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Publication numberUS20040231220 A1
Publication typeApplication
Application numberUS 10/444,735
Publication dateNov 25, 2004
Filing dateMay 23, 2003
Priority dateMay 23, 2003
Publication number10444735, 444735, US 2004/0231220 A1, US 2004/231220 A1, US 20040231220 A1, US 20040231220A1, US 2004231220 A1, US 2004231220A1, US-A1-20040231220, US-A1-2004231220, US2004/0231220A1, US2004/231220A1, US20040231220 A1, US20040231220A1, US2004231220 A1, US2004231220A1
InventorsPatrick McCormick
Original AssigneeMccormick Patrick
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Trajectory compensating riflescope
US 20040231220 A1
Abstract
Disclosed is a riflescope that incorporates physical measurements and user specific firearm parameters to calculate and designate the target impact point. The scope incorporates a laser range finder with the receiver integrated into the visual sight path thus utilizing the large objective aperture to collect as much reflected light as possible. This ensures long distance operation while maintaining a compact form factor. The line-of-sight laser distance and inclination angle are measured and used to calculate the actual horizontal target distance. A user interface keypad and display provide a mechanism to enter in firearm and ammunition specific parameters such as muzzle velocity and ballistic coefficient. A barometric pressure and temperature sensor measure the actual air density; this and the user entered ballistic coefficient quantify the resulting bullet drag and thus resulting final velocity. All these physical measurements and user specific parameters are utilized to calculate the final bullet impact point. This compensated aim point is indicated by automatically adjusting the elevation reticle.
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Claims(14)
1-4. (canceled).
5. A scope assembly adapted for rigid attachment to a firearm, the scope assembly comprising:
an optical tube assembly having an objective lens and an eyepiece received along a longitudinal axis of the optical tube assembly defining a line of sight between the eyepiece and the objective lens;
a reticle received in the optical tube assembly between the objective lens and the eyepiece;
a laser transmitter operable to send a beam of light toward an intended target;
a laser receiver maintained out of said line of sight;
a reflection filter received between the objective lens and the eyepiece and in said line of sight, the reflection filter having a surface oblique to the longitudinal axis of the optical tube assembly to reflect a beam reflected from the intended target to the laser receiver while allowing visible light to pass between the eyepiece and the objective lens to provide an unobstructed viewing path through the optical tube assembly; and
a controller in operable communication with the laser transmitter and the laser receiver to facilitate determining the linear distance between the firearm and the intended target and in operable communication with reticle to facilitate automatic adjustment of the reticle to a compensated aim point while the optical tube assembly remains rigidly fixed to the firearm.
6. The scope assembly of claim 5 further comprising an angle transducer in operable communication with the controller to send a signal to the controller indicating the orientation of the scope assembly relative to a horizontal plane.
7. The scope assembly of claim 6 wherein the controller is operable to determine a horizontal distance component and a vertical distance component for automated reticle adjustment as a function of the signal provided by the angle transducer.
8. The scope assembly of claim 5 further comprising a motor in operable communication with the reticle and the controller to receive signals from the controller and to automatically adjust the reticle upwardly or downwardly within the optical tube assembly as a function of said signals.
9. The scope assembly of claim 8 further comprising an adjuster manually moveable in one direction to move the reticle upwardly within the optical tube assembly and manually moveable in another direction to move the reticle downwardly within the optical tube assembly and the motor being in operable communication with the adjuster to automatically drive the adjuster in one of said directions in response to receiving said signals from the controller.
10. The scope assembly of claim 9 further comprising a pinion gear and a bevel gear in meshed engagement with one another, the pinion gear being operably attached to the motor for conjoint rotation with the motor and the bevel gear being operably attached to the adjuster and moving in response to the movement of the pinion gear.
11. The scope assembly of claim 5 wherein the surface of the reflection filter is inclined 45 degrees relative to the longitudinal axis.
12. The scope assembly of claim 5 further comprising a filter lens received between the reflection filter and the laser receiver, the filter lens having an arcuate surface causing the reflected beam of light from the reflection filter to converge toward the laser receiver.
13. The scope assembly of claim 5 wherein the reflection filter allows visible light to pass from the objective lens to the eyepiece.
14. The scope assembly of claim 5 wherein the reticle is in said line of sight between the reflection filter and the eyepiece.
15. The scope assembly of claim 14 wherein the reticle is automatically adjusted in response to a signal from the controller.
16. The scope assembly of claim 5 further comprising a barometric pressure transducer in operable communication with the controller to facilitate automatic adjustment of the reticle to a compensated aim point.
17. The scope assembly of claim 5 further comprising a temperature sensor in operable communication with the controller to facilitate automatic adjustment of the reticle to a compensated aim point.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] Not Applicable

