Systems and methods for tracking ammunition supply in a magazine

[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/943,796 as filed on Jun. 13, 2007; which is incorporated by reference herein.

[0002] With the increasing complexity of small arms weapons systems and the increasing complexity of urban warfare, the importance of knowing the ammunition count within a weapon's ammunition magazine becomes more relevant. Death or serious bodily injury may result if an operator of a weapon with a magazine runs out of ammunition in the duration of a small arms altercation. Current magazines with full metal casings do not allow for a direct view into the ammunition storage inside a magazine, while plastic magazines allow a limited view at the ammunition source, but not beyond where the magazine goes into the weapon and is covered by the magazine well of the weapon. In many situations, knowing when a magazine is at its last five to ten rounds is more crucial than knowing when it has lost its first five to ten rounds, as usually indicated to a limited degree by most clear magazines, in the decision process for tactical magazine replacements.

[0003] Several strategies have been developed to aid the decision to change magazines in a weapon. One of the more popular is to add tracer ammunition at a predetermined count of ammunition. However, the disadvantage of this method is that in warfare, tracer ammunition can potentially create fires in buildings. Also, besides warning the operator of the weapon of the low ammunition count, tracers can likewise warn the operator's adversaries of the operator's position in the battlefield, which could be catastrophic for the operator. Furthermore, the use of tracer ammunition does not communicate the actual ammunition count to the operator, but just a warning of a low count of it.

[0004] Another method devised to aid with the magazine replacement decision process is keeping mental track of a magazine's remaining ammunition. By keeping a count, even if not with complete accuracy, an approximation of the count will provide enough information for the magazine change decision process. However, with the intensity and high stressfulness of small arms altercation situations, this becomes an impractical practice, as even an operator's momentary loss of focus could lead to the loss of count. Likewise, if the magazine that the operator is using does not contain the initial amount of ammunition that he or she believes it initially does, the basis for which the magazine replacement would occur will be faulty.

[0005] One of the more popular methods for deciding a magazine change is for an operator to estimate the amount of ammunition he or she has based on the weight of his or her weapon with ammunition. To a limited extent, this may be a useful approximation, however with the incorporation of different add-ons onto the operator's weapon, such as night sights, scopes and other accessories, the operator's judgment of the count can be hindered, increasing the liabilities associated with this method.

[0006] Understanding some of the limitations to the current systems and methods for keeping track of unspent ammunition, one embodiment of the present invention is devised to eliminate the risks caused from the overestimation of one's ammunition count, while avoiding the waste of ammunition caused by the premature replacement of magazines due to underestimation. By doing so, the aims of one embodiment of the present invention include, but are not limited to making the use of the ammunition within a given as efficient as possible with little compromise to the magazine's weight or profile, by aiding an operator in his or her decision process for changing magazines in high stress situations.

[0007] Systems and methods for tracking ammunition supply in a magazine are disclosed herein. A method for tracking a number of cartridges remaining within a magazine, includes tracking an indicator strip coupled to a spring housed within a magazine housing, the magazine housing having the spring coupled at a first end to a follower and at a second end to a foot plate, the spring tangent to the foot plate. The method further includes selectively altering a number of cartridges in the magazine housing and monitoring an indicator window attached to the foot plate and configured to guide the indicator strip, the indicator strip aligned with a reference on the indicator window showing the number of cartridges remaining.

[0008] A magazine configured for use in a firearm, the magazine including a floor plate; a follower configured to support a cartridge; a spring coupled and tangent to the floor plate and the follower to cradle a cartridge for use in a firearm; a round counter defining an aperture, coupled to the floor plate; and a material strip having a first end and a second end, the first end coupled to the spring and the second end inserted into the aperture defined by the round counter, the material strip aligning with a marker on the round counter representing the number of cartridges remaining.

[0037] In reference to FIG. 1A and FIG. 4, an ammunition magazine is an apparatus which is used in conjunction with a firearm which dispenses ammunition into the firearm's firing chamber. Most magazines, as shown in, FIG. 1A, being composed of a protective casing 101, FIG. 4 dispense ammunition 109 by means of spring tension from a spring 103, 112 which raises a follower 102, 111 that brings up ammunition into an area of a firearm from which then can be stripped from the magazine top. When a magazine is first loaded, ammunition is horizontally placed within the magazine and pressed against a follower which in turn presses against a spring. The spring is compressed while loading and decompressed while extracting ammunition. The compression and decompression of the spring is used as means to determine an approximation for the count of ammunition within the magazine.

