment, one of a first elongated mating facility and a second elongated mating facility may comprise a first pair of opposed tabs extending toward each other. The other of the first elongated mating facility and the second elongated mating facility may include a second pair of opposed tabs extending away from each other. The second pair of opposed tabs may be adapted to engage the first pair.

[0070] According to an embodiment, a first elongated mating facility may comprise a forward stop at a forward end. The first elongated mating facility may comprise a selected first profile extending to a rear free end. A second elongated mating facility may comprise a rear stop at a rear end. The second elongated mating facility may comprise a selected second profile extending to a forward free end, such that a lower receiver may be connected to an upper receiver from the rear end and slid forward to a stop position.

[0071] According to an embodiment, an upper receiver may define a magazine well forward of a lower receiver.

[0072] According to an embodiment, a hammer spring may have an active position in which a first hammer portion of the hammer spring is connected to a lower receiver and a second hammer portion of the hammer spring is connected to a hammer to bias the hammer toward a forward position. The hammer spring may have an inactive condition in which the first hammer portion is connected to the hammer and the lower receiver is removable from the upper receiver.

[0073] According to an embodiment, a hammer spring may comprise an intermediate portion contacting a hammer. The hammer spring may comprise opposed end portions. Each of the opposed end portions may be adapted to contact a lower receiver to bias the hammer. The opposed end portions may be adapted to engage the hammer to enable removal of the lower receiver from an upper receiver.

[0074] There is thus provided, in accordance with an embodiment of the present disclosure, a firearm. The firearm may comprise a frame. The firearm may comprise an elongated top cover. The elongated top cover may comprise a forward end pivotally connected to the frame. The elongated top cover may comprise a latch engagement facility at a rear end. The rear end may be opposed to the forward end. The firearm may comprise a latch connected to the frame. The latch may be operable to reciprocate between a forward released position and a rearward latched position. The latch may be spring biased to the rearward latched position. The elongated top cover may be movable between an open position in which the rear end is away from the frame, and a closed position in which the rear end is adjacent the frame. The latch may comprise a cam surface. The cam surface may be operable to move the latch in the forward direction in response to movement of the elongated top cover toward the closed position. The latch engagement facility may comprise an engagement surface. The engagement surface may be adapted to contact a ledge surface of the latch when the elongated top cover is in the closed position. The firearm may comprise an actuator. The actuator may be connected to the elongated top cover. The actuator may be operable to reciprocate between a rest position and a pressed position with respect to the elongated top cover. The actuator may comprise a rear portion with an exposed actuation surface. The actuator may comprise a forward portion having a latch actuation surface adjacent the latch when the elongated top cover is in the closed position.

[0075] According to an embodiment, an elongated top cover may define an aperture. An actuator may be received in the aperture.

[0076] According to an embodiment, an actuator may be spring biased to a rest position.

[0077] According to an embodiment, an actuator may be an elongated actuator body defining an actuator axis.

[0078] According to an embodiment, a latch actuation surface may be angled with respect to an actuator axis. [0079] According to an embodiment, a latch actuation surface may face in a direction forward and downward.

[0080] According to an embodiment, an actuator may define a slot. An elongated top cover may include a limit pin received in the slot.

[0081] According to an embodiment, an actuator may define an elongated bore receiving an actuator spring.

[0082] According to an embodiment, an elongated bore may be open at a forward end. An actuator spring may be a coil spring.

[0083] Various embodiments have been presented. Each of these embodiments may of course include features from other embodiments presented, and embodiments not specifically described may include various features described herein.

[0084] A person of ordinary skill in the art will appreciate that components shown in and described with respect to the figures are provided by way of example only. Numerous other configurations are possible. Accordingly, embodiments of the present disclosure should not be construed as being limited to any particular configuration. It will be appreciated that while the disclosure may in certain instances describe a single example embodiment, there may be other configurations, shapes, and orientations of facilities and components without departing from example embodiments of the present disclosure. A person of ordinary skill in the art will recognize the applicability of embodiments of the present disclosure to various firearms, firearm platforms, firearm components, firearm accessories, and combinations thereof known in the art. A person of ordinary skill in the art may recognize that embodiments of the present disclosure may comprise forged, milled, printed, combinations thereof, and/or the like parts comprising one material or a plurality of materials. A person of ordinary skill in the art will appreciate that components and elements shown in and described with respect to FIGS. 1-24 are provided by way of example only. Numerous other firearms, receivers, top covers, trigger mechanisms, bolts, recoil springs, grips, and various firearm component configurations are possible. Accordingly, embodiments of the present disclosure should not be construed as being limited to any particular firearm, firearm platform, or firearm component. Additionally, it is to be recognized that, while the present disclosure has been described above in terms of one or more embodiments, it is not limited thereto. Various features, aspects, and/or components of the above described present disclosure may be used individually or jointly. Accordingly, the claims set forth below should be construed in view of the full breadth of the embodiments as disclosed herein. [0085] In this specification, "a" and "an" and similar phrases are to be interpreted as "at least one" and "one or more." References to "a", "an", and "one" are not to be interpreted as "only one". References to "an" embodiment in this disclosure are not necessarily to the same embodiment.

[0086] Furthermore, many features presented above are described as being optional through the use of "may" or the use of parentheses. For the sake of brevity and legibility, the present disclosure does not explicitly recite each and every permutation that may be obtained by choosing from the set of optional features. However, the present disclosure is to be interpreted as explicitly disclosing all such permutations. For example, a system described as having three optional features may be embodied in seven different ways, namely with just one of the three possible features, with any two of the three possible features or with all three of the three possible features.

