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A pneumatically powered pole saw, comprising: an extendable pole; a head member secured to the extendable pole; a cutting blade movably mounted to the head member; a piston linked to the cutting blade; a reciprocating valve disposed in the head member configured to release compressed gas into the pi

A pneumatically powered pole saw, comprising: an extendable pole; a head member secured to the extendable pole; a cutting blade movably mounted to the head member; a piston linked to the cutting blade; a reciprocating valve disposed in the head member configured to release compressed gas into the piston chamber on one side of the piston when the reciprocating valve is in a first position causing the cutting blade to move in a first cutting direction, when the cutting blade reaches the limit of travel in the first direction, the reciprocating valve releases compressed gas into the piston chamber on another side of the piston causing the cutting blade to move in a second cutting direction.

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1. A pneumatically powered pole saw, comprising: an extendable pole;a head member secured to the extendable pole;a cutting blade movably mounted to the head member;a piston linked to the cutting blade, the piston being slidably received within a piston chamber of the head member;a reciprocating valv

1. A pneumatically powered pole saw, comprising: an extendable pole;a head member secured to the extendable pole;a cutting blade movably mounted to the head member;a piston linked to the cutting blade, the piston being slidably received within a piston chamber of the head member;a reciprocating valve disposed in the head member, the reciprocating valve being configured for movement between a first position and a second position wherein the reciprocating valve releases a portion of a source of compressed gas into the piston chamber on one side of the piston when the reciprocating valve is in the first position causing the cutting blade to move in a first cutting direction towards a limit of travel in the first cutting direction and a first check valve provides fluid communication to the piston chamber on another side of the piston causing the reciprocating valve to move from the first position towards the second position, when the cutting blade reaches the limit of travel in the first direction, the reciprocating valve releases another portion of the source of compressed gas into the piston chamber on the another side of the piston when the reciprocating valve is in the second position causing the cutting blade to move in a second cutting direction opposite to the first cutting direction and towards a limit of travel in the second cutting direction and a second check valve provides fluid communication to the piston chamber on the one side of the piston, the reciprocating valve moving from the second position towards the first position when the cutting blade reaches a limit of travel in the second direction, wherein the reciprocating valve comprises an actuator on either side of the reciprocating valve and a portion of the cutting blade is slidably received on an assembly between a first stop member and a second stop member fixed to the assembly, the assembly being slidably mounted in the head member, wherein contact of the portion of the cutting blade with either the first stop member or the second stop member causes the assembly to move and contact the actuator on either side of the reciprocating valve moving the reciprocating valve between the first position and the second position. 2. The pneumatically powered pole saw as in claim 1, wherein the assembly further comprises a main rod member for slidably receiving the portion of the cutting blade and a pair of contact members each fixedly secured to the main rod member, each one of the pair of contact members being configured to contact one of the actuators as the portion of the blade contacts either the first stop member or the second stop member and wherein the pair of contact members are not fixedly secured to the actuators such that an end portion of each of the pair of contact members is in a spaced relationship with respect to one of the actuators when the portion of the blade makes contact with either the first stop member or the second stop member. 3. The pneumatically powered pole saw as in claim 1, wherein the assembly opens either the first check valve or the second check valve as the cutting blade contacts the first stop member and the second stop member. 4. The pneumatically powered pole saw as in claim 3, wherein the assembly, the reciprocating valve, the first check valve and the second check valve are located in the head member. 5. The pneumatically powered pole saw as in claim 1, wherein the source of compressed gas is secured to the extendable pole at a position remote from the head member. 6. The pneumatically powered pole saw as in claim 1, wherein the reciprocating valve is a slide valve coupled to the cutting blade and movement of the cutting blade actuates the slide valve. 7. The pneumatically powered pole saw as in claim 6, wherein the slide valve comprises a slide coupled to the cutting blade and a first valve for releasing the source of compressed gas into one side of the piston chamber and a second valve for releasing the source of compressed gas into another side of the piston chamber, wherein movement of the slide between a first position and a second position alternately opens and closes the first valve and the second valve respectively. 8. The pneumatically powered pole saw as in claim 7, wherein a portion of the cutting blade is slidably received on the slide and the slide is moved between the first position and the second position when the cutting blade contacts a pair of stops on the slide. 