Lead calculator

A lead calculator for calculating the required lead when shooting a projectile at a moving target, as a function of three parameters, the parameters including target speed, target range and projectile speed, the calculator comprising:

• five scales including
• a first logarithmic scale having corresponding indicia designating quantitative representations of target speed,
• a second logarithmic scale having corresponding indicia designating quantitative representations of target range,
• a third logarithmic scale having corresponding indicia designating quantitative representations of projectile speed
• a fourth logarithmic scale having corresponding indicia designating quantitative representations of required lead and
• a reference scale;
• a first member;
• a second member slidable in relation to said first member;
• said first, second, third and fourth logarithmic scales being disposed on said first members;
• said reference scale being disposed on said second member;
• said first through fourth scales having relative positions and such relative proportions that the product of the target speed and the target range divided by the projectile speed may be readily determined by moving said second member in relation to said first member to a first relative position determinable from the value of two of said parameters, noting a first location on said reference scale adjacent a location on one of said first through fourth scales corresponding to the value of one of said parameters and moving said first member to a second relative position determinable from said noted first location and the value of said one of said parameters.

A device for calculating the required lead when shooting a projectile at a moving game, as a function of game speed, game range and projectile speed, comprising:

• a first logarithmic scale having numerical indicia associated therewith corresponding to game speed;
• a second logarithmic scale having numerical indicia associated therewith corresponding to the required lead;
• a third logarithmic scale having numerical indicia associated therewith corresponding to game range;
• a fourth logarithmic scale having numerical indicia associated therewith corresponding to projectile speed;
• descriptive indicia formed on said first logarithmic scale for designating predetermined intervals of game speed corresponding to particular modes of movement of said game such as walking, trotting, running and flying;
• and
• a reference scale disposed on a first member;
• said first, second, third and fourth scales and said descriptive character indicia being formed on a second member and disposed in physical proximity with each other so that they are correlated, the correlated numerical value associated with the required lead scale being readily determinable if the correlated numerical value associated with the projectile speed scale, the correlated numerical value associated with the game range and either the correlated numerical value or the interval descriptive indicia formed on the game speed scale are known.

A device for calculating the required lead when shooting a projectile at a moving target, as a function of target speed, target range and projectile speed, comprising:

• at least one member;
• four scales including
• a first logarithmic scale having numerical indicia associated therewith corresponding to target speed,
• a second logarithmic scale having numerical indicia associated therewith corresponding to the required lead,
• a third logarithmic scale having numerical indicia associated therewith corresponding to target range, and
• a fourth logarithmic scale corresponding to projectile speed;
• and
• a plurality of indicia respectively corresponding to different projectiles disposed at predetermined locations on said third scale corresponding to the normal speed of said projectiles when they are shot;
• said first, second, third and fourth scales being formed on said at least one member and disposed in physical proximity with each other so that they are correlated, the correlated numerical value associated with the required lead scale being readily determinable if the correlated numerical value associated with the target range scale, the correlated numerical value associated with the target speed scale and the particular projectile being shot are known.

A method for calculating required lead in predetermined units of linear distance as a function of target speed, target range and projectile speed for shooting a projectile at a moving target, utilizing a first member;

• a second member slidable in relation to said first member;
• a first logarithmic scale having indicia representing target range along a line of sight from the projectile launching point to the point of intended impact, a second logarithmic scale having indicia representing target speed;
• a third logarithmic scale having indicia representing required lead in terms of distance perpendicular to said line of sight;
• and a fourth logarithmic scale representing projectile speed, said scales being disposed on at least one of said first and second members in such proximity to each other that they are correlated;
• and non-logarithmic marking indicia disposed on said second member for marking the calculation of required lead when said second member is moved relative to said first member, the method comprising the step of:
• sliding said slide member in relation to said first member so as to align said marking indicia disposed on said second member with the numerical indicia corresponding to the required lead, the target speed and the target range, the required lead being readily determinable thereby.

A method for calculating the required lead when shooting a projectile at a moving target as a function of three parameters, the parameters being target speed, target range and projectile speed, utilizing a calculator comprising at least five scales including a first scale having corresponding indicia of target speed, a second logarithmic scale having corresponding indicia designating quantitative representations of target range, a third logarithmic scale having corresponding indicia designating quantitative representations of projectile speed, and a fourth logarithmic scale having corresponding indicia designating quantitative representations of required lead;

• said lead indicia and said target indicia having differing units of length, said target speed indicia and said projectile speed indicia having differing units of speed;
• the calculator further comprising a first member and a second member slidable in relation to said first member, said first through fourth logarithmic scales being disposed on said first member and being structurally correlated a reference scale formed on said second member;
• said method comprising the steps of:
• (1) sliding said second member in relation to said first member so as to determine a point on said reference scale corresponding to the product of the target speed and the target range;
• and
• (2) sliding said second member in relation to said point on said first member in order to determine a value equal to the product of target speed and target range divided by the projectile speed.

A method of calculating required lead, as a function of three parameters including target speed, target range and projectile speed, when shooting at a movable target with any of a variety of projectiles utilizing a calculating device comprising at least five scales including a first logarithmic scale having corresponding indicia designating quantitative representations of target speed, a second logarithmic scale having corresponding indicia designating quantitative representations of target range, a third logarithmic scale having corresponding indicia designating quantitative representations of projectile speed, a fourth logarithmic scale having corresponding indicia designating quantitative representations of required lead and a reference scale;

• a first member;
• a second member slidable in relation to said first member;
• said first, second, third and fourth logarithmic scales being structurally correlated and being disposed on said first member, said second member having disposed thereon said reference scale, said method comprising the steps of:
• (1) moving said second member in relation to said first member to a first relative position determinable from the value of one of said three parameters, a first location on said reference scale there being disposed adjacent a second location on said first member, said second location on one of said first, second or fourth logarithmic scales corresponding to the value of a second one of said three parameters;
• and
• (2) moving said first member to a second relative position determinable from said noted first location and the value of a third one of said three parameters.