FEDERALLY SPONSORED RESEARCH

[0002] Not Applicable

SEQUENCE LISTING OR PROGRAM

[0003] Not Applicable

BACKGROUND OF THE INVENTION—FIELD OF INVENTION

[0004] This invention relates generally to targeting devices used to aim firearms and the like, and more specifically to a riflescope that calculates a trajectory and indicates a compensated aim point.

BACKGROUND OF THE INVENTION

[0005] Since the introduction of firearms, users have struggled to compensate for the effects of gravity. Gravity acting on the projectile during its time-of-flight causes a vertical drop. The time-of-flight is a function of the horizontal target distance, initial velocity, and deceleration due to the aerodynamics of the projectile and drag imparted by the air resistance. This problem has become increasingly challenging as modern improvements in firearms and ammunition have increased their effective range.

[0006] Originally firearms were constructed with iron sights. This made targeting difficult at longer ranges. The problem was partially solved through the introduction of riflescopes with telescopic sights; these provided a detailed view of the target at longer ranges. However this introduced a new problem, the need to adjust the aim point to compensate for the effects of gravity on the projectile. Initially shooting enthusiasts used a sight-in method where the projectile trajectory was determined at several ranges. This method proved problematic since the user was required to estimate the horizontal target distance and manually adjust the aim point. In an attempt to improve the target range estimation riflescopes were introduced with mil-dot reticles. Although this provided a better method of estimating target distance, it still required the user to manually adjust the aim point.

[0007] Thereafter, inventors proposed more advanced firearm range estimation and compensation devices. A search of prior art did not disclose any patents that read directly on the claims of the instant invention. U.S. Pat. No. 5,771,623 to Pernstich et al. (Jun. 30, 1998) discloses a complex telescopic sight that integrates the laser transmitter, laser receiver and measured range display into the visual sight path. Although this device as described provides a method for accurately measuring the line-of-sight range it is still prone to inaccuracies because it requires the user to estimate the affects of uphill/downhill shooting, variations in muzzle velocity, and variations in ballistic coefficient. In addition, the incorporation of the laser transmitter and display into the visual sight path requires a more complex alignment and assembly resulting in a fragile arrangement that is costly to manufacture.

[0008] U.S. Pat. No. 6,252,706 to Kaladgew (Jun. 26, 2001) discloses a range compensating telescopic sight with automatic aiming and adjustment. Although this device as described indicates the use of a stepper motor to automatically adjust the original position of the sight to the required point of aim. As proposed the device actually moves the entire riflescope assembly, this is more complicated than necessary and thus more expensive. The simpler method of adjusting the aim point is to couple the stepper motor directly to the manual elevation adjustment knob contained on conventional riflescopes.

[0009] U.S. Pat. No. 6,269,581 to Groh (Aug. 7, 2001) discloses a range compensating riflescope that calculates and automatically indicates an impact point with a display integrated into the visual sight path. As described the display indicates the calculated impact point with a horizontal line, however to provide the necessary accuracy this display would need a very fine resolution resulting in higher component costs. In addition, the optical alignment and mounting of the display to provide an adequate level of accuracy would be complex and costly to manufacture. As with the previous invention, this prior art fails to identify a method to compensate for the affects of shooting uphill or downhill. As described the invention uses the bullet weight as the parameter of interest to determine the deceleration due to drag from air resistance. However, the actual parameter that characterizes the deceleration due to drag from air resistance is the bullets commonly published ballistic coefficient. In addition, the invention describes the calculation is based on a user input parameter of elevation to factor in the air pressure and resulting resistance. However, air pressure is dependent on elevation, current weather conditions, and temperature. Therefore a much simpler and more accurate method is to incorporate a barometric pressure and temperature sensor to calculate the current air density.

[0010] While several features exhibited within these references are incorporated into this invention, alone and in combination with other elements, the present invention is sufficiently different so as to make it distinguishable over the prior art.

BACKGROUND OF THE INVENTION—OBJECTS AND ADVANTAGES

[0011] Accordingly, several objects and advantages or my invention are:

[0012] (a) to provide increased effective range in a compact form factor by utilizing the large visual sight path objective aperture to collect a greater amount of reflected laser light;

[0013] (b) to provide improved accuracy for uphill and downhill operation by incorporating laser range finding technology and inclination angle measurement to calculate the horizontal distance to the selected target;

[0014] (c) to provide improved accuracy by calculating the compensated aim point with user entered muzzle velocity;

[0015] (d) to provide improved accuracy by calculating the compensated aim point with user entered ballistic coefficient;

[0016] (e) to provide improved accuracy by calculating the compensated aim point using a barometric pressure and temperature sensor to determine the air density and resulting drag;

[0017] (f) to provide improved accuracy by automatically adjusting the elevation reticle to indicate the compensated aiming point;

[0018] (g) to provide an improved targeting device that can be used in a manner identical to that of a conventional riflescope in the event of battery failure or if so desired;

[0019] Further objects and advantages are to provide an improved targeting device that is lightweight, compact and easy to use. Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.

SUMMARY

[0020] In accordance with the present invention a trajectory compensating riflescope that is comprised of an otherwise traditional riflescope that incorporates measurements to determine the horizontal target distance and air density. In addition, a user interface is provided to enter firearm and ammunition specific parameters such as muzzle velocity and ballistic coefficient. These measurements and parameters are applied to calculate and automatically adjust the elevation reticle to a compensated aim point.

DRAWINGS—FIGURES

[0021]FIG. 1A is a left-rear perspective view of a trajectory compensating riflescope, according to the preferred embodiment of the present invention.

[0022]FIG. 1B is a right-front perspective view of a trajectory compensating targeting device, according to the preferred embodiment of the present invention.

[0023]FIG. 2 is a left-rear exploded perspective view of a trajectory compensating targeting device, according to the preferred embodiment of the present invention.

[0024]FIG. 3 is a left-rear exploded perspective view of the top protective housing assembly, according to the preferred embodiment of the present invention.

[0025]FIG. 4 is an exploded perspective view of the internal scope assembly, according to the preferred embodiment of the present invention.

[0026]FIG. 5 is an exploded perspective view of the bottom protective housing assembly, according to the preferred embodiment of the present invention.

[0027]FIG. 6 is an exploded perspective view of the display assembly, according to the preferred embodiment of the present invention.

[0028]FIG. 7 is an exploded perspective view of the objective section assembly, according to the preferred embodiment of the present invention.

[0029]FIG. 8 is an exploded perspective view of the receiver assembly, according to the preferred embodiment of the present invention.

[0030]FIG. 9 is a cross sectional view of the receiver assembly, according to the preferred embodiment of the present invention.

[0031]FIG. 10 is an exploded perspective view of the automatic elevation adjustment assembly, according to the preferred embodiment of the present invention.

[0032]FIG. 11 is an exploded perspective view of the rear scope assembly, according to the preferred embodiment of the present invention.

[0033]FIG. 12 is an exploded perspective view of the transmitter assembly, according to the preferred embodiment of the present invention.

[0034]FIG. 13 is a block diagram of the electronics and their associated hardware interface, according to the preferred embodiment of the present invention.