9. The pneumatically powered pole saw as in claim 7, wherein the first valve releases the source of compressed gas into one side of the piston chamber when a spring biased member of the first valve is depressed into the first valve by the slide and a vent of the second valve allows gas to exit another side of the piston chamber when a spring biased member of the second valve is received into one of a pair of features of the slide and the second valve releases the source of compressed gas into the another side of the piston chamber when a spring biased member of the second valve is depressed into the second valve by the slide and a vent of the first valve allows gas to exit the one side of the piston chamber when a spring biased member of the first valve is received into the other one of the pair of features of the slide. 10. The pneumatically powered pole saw as in claim 1, wherein the source of compressed gas is secured to a wearable harness. 11. The pneumatically powered pole saw as in claim 1, further comprising: a first fluid conduit providing fluid communication between the source of compressed gas and the reciprocating valve and the first fluid conduit has a valve for releasing the compressed gas into the first fluid conduit. 12. The pneumatically powered pole saw as in claim 11, wherein the valve is actuated by a switch disposed on the extendable pole. 13. The pneumatically powered pole saw as in claim 11, further comprising a second fluid conduit for providing fluid communication between the source of compressed gas and the valve, the first fluid conduit being larger than the second fluid conduit and the valve is actuated by a switch proximate to the source of compressed gas, the switch releasing a portion of the compressed gas into the second fluid conduit to actuate the valve. 14. The pneumatically powered pole saw as in claim 1, wherein the cutting blade is positioned at one end of the extendable pole and the source of compressed gas is located at the other end of the extendable pole. 15. The pneumatically powered pole saw as in claim 1, wherein a plurality of teeth of the cutting blade are angled towards the head member. 16. The pneumatically powered pole saw as in claim 1, wherein the cutting blade has a variable thickness. 17. The pneumatically powered pole saw as in claim 16, further comprising a roller for guiding the cutting blade and a stop member is positioned proximate to the roller, the stop member being configured to prevent a branch being cut by the pneumatically powered pole saw from contacting the roller. 18. The pneumatically powered pole saw as in claim 1, further comprising a roller for guiding the cutting blade and a stop member is positioned proximate to the roller, the stop member being configured to prevent a branch being cut by the pneumatically powered pole saw from contacting the roller. 19. The pneumatically powered pole saw as in claim 1, wherein the reciprocating valve is a slide valve coupled to the cutting blade and movement of the cutting blade actuates the slide valve, the slide valve being coupled to the cutting blade and movement of the cutting blade actuates a slide coupled to the cutting blade and a first valve for releasing the source of compressed gas into one side of the piston chamber and a second valve for releasing the source of compressed gas into another side of the piston chamber and the first valve and the second valve are alternately opened and closed by movement of the slide between a first position and a second position. 20. The pneumatically powered pole saw as in claim 1, further comprising a roller mounted to the head member for guiding the cutting blade. 21. The pneumatically powered pole saw as in claim 1, wherein the head member further comprises a stop member configured to define a stop for a limb that is being cut by the pneumatically powered pole saw. 22. A pneumatically powered pole saw, comprising: an extendable pole;a head member secured to the extendable pole;a cutting blade movably mounted to the head member;a piston linked to the cutting blade, the piston being slidably received within a piston chamber of the head member;a reciprocating valve disposed in the head member, the reciprocating valve being configured for movement between a first position and a second position wherein the reciprocating valve releases a portion of a source of compressed gas into the piston chamber on one side of the piston when the reciprocating valve is in the first position causing the cutting blade to move in a first cutting direction towards a limit of travel in the first cutting direction and a first check valve provides fluid communication to the piston chamber on another side of the piston causing the reciprocating valve to move from the first position towards the second position, when the cutting blade reaches the limit of travel in the first direction, the reciprocating valve releases another portion of the source of compressed gas into the piston chamber on the another side of the piston when the reciprocating valve is in the second position causing the cutting blade to move in a second cutting direction opposite to the first cutting direction and towards a limit of travel in the second cutting direction and a second check valve provides fluid communication to the piston chamber on the one side of the piston, the reciprocating valve moving from the second position towards the first position when the cutting blade reaches a limit of travel in the second direction, wherein the reciprocating valve comprises an actuator on either side of the reciprocating valve and a portion of the cutting blade is slidably received on an assembly between a first stop member and a second stop member fixed to the assembly, the assembly being slidably mounted in the head member, wherein contact of the portion of the cutting blade with either the first stop member or the second stop member causes the assembly to move and contact the actuator on either side of the reciprocating valve moving the reciprocating valve between the first position and the second position; anda stop member depending away from a surface of the head member proximate to a path of travel of the cutting blade.