[0087] Further, the purpose of the Abstract of the Disclosure is to enable the Patent Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The Abstract of the Disclosure is not intended to be limiting as to the scope in any way.

[0088] Finally, it is the applicant's intent that only claims that include the express language "means for" or "step for" be interpreted under 35 U.S.C. 112. Claims that do not expressly include the phrase "means for" or "step for" are not to be interpreted under 35 U.S.C. 112.

Claims

CLAIMS: I claim:

1. A firearm comprising:

an upper receiver defining a passage adapted to receive a reciprocating bolt; the passage defining a primary axis;

a lower receiver removably connected to the upper receiver;

the lower receiver including a trigger mechanism;

a hammer pivotally connected to the upper receiver and movable between a retracted position and a forward position;

a hammer spring operably interconnecting the lower receiver and the hammer and adapted to bias the hammer toward the forward position;

the upper receiver having a first elongated mating facility parallel to the primary axis; the lower receiver having a second elongated mating facility parallel to the primary axis and adapted to mate with the first elongated mating facility to prevent relative displacement and motion between the upper receiver and the lower receiver except in a direction parallel to the primary axis.

2. The firearm according to claim 1 wherein the first elongated mating facility and the second elongated mating facility include elongated tabs and channels.

3. The firearm according to claim 1 or 2 wherein at least a first one of the first elongated mating facility and the second elongated mating facility includes a dovetail element.

4. The firearm according to any one of claims 1 to 3 wherein the first elongated mating facility defines a channel facing laterally away from the upper receiver.

5. The firearm according to claim 4 wherein the second elongated mating facility includes an elongated tab adapted to be closely and slideably received in the channel.

6. The firearm according to any one of claims 1 to 5 wherein one of the first elongated mating facility and the second elongated mating facility includes opposed channels facing in opposed directions, and the other of the first elongated mating facility and the second elongated mating facility includes opposed tabs facing in opposed directions and adapted to be slideably received in the opposed channels.

7. The firearm according to any one of claims 1 to 6 wherein one of the first elongated mating facility and the second elongated mating facility includes a first pair of opposed tabs extending toward each other, and the other of the first elongated mating facility and the second elongated mating facility includes a second pair of opposed tabs extending away from each other and adapted to engage the first pair.

8. The firearm according to any one of claims 1 to 7 wherein the first elongated mating facility includes a forward stop at a forward end, and a selected first profile extending to a rear free end, and the second elongated mating facility includes a rear stop at a rear end and a selected second profile extending to a forward free end, such that the lower receiver may be connected to the upper receiver from the rear end and slid forward to a stop position.

9. The firearm according to any one of claims 1 to 8 wherein the upper receiver defines a magazine well forward of the lower receiver.

10. The firearm according to any one of claims 1 to 9 wherein the hammer spring has an active position in which a first hammer portion of the hammer spring is connected to the lower receiver and a second hammer portion of the hammer spring is connected to the hammer to bias the hammer toward the forward position, the hammer spring having an inactive condition in which the first hammer portion is connected to the hammer and the lower receiver is removable from the upper receiver.

11. The firearm according to any one of claims 1 to 10 wherein the hammer spring has an intermediate portion contacting the hammer, and opposed end portions each adapted to contact the lower receiver to bias the hammer, the opposed end portions adapted to engage the hammer to enable removal of the lower receiver from the upper receiver.

12. A firearm comprising:

a frame;

an elongated top cover having a forward end pivotally connected to the frame;

the elongated top cover having a latch engagement facility at a rear end, the rear end opposed to the forward end;

a latch connected to the frame and operable to reciprocate between a forward released position and a rearward latched position;

the latch being spring biased to the rearward latched position;

the elongated top cover movable between an open position in which the rear end is away from the frame and a closed position in which the rear end is adjacent the frame;

the latch having a cam surface operable to move the latch in the forward direction in response to movement of the elongated top cover toward the closed position;

the latch engagement facility having an engagement surface adapted to contact a ledge surface of the latch when the elongated top cover is in the closed position;

an actuator connected to the elongated top cover and operable to reciprocate between a rest position and a pressed position with respect to the elongated top cover; and the actuator having a rear portion with an exposed actuation surface and a forward portion having a latch actuation surface adjacent the latch when the elongated top cover is in the closed position.

13. The firearm according to claim 12 wherein the elongated top cover defines an aperture and the actuator is received in the aperture.

14. The firearm according to claim 12 or 13 wherein the actuator is spring biased to the rest position.

15. The firearm according to any one of claims 12 to 14 wherein the actuator is an elongated actuator body defining an actuator axis.

16. The firearm according to claim 15 wherein the latch actuation surface is angled with respect to the actuator axis.

17. The firearm according to any one of claims 12 to 16 wherein the latch actuation surface faces in a direction forward and downward.

18. The firearm according to any one of claims 12 to 17 wherein the actuator defines a slot, and wherein the elongated top cover includes a limit pin received in the slot.

19. The firearm according to any one of claims 12 to 18 wherein the actuator defines an elongated bore receiving an actuator spring.

20. The firearm according to claim 19 wherein the elongated bore is open at a forward end and wherein the actuator spring is a coil spring.