DRAWINGS—Reference Numerals

[0035]20. Trajectory Compensating Riflescope Assembly

[0036]22. Conventional Riflescope Manual Reticle Adjustment Dust Cap

[0037]24. Power Switch

[0038]26. Battery Compartment Cover

[0039]30. Upper Protective Housing Assembly

[0040]32. Upper Protective Housing

[0041]34. Data Entry Button Keypad

[0042]36. Display Hinge Pin

[0043]40. Internal Trajectory Compensating Riflescope Assembly

[0044]50. Lower Protective Housing Assembly

[0045]52. Lower Protective Housing

[0046]54. Activation Button Keypad

[0047]60. Display Assembly

[0048]62. Display Bezel

[0049]64. LCD Display

[0050]66. Display Housing

[0051]70. Objective Section Assembly

[0052]72. Conventional Riflescope Objective Tube Assembly

[0053]74. Battery Holder Bracket

[0054]75. Battery Compartment

[0055]76. Front Bracket

[0056]77. User Interface Printed Circuit Board

[0057]79. Conventional Riflescope Objective Lens Assembly

[0058]79. Transmitter Protective Lens

[0059]80. Receiver Assembly

[0060]81. Laser Receiver

[0061]83. Main Printed Circuit Board Standoff

[0062]83. Receiver Mount

[0063]84. Receiver Lens Collet

[0064]85. Plano-Convex Narrow Pass-Band Filter Lens

[0065]86. Receiver Housing

[0066]87. Notch Reflection Filter

[0067]88. Center Tube Mount

[0068]90. Automatic Elevation Reticle Adjustment Stepper Motor Assembly

[0069]92. Stepper Motor

[0070]94. Stepper Motor Mount

[0071]96. Bevel Pinion Gear

[0072]100. Rear Scope Section Assembly

[0073]101. Manual Elevation Adjustment Knob

[0074]102. Automatic Elevation Adjustment Gear

[0075]104. Conventional Riflescope Eyepiece Assembly

[0076]105. Conventional Riflescope Magnification Adjustment Knob Assembly

[0077]106. Conventional Riflescope Center Tube Assembly

[0078]108. Conventional Riflescope Manual Windage Reticle Adjustment Knob Assembly

[0079]110. Transmitter Assembly

[0080]112. Laser Collet

[0081]114. Laser Transmitter

[0082]116. Collimating Lens

[0083]118. Transmitter Housing Tube

[0084]120. Main Printed Circuit Board Assembly

[0085]121. Micro-Controller

[0086]122. Stepper Motor Driver

[0087]123. Pulsed Laser Driver

[0088]124. Detection Discriminator

[0089]125. Time-of-Flight Detection

[0090]126. Tilt Angle Transducer

[0091]127. Barometric Pressure Transducer

[0092]128. Temperature Sensor

[0093]129. Nonvolatile Memory

DETAILED DESCRIPTION—FIGS. 1-8 & 10-12—PREFERRED EMBODIMENT

[0094] A preferred embodiment of the trajectory compensating riflescope, hereinafter riflescope 20 of the present invention is illustrated in FIG. 1A (left rear) and FIG. 1B (right front) perspective views.

[0095] As shown in FIG. 2, an upper protective housing, shell, or enclosure assembly 30 is secured to an internal riflescope assembly 40 using eight flathead machine screws, four threaded through the left side and four threaded through the right side. The manual reticle adjustment dust caps 22A and 22B consisting of formed and machined thin wall aluminum are threaded onto both the top of the upper protective housing assembly and center tube assembly sealing against the protective housing assemblies creating a weather tight seal. A power switch 24 is snapped into the upper protective housing assembly sealing tightly to protect against weather. A battery compartment cover 26 consisting of injection molded plastic is fastened to the internal scope assembly using two socket head cap screws creating a weather tight seal with the upper protective housing. A lower protective housing assembly 50 has a molded lip that overlaps the upper protective housing assembly, creating a weather tight seal and covering the eight flathead machine screws. The lower housing assembly is secured to the internal scope assembly using eight flathead machine screws threaded up through the bottom. The top and bottom housings seal to form a weather tight and protective shell for the various internal riflescope components.

[0096] As shown in FIG. 3, an upper protective housing 32 is constructed of injection-molded plastic providing a shell that is rigid and can absorb impact and repel abrasion. A data entry button keypad 34 consisting of molded silicone rubber is fastened to the internal surface of an upper protective housing using an adhesive, this forms a weather tight seal. A display hinge pin 36 consisting of aluminum rod stock is inserted through the upper protective housing and a display assembly 60 providing a pivot for opening and closing the display assembly.

[0097] As shown in FIG. 4, an objective section assembly 70 is secured to the front of a receiver assembly 80 using two setscrews, one threaded through the left side and one threaded through the right side. A rear riflescope section assembly 100 is secured to the rear of the receiver assembly using two setscrews, one threaded through the left side and one threaded through the right side. An automatic elevation reticle adjustment assembly 90 is slide over and positioned onto the rear scope section assembly then secured using two setscrews, one threaded through the left side and one threaded through the right side. A main printed circuit board assembly 120 is fastened to the top of the objective section assembly and the receiver assembly using four pan-head machine screws.

[0098] As shown in FIG. 5, a bottom protective housing 52 is constructed of injection-molded plastic providing a shell that is rigid and can absorb impact and repel abrasion. An activation button keypad 54 consisting of molded silicone rubber is attached to the internal surface of the bottom protective housing using an adhesive forming a weather tight seal.

[0099] As shown in FIG. 6, a display housing 62 is constructed of injection-molded plastic providing a shell that that is rigid and can absorb impact and repel abrasion. A display 64 is positioned into a cavity of the display housing. A display bezel 66 constructed of injection-molded plastic is snapped into the display housing. This locates and secures the display by sandwiching it between the display housing and display bezel.

[0100] As shown in FIG. 7, a conventional riflescope objective tube assembly 72 is constructed of thin wall aluminum tubing. A battery compartment bracket or mount 74 consisting of machined aluminum is fastened to the objective tube using two setscrews, one threaded through the left side and one threaded through the right side. A 9-Volt battery compartment or holder 75 consisting of injection molded plastic and metal terminal contacts is fastened to the battery compartment bracket using two flathead machine screws, one located on a bottom tab and one located on a rear tab. A front bracket 76 consisting of machined aluminum is fastened to the objective tube using two setscrews, one threaded through the left side and one threaded through the right side. A button printed circuit board 77 is attached to the front bracket using tow pan-head machine screws and the battery compartment bracket using two pan-head machine screws. A conventional riflescope objective lens assembly 78 consisting of a plano-convex shaped glass lens held in a threaded metallic ring is positioned using internal threads contained in the front of the objective tube. A transmitter protective lens 79 consisting of glass is attached to the face of the front bracket with adhesive creating a weather tight seal. A laser transmitter assembly 110 is threaded into the rear of the front bracket.

[0101] As shown in FIG. 8, a receiver mount 83 consisting of machined aluminum contains a cavity for locating and securing a laser receiver, photodiode, or photo-detector 81. A set of two printed circuit board standoffs 82 used to secure the main printed circuit board are threaded into the top of the receiver mount. The receiver mount is secured to the top of a receiver housing 86 consisting of machined aluminum using four socket head cap screws located in each of the corners. A plano-convex narrow pass-band filter lens 85 consisting of thin film coated glass is located in a cavity in the receiver housing. The lens is secured into the receiver housing with a threaded receiver collet 84 also consisting of machined aluminum. A notch reflection filter 87 is positioned at a 45° angle and secured by sandwiching it between the receiver housing and a center tube mount 88 consisting of machined aluminum. The center tube mount is fastened to the receiver housing with four socket head cap screws, one located in each corner.

[0102] As shown in FIG. 10, a stepper motor 92 is fastened to a motor mount 94 consisting of machined aluminum using two pan-head machine screws. A bevel pinion gear 96 consisting of machined plastic is attached to the stepper motor with a keyed press fit.

[0103] As shown in FIG. 11, a manual elevation adjustment knob 101 consisting of machined aluminum round stock is joined to a bevel ring gear 102 consisting of machined plastic. These two components are fastened to a conventional riflescope center tube assembly 107 using two socket head cap screws. A conventional riflescope eyepiece assembly 104 is threaded onto the conventional riflescope center tube assembly. A conventional riflescope magnification adjustment knob assembly 105 consisting of injection molded plastic is attached to the conventional riflescope center tube assembly using a single socket head cap screw. A conventional riflescope manual windage adjustment knob assembly 108 consisting of machined aluminum round stock is attached to the conventional riflescope center tube assembly using two socket head cap screws.

[0104] As shown in FIG. 12, a laser transmitter or diode 114 is loaded into the rear of a transmitter housing tube or mount 116 consisting machined aluminum round stock. The laser transmitter is locked into place by sandwiching it between an internal shoulder in the transmitter housing tube and a threaded laser collet 112 consisting of machined aluminum round stock. A collimating lens 118 consisting of a glass lens and a threaded outer metal ring is positioned by rotating it inside the internally threaded transmitter housing. Once the desired location is achieved the collimating lens is locked into place using adhesive.

[0105] Operation—FIGS. 2-13

[0106] Once the trajectory compensating riflescope is mounted to the firearm the user must perform a zeroing calibration operation, this procedure is identical to that used for conventional riflescopes. The manual elevation adjustment knob 101 and the windage adjustment knob 108 (FIG. 11) are rotated the corresponding number of clicks to zero out the mounting position. This also establishes a sighted in distance when the trajectory compensating riflescope is used as a conventional riflescope.

[0107] When the electronics are not enabled, the manner of using the automatic trajectory compensating targeting riflescope is identical to that for riflescopes in present use. The operation as a normal riflescope is necessary to ensure useful operation in the event of battery failure.

[0108] To make use of the automatic compensation mode, the user must toggle the power switch 24 (FIG. 2) to the on position. As shown in FIG. 13, this will cause the micro-controller 121 to read the muzzle velocity and ballistic coefficient parameters from the nonvolatile memory 129. These parameters must be previously entered using the data entry button keypad 34 (FIG. 3) prior to actual use by opening the hinged display assembly 60, and stepping through preprogrammed menu options shown on the display 64 (FIG. 6).

[0109] The user then views the intended target through eyepiece 104 (FIG. 11) and lines up the reticle center point with the intended target. The user then depresses the activation button 54 (FIG. 5), triggering the automatic compensation electronics. As depicted in the electronics block diagram in FIG. 13, the micro-controller 121 will generate a trigger that is routed into both the pulsed laser driver 123 and time-of-flight detection circuit 125. In parallel, this trigger starts the high-speed timer in the time-of-flight detection circuit and signals the pulsed laser driver to generate a pulse of high current into the laser transmitter 104. The collimating lens 118 (FIG. 12) tightly focuses the pulsed laser light providing a low divergent beam that provides long-range operation.

[0110] The laser light is then reflected off the target, objective lens 78 (FIG. 7) collects and focuses the reflected light into the receiver section assembly 80 (FIG. 4). As shown in FIGS. 8 and 9, the notch reflection filter 87 housed in the receiver section assembly reflects the laser light straight up while passing the visual light axially through to the rear scope section assembly 100 (FIG. 4). The laser light is then filtered a second time and focused onto the photodiode as it passes through the plano-convex narrow-band filter lens 85. Once the reflected laser light exceeds a calibrated threshold in the detection discriminator 124 (FIG. 13) a trigger is sent to stop the high-speed timer in the time-of-flight detection circuit.

[0111] As shown in FIG. 13, the micro-controller 121 will then receive a trigger from the time-of-flight detection circuit 125 indicating that a measurement is complete. The micro-controller then samples the inclination angle transducer 126. The measured line-of-sight distance and inclination angle are used to calculate the actual horizontal target distance. In addition, the microcontroller samples the barometric pressure transducer 127 and temperature sensor 128; these two values are applied to the ideal gas law equation to calculate the actual air density thus factoring in the air resistance that will affect the flight velocity. The microcontroller then uses the measured data and user specific parameters to calculate the elevation reticle adjustment necessary to precisely impact the target.

[0112] Lastly, the micro-controller signals the stepper motor driver circuit 122 to drive the stepper motor 92 (FIG. 10) to the position where the elevation reticle as viewed through the eyepiece will precisely aligned with the projectile impact point on the target. The elevation reticle will return to the default or zero calibration position after switching off the power switch 24 (FIG. 2).

[0113] Advantages

[0114] From the descriptions above, a number of advantages of my trajectory compensating riflescope become evident:

[0115] (a) The integration of the laser receiver system into the viewing optics reduces the overall form factor and weight. In addition, using the large aperture of the objective lens to collect the reflected laser light provides for lower light level detection and thus greater effective range.

[0116] (b) Incorporating the user settable muzzle velocity value provides a critical parameter in calculating the time over which the projectile will be influenced by gravity thus resulting in a more accurate determination of the final impact point.

[0117] (c) Incorporating the user settable ballistic coefficient value provides a critical parameter in calculating the time over which the projectile will be influenced by gravity thus resulting in a more accurate determination of the final impact point. This value indicates how well a specific bullet can overcome air resistance and maintain flight velocity.

[0118] (d) Incorporating the measurement of the barometric pressure and temperature values provides a critical parameter in calculating the time over which the projectile will be influenced by gravity thus resulting in a more accurate determination of the final impact point. These two values are applied to the ideal gas law equation to calculate the actual air density thus factoring in the air resistance that will affect the flight velocity.