[0038] In reference to FIG. 2-3, the count of ammunition within the magazine is accomplished by the tilting movement of a rod piece 105 that is attached to a mount 104 that attaches to the fourth or fifth spine of the magazine spring. The lower half of the rod piece 105 has a horizontal rod 137 that goes into the grooves of a 107.

[0039] As the magazine spring compresses and decompresses, it does so at a consistent ratio which is coordinated to the number marks on the number gauge 108. The compression and decompression of the spring caused by the loading and unloading of ammunition into the magazine causes the mount 104 to move down or up respectively, causing the rod piece 105 to move rod 137 in the path dictated by the grooves of the side plate 107. This sideways movement forced by the grooves causes rod 137 to move the indicator strip piece 106 across the number gauge 108 at intervals dictated by the compression and decompression of the spring. The number of unspent ammunition within the magazine is coordinated to the number marks on the side of the number gauge 108.

[0040] The add-on variant of the main embodiment of the present invention may be attached to a pre-manufactured magazine by removing the magazine's floor plate and sliding in the hinges 138 of attachment to where the floor plate was attached to prior to its removal.

[0041] In reference to FIG. 5-7, an alternate embodiment uses the upward vertical movement of the follower 111 during unloading of ammunition from the magazine in order to activate a mechanical motor 121. Starting from a magazine at its fully loaded state, as ammunition is unloaded, a string 113 attached to the follower 111, through a loop in the follower or any other means, is pulled upwards, rotating a spindle 115 on which the string 113 is wrapped around. The rotation of the spindle 115 causes it to move rearward according to the directionality of the screw spirals on the rear half of rod 116. The rotation of the spindle 115 likewise compresses a spiral spring 114 which is mounted to the attachment casing 123 at its outer loose end with a nail 119. While rotating, the gear teeth 122 attached to the spindle 115 turn a second set of gear teeth 117 which are attached to a second spiral spring 120. This spiral spring 120 is similarly attached to the attachment casing 123 by a nail 119 at its outer loose end. Motor head 121 is likewise attached to the second spring 120 and second gear teeth 117 and is likewise turning while the magazine is being unloaded.

[0042] At a preset ammunition count that is considered by a manufacturer to be a low ammunition count, the two sets of gear teeth 117 and 122 will no longer be tangent due to the rearward movement of the spiral 114, spindle 115 and gear teeth 122 that are on the screw portion of the rod 116. This will cause spiral spring 120 to decompress because the force holding back the spring from unwinding has been lifted by the separation of the two gear teeth 122 and 117, causing the gear teeth 117 and motor head 121 attached to the spring 120 to rotate rapidly. The rapid rotating of the motor head 121 causes an uneven shift in weight throughout the attachment and the magazine, causing vibration.

[0043] When the magazine is reloaded, the string 113 attached to the magazine follower 111 will become slacked, allowing the rearward spiral spring 114 to decompress, causing the spring 114, spindle 115 and rearward gear teeth 122 to move forward on the screw portion of the rod 116. The rotating gear teeth 122 will rotate the still gear teeth 117, therefore working against the fully decompressed spring 120 that is attached to the motor head 121. Therefore, that spring 120 and gear head 121 will not rotate, but the still gear teeth 117 will move forwards on the rod 116 against a spring 118, forced by the rotating gear teeth 122 that will press against the still gear teeth 117 with the diagonal side of its teeth until the magazine is fully loaded or is empty.

[0044] In reference to FIG. 8-10, an alternate embodiment uses the upward movement of the magazine follower 111 by using a strip 126 attached to the magazine follower 111. The unloading of the magazine causes the strip 126 to rotate two spindles 131 and 141 which in turn compresses a spring forward of the magazine 129 and rotates gear teeth 134 through gear teeth 133, compressing another spring 135.

