Patent Application
20120313301
1. Field of the Invention
Embodiments of the invention generally relate to a method and apparatus for annealing metallic objects. More specifically, embodiments described herein relate to a method and apparatus for annealing elongated, tubular cases made of a metallic material, such as brass ammunition cartridges, or ammunition cases or casings.
2. Description of the Related Art
Annealing is a process where heat is applied to a metal in order to change the properties, such as strength and hardness, of the metal. Annealing is typically utilized to improve ductility, relieve internal stresses, and generally soften metals that have been hardened by working the metal and/or heat treatment. Proper annealing restores the properties of the metal to a near original or virgin state.
Ammunition cartridges or cases are made from brass which is subject to hardening during manufacture, use, and reloading of the cases. Commercially available cartridges are typically annealed during manufacture to include various hardnesses along the length of the case. For example, firearm cartridges typically include a base at a first end thereof where the primer is located and a mouth at a second end thereof where the projectile is held. In a properly annealed cartridge the mouth will have a greater ductility than the base. However, when the cartridge is used to discharge a projectile, heat is created which causes the case to expand and contract, thus hardening the case, and particularly, the mouth of the case. Reuse (i.e., reloading) of the case requires subsequent processing, such as sizing and trimming of the case, which may work-harden portions of the case. If the hardened portions of the case are not annealed, such as the mouth (or neck, in shouldered cases), the mouth may crack and render the cartridge unusable. Thus, annealing of the cases assures proper operation of the cartridge as well as extends the lifetime of the case for subsequent reuse.
Devices for annealing ammunition cases are commercially available; however, the commercially available devices suffer from some drawbacks. In one commercially available device, only a single case may be loaded and annealed at one time, which is time consuming and labor intensive. Other conventional devices typically hold multiple cases vertically in a turntable that rotates in a horizontal plane. The commercial devices do not include an automatic case loading device. Loading of the turntable is thus done manually to assure that the case is properly oriented in the turntable (e.g., mouth up/base down). This requires constant supervision by personnel during operation to ensure efficient throughput. Further, the horizontally oriented turntable devices are heavy and occupy a large footprint. Additionally, the conventional devices often require more than one heat source, which increases the cost of the annealing operation. While these conventional devices may be suitable for the occasional user, the devices are not desirable for commercial operations and/or frequent users.
Thus, there exists a need in the art for a method and apparatus for an annealing device capable of automatic loading of cases, high-throughput and requires a smaller footprint.
Embodiments described herein relate to a method and apparatus for annealing elongated, tubular casings made of a metallic material, such as brass ammunition cases. In one embodiment, a case annealing apparatus is provided. The case annealing apparatus includes a base, a feeding device having a first end tapering to a second end that is coupled to the base, a rotatable feed wheel assembly disposed adjacent a second end of the feeding device, a linear slide mechanism disposed adjacent the rotatable feed wheel assembly defining a portion of a case receiving region, and a heating device disposed adjacent the case receiving region, the heating device operable to heat a portion of a case retained in the case receiving region.
A case annealing apparatus is provided in another embodiment. The case annealing apparatus includes a base, a motor coupled to the base, a feed wheel assembly coupled by a shaft to the motor, a slide mechanism disposed adjacent the feed wheel assembly, the slide mechanism movable in a linear direction that is controlled by the motor, and a heating device coupled to the base and oriented to direct thermal energy to a case receiving region contained between the feed wheel assembly and the slide mechanism.
A case annealing apparatus is provided in another embodiment. The case annealing apparatus includes a body comprising a front panel and two opposing walls, the front panel oriented in an acute angle relative to a horizontal plane, a feeding device coupled to and coplanar with the front panel, a rotatable feed wheel assembly disposed adjacent an end of the feeding device, a linear slide mechanism disposed adjacent the rotatable feed wheel assembly defining a portion of a case receiving region, and a heating device disposed adjacent the case receiving region, wherein rotation of the rotatable feed wheel assembly and movement of the linear slide mechanism are controlled by a common motor.
So that the manner in which the above-recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation.
Embodiments described herein relate to a method and apparatus for annealing elongated, tubular casings made of a metallic material. The casings or cases as described herein include cylindrical ammunition cartridges, but may also include other workpieces, such as pieces of small diameter pipe and polygonal tubing. Various embodiments described herein may be described in relation to independent directions and/or in horizontal and vertical planes. Vertical is defined as orthogonal to a horizontal direction or plane and will be referred to as the Z direction. Horizontal is defined as orthogonal to a vertical direction or plane and will be referred to as the X or Y direction, the X direction being orthogonal to the Y direction, and vice-versa. The X, Y, and Z directions will be further defined with directional insets included as needed in the Figures to aid the reader.
The case annealing apparatus 100 also comprises a roller plate 120 adjacent a first guide rail 122A and a second guide rail 122B. In one embodiment, the roller plate 120 comprises a linear slide plate that is coupled to support member 124. The upper surface of the roller plate 120, the first guide rail 122A, and the second guide rail 122B form a case receiving region 125. The support member 124 extends through a slot 126 formed in the front panel 104. The support member 124 is in selective communication with a geared timing wheel (shown in
The case annealing apparatus 100 also comprises a heat source 128 adjacent the roller plate 120. The heat source 128 may comprise a heating device adapted to emit thermal energy and transfer heat by conduction, convection, or radiation. The heat source 128 may provide thermal energy by combustion, electricity, or optically. In the embodiment shown in
In operation, the feed wheel assembly 118 receives a case (not shown) from the feeding device 110. The feed wheel assembly 118 is rotated to transfer the case to the case receiving region 125 where the case is supported by the roller plate 120. In this position, a portion of the case extends out of the case receiving region 125 and is in proximity to the heat source 128. The heat source 128 may be activated to provide thermal energy to the case. As the case is heated, the case is rotated in a single axis within the case receiving region 125 to allow the thermal energy from the heat source 128 to impinge and treat, e.g., anneal, the entire circumference of the case.
The case annealing apparatus 100 also includes a motor 144 which facilitates movement of the roller plate 120 and the feed wheel assembly 118 (both shown in
The case 200′ is subjected to heat treatment in the case receiving region 125 by thermal energy provided by the nozzle 132. The case 200′ includes a first end 210A and a second end 210B. Specifically, heat applied from the nozzle 132 is directed to the first end 210A of the case 200′ when the case 200′ is in the case receiving region 125. When the case 200′ is in the case receiving region 125, the roller plate 120 is actuated to move linearly by the geared timing wheel 146. As the case 200′ is in contact with the roller plate 120, the movement of the roller plate 120 causes the case 200′ to rotate on axis A. The case 200′ is restrained from moving laterally by the guide rails 122A and 122B. The rotation of the case 200′ in axis A is clockwise when the roller plate 120 is moved in direction DA. While the case 200′ is rotated in axis A and is subject to heat treatment, the feed wheel assembly 118 continues to rotate and receive cases 200 from the feeding device 110. For example, case 200″ is received in channel 205B and rotated clockwise to the case receiving region 125.
In one embodiment, the body 102 of the case annealing apparatus 100 comprises a base 212 disposed in a first plane 215. The first plane 215 may be a horizontal plane. The roller plate 120 includes a support surface 220 adapted to contact a case 200. The support surface 220 of the roller plate 120 is disposed in a second plane 225 that is different than the first plane 215 of the base 212. For example, the first plane 215 may be offset from the second plane 225 by an angle α. The angle α may be about 10 degrees to about 45 degrees, such as about 15 degrees to about 30 degrees. The offset of the planes 215, 225 causes the case 200 to be supported by the second guide rail 122B and the support surface 220 of the roller plate 120. The first guide rail 122A provides axial stabilization of the case 200 in the case receiving region 125 during movement of the roller plate 120.
Rotation of the shaft 302 by the motor 144 rotates the geared timing wheel 146 in a counterclockwise direction in one embodiment. The geared timing wheel 146 includes one or more teeth 305A-305D that engage with the support member 124, which supports the roller plate 120 on the opposing side of the front panel 104. The support member 124 includes a raised contact plate 310 that is contacted by the teeth 305. As the geared timing wheel 146 is rotated counterclockwise (which coincides with the rotation of the feed wheel assembly 118 (shown in FIGS. 2A and 2B)), a surface 315 of tooth 305A contacts the raised contact plate 310 and pushes the support member 124 in direction DA relative to a linear support track 316. As the roller plate 120 is coupled to the support member 124, the movement of the support member 124 in the direction DA results in identical motion of the roller plate 120, as shown in
The support plates 500 are coupled to the shaft 302 in a manner that coaxially aligns the slots 510 to define channels that stably support a case 200. Specifically, each slot 510 is sized to receive a diameter of a body 515 of the case 200. The number of support plates 500 may be based on the length of the case 200 to be processed and/or the thickness of the individual support plates 500. The support plates 500 should be sufficient in number, sized and/or spaced to support about two-thirds of the length of the case 200 thereby leaving about one-third of the case 200 unsupported to facilitate heating of the unsupported one-third of the case 200. Thus, the support plates 500 may be two or more thin plates having spacers 520 therebetween. In the embodiment shown, three support plates 500 and two spacers 520 are shown for use with longer length cases, such as casings for .50 caliber cartridges (e.g., cartridges with projectiles having a diameter of about 0.5 inches), such as .50 Browning Machine Gun (BMG) cartridges. However, two support plates 500 and one spacer 520 may be used for smaller cases, such as casings for .223 caliber cartridges (e.g., cartridges with projectiles having a diameter of about 0.2 inches). The feed wheel assembly 118 may be easily coupled to and decoupled from the shaft 302 to facilitate replacement of support plates 500 for casings utilized for different caliber cartridges.
Embodiments of the case annealing apparatus 100 as described herein provide an annealing device adapted for higher throughput with minimal operational monitoring by personnel. Additionally, the case annealing apparatus 100 occupies a smaller footprint. The case annealing apparatus 100 as described herein provides a feeding device 110 that holds a plurality of cases and feeds single cases to a case receiving region 125. Single cases are received from the feeding device 110 by a feed wheel assembly 118, which indexes the case and feeds the case to the case receiving region 125. Each of the cases are rotated in a fixed rotational axis in the case receiving region 125 while being impinged by heat from the heat source 128. Rotation of the case in the case receiving region 125 is provided by a linear slide mechanism 300 having a roller plate 120 that supports the case in a portion of a linear travel path that moves away from the case at a point to disengage the case after heat treatment. Movement of the roller plate 120 to provide rotation and support of the case in the case receiving region 125, as well as the rotation of the feed wheel assembly 118 is governed by a drive mechanism comprising a geared timing wheel 146 that is coupled to the feed wheel assembly 118 by a common shaft to a single motor 144.
While the foregoing is directed to embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof.