[0119] (e) Gravity only affects the projectile over the horizontal distance traveled. Implementing both the line of sight laser distance measurement and inclination angle provides a method to determine the horizontal distance when shooting uphill or downhill.

[0120] (f) Indicating the compensated aim point by automatically adjusting the elevation reticle eliminates the need to guess at the adjusted aim point.

[0121] (g) Providing operation as a conventional riflescope ensures useful functionality in the event of battery failure.

[0122] (h) The manual windage and elevation adjustments provide a mechanism to calibrate the zero aim point at a given target distance thus compensating for variability in mounting position on the firearm.

[0123] Conclusion, Ramifications, and Scope

[0124] Thus the reader will see that the trajectory compensating riflescope of the invention provides a compact, lightweight, yet economical device that is highly accurate and easy to use.

[0125] While my above description contains many specificities, these should not be construed as limiting the scope of the invention, but rather as exemplification of one preferred embodiment thereof. Many other variations are possible. For example, the laser transmitter could also be integrated into the visual sight path. The range finding apparatus could be modular and not integrated into the visual sight path. The laser distance measurement method could implement a phase shift method instead of pulsed time of flight method. The material choices could vary for each of the individual components. The use of a conventional riflescope could be eliminated to change the overall device form factor. The accuracy could be sacrificed by eliminating the barometric pressure, temperature, and inclination angle sensors to reduce overall cost. The user interface could be simplified or eliminated to reduce cost. The user specific parameters such as muzzle velocity and ballistic coefficient could be entered using a computer interface or preset at the factory. The user input could be simplified by using a lookup table to identify the muzzle velocity and ballistic coefficient values for entered firearm and ammunition types. Although not implemented due to the additional cost, an anemometer could be added to measure the head wind and compensate for the additional drag thus providing greater accuracy. In addition, an anemometer that measures and compensates for crosswind could be added and used to automatically adjust the windage reticle. The method of indicating the compensated aim point could consist of a secondary elevation and/or windage reticle.

[0126] Accordingly, the scope of the invention should be determined not by the embodiment(s) illustrated, but by the appended claims and their legal equivalents.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7292262Jul 21, 2003Nov 6, 2007Raytheon CompanyElectronic firearm sight, and method of operating same
US7661348 *Oct 26, 2007Feb 16, 2010Heckler & Koch GmbhExchangeable barrel modules for firearms
US7703679Feb 3, 2006Apr 27, 2010Burris CorporationTrajectory compensating sighting device systems and methods
US7806331Nov 30, 2005Oct 5, 2010Windauer Bernard TOptical sighting system
US7859650May 11, 2009Dec 28, 2010Bushnell Inc.Method, device, and computer program for determining a range to a target
US8033464Aug 27, 2010Oct 11, 2011Windauer Bernard TOptical sighting system
US8201741Dec 28, 2009Jun 19, 2012Burris CorporationTrajectory compensating sighting device systems and methods
US8317100Sep 6, 2011Nov 27, 2012Aoss, LlcOptical sighting system
US8408460 *Jun 3, 2010Apr 2, 2013United States Of America As Represented By The Secretary Of The NavyAuto adjusting ranging device
US8833655May 25, 2012Sep 16, 2014Burris CorporationMagnification compensating sighting systems and methods
US20110167708 *Jan 12, 2010Jul 14, 2011Carson ChengRubber Armored Rifle Scope with Integrated External Laser Sight
US20110297744 *Jun 3, 2010Dec 8, 2011John Felix SchneiderAuto adjusting ranging device
US20140182179 *Dec 31, 2012Jul 3, 2014John Francis McHaleLocation-Based Small Arms Control System
EP1748273A1 *Jul 25, 2005Jan 31, 2007Bushnell Performance OpticsTelescopic sight and method for automatically compensating for bullet trajectory deviations
EP1804017A1 *Dec 8, 2006Jul 4, 2007Bushnell CorporationTelescopic sight and method for compensating for bullett trajectory deviations
EP1817538A2 *Nov 30, 2005Aug 15, 2007Bernard Thomas WindauerOptical sighting system
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Classifications
U.S. Classification42/120
International ClassificationF41G1/473
Cooperative ClassificationF41G1/473, F41G3/08, F41G3/06
European ClassificationF41G3/06, F41G3/08, F41G1/473