[0045] As shown in FIG. 10, the spindle 131 closer to the rear end of the magazine has little gear teeth 140 which hold on to the strip 126 by holding on to its perforated holes 139. When the ammunition count of the magazine is at its preset low count, again determined by the manufacturer, the little gear teeth 140 will let go of the perforated holes 139 on the strip 126, causing the rearward spiral spring 135 to decompress freely, spinning both sets of gear teeth 133 and 134, the spindle 131 and rod 130 to which the rearward spindle 131, forward gear teeth 133 and the motor head 128 are attached to. The uneven movement of the weight of the motor heard 128 causes vibration throughout the magazine attachment, magazine and weapon.

[0046] When the magazine is reloaded, the downward movement of the magazine follower will cause the strip 126 to become slackened, causing the forward spiral spring 129 to decompress, in turn matching up the perforated holes 139 on the strip 129 with the gear teeth 140 on the rearward spindle 131. The rearward spindle 31 will rotate causing the diagonal side of the gear teeth 133, 134 connected to the spindle 131 to force the rearward gear teeth 134 and rearward spiral spring 135 backwards against a spring 136 until the magazine is fully reloaded or reloading ceases.

[0047] The add-on variants of the alternate embodiments may be attached to a pre-manufactured magazine by removing the magazine's floor plate and sliding in the hinges 138 of attachment to where the floor plate was attached to prior to its removal. In an alternate embodiment the device may be built into a magazine.

[0048] FIGS. 11-13 show a strip reader in one embodiment. As the spring 201 of the magazine is depressed or compressed by the loading or unloading of ammunition into the magazine, its downward or upward motion is translated into a respective opposite motion by means of the flexible strip 202 which is attached to the spring 201 by a connector 203. The curvatures of the corners 204 found in a housing case 205, which is connected to the magazine case 206, facilitate the redirection of the strip's 202 movement 180 degrees. The strip's translated movement is displayed through a clear viewing window 207 where the position of its tip 209 may be used to reference the count of ammunition within the magazine by its flush position in relation to the number markings 208. The number markings 208 are set to correlate with the known and pre-measured level of ammunition that they are set to represent. The number markings 208 may likewise be color or patterns and not necessarily numbers.

[0049] FIGS. 14-16 show a round count slider in one embodiment. Sliding body 301 is attached to fixed body 302 by pegs 303 which hang on to the fixed body 302. These pegs are likewise tangent to the grooves 304 on the fixed body 302. The sliding body 301 is retracted by sliding it out along the path of the grooves 304. When the sliding body is slid out, indicator rod 322 likewise slides out by sliding out along the connector 305 connected to the strip 322.

[0050] As a magazine spring is compressed by the loading of the magazine with ammunition, a flexible material strip 320 connected to the spring by a ring 328 transfers the downward motion of the compressing magazine spring to the horizontal movement of an indicator rod 322 along a gauge 324 lined with measurement markers 326. The position of the indicator rod 322 in relation to the positions of the measurement markers 326, whose positionings are coordinated to known measures of ammunition based on the spring's compression level, communicates the level of ammunition remaining in the magazine to the operator of the magazine.

[0051] FIGS. 17-21 show a round count slider in one embodiment. As a magazine spring is compressed by the loading of the magazine with ammunition, a flexible material strip 420 connected to the spring by a ring 428 transfers the downward motion of the compressing magazine spring to the horizontal movement of an indicator rod 422 along a gauge 424 lined with measurement markers 426. The position of the indicator rod 422 in relation to the positions of the measurement markers 426, whose positionings are coordinated to known measures of ammunition based on the spring's compression level, communicates the level of ammunition remaining in the magazine to the operator of the magazine.

[0052] The round counter casing 430 is made of a clear or see-through (also opaque) material. (The angling of the top of the casing has no drastic effect on the better visibility of the indicator rod 422. A slope 432 aids in the translation of the vertical movement of indicator rod 422 to a horizontal movement by cutting down on the friction associated in the bending of the strip 422. This translation may be done without slope 432 because the material used in strip 420 is flexible enough to turn vertical movement into a horizontal one when it deflects off or bends against horizontal plane 434 through indicator rod 422. The vice versa is also true, as horizontal movement is translated into a vertical when the strip 420 through the indicator rod 422 is deflected off or bent off vertical plan 436.

[0053] While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment.