Fastener-driving tool with multiple combustion chambers and usable with fuel canisters of varying lengths

1. A fastener-driving tool comprising:

a first combustion cylinder partially defining a first combustion chamber;

a fuel assembly configured to direct a fuel/air mixture to the first combustion chamber;

a second combustion cylinder attached to the first combustion cylinder and partially defining a second combustion chamber, wherein the second combustion chamber includes a divider that defines a lower chamber portion and an upper chamber portion of the second combustion chamber and is configured to cause an even distribution of the fuel/air mixture flow from the lower chamber portion to the upper chamber portion; and

a combustion chamber sealing assembly comprising a combustion chamber shaft, a first seat disc fixedly attached to the combustion chamber shaft, a second seat disc slidably mounted to the combustion chamber shaft, and a second seat disc biasing element that biases the second seat disc to a biased position,

wherein when the combustion chamber sealing assembly is in an unsealed configuration, the first seat disc is disengaged from a first valve seat and the second seat disc is disengaged from a second valve seat such that the fuel assembly, the first combustion chamber, and the second combustion chamber are in fluid communication,

wherein when the combustion chamber sealing assembly is in a sealed configuration, the first seat disc sealingly engages the first valve seat and the second seat disc sealingly engages the second valve seat such that the fuel assembly, the first combustion chamber, and the second combustion chamber are not in fluid communication, and

wherein when the combustion chamber sealing assembly is in a partially sealed configuration, the first seat disc sealingly engages the first valve seat and the second seat disc is displaced from the biased position and disengaged from a second valve seat such that the fuel assembly and the first combustion chamber are not in fluid communication and the first combustion chamber and the second combustion chamber are in fluid communication.

2. The fastener-driving tool of claim 1 , wherein the first combustion cylinder is a combustion and drive cylinder.

3. The fastener-driving tool of claim 1 , which includes a trigger movable between a rest position and an actuated position.

4. The fastener-driving tool of claim 3 , wherein the combustion chamber sealing assembly is attached to the trigger such that movement of the trigger from the rest position to the actuated position causes the combustion chamber sealing assembly to move from the unsealed configuration to the sealed configuration.

5. The fastener-driving tool of claim 4 , wherein the combustion chamber sealing assembly includes a trigger biasing element that biases the trigger to the rest position and the combustion chamber sealing assembly to the unsealed configuration.

6. The fastener-driving tool of claim 5 , wherein the combustion chamber sealing assembly includes a trigger shaft, wherein the trigger shaft is attached to the combustion chamber shaft and to the trigger.

7. The fastener-driving tool of claim 6 , wherein the combustion chamber sealing assembly includes a linkage that attaches the trigger shaft to the combustion chamber shaft.

8. The fastener-driving tool of claim 1 , wherein the second seat disc is frustoconical.

9. The fastener-driving tool of claim 8 , wherein the second seat disc is formed from a metallic material.

10. The fastener-driving tool of claim 1 , wherein the combustion chamber sealing assembly includes an electrode removably attached to the combustion chamber shaft.

11. The fastener-driving tool of claim 1 , wherein the fuel assembly comprises:

a fuel receiver configured to receive fuel dispensed from a fuel canister removably received in the fuel assembly;

a tube in fluid communication with the fuel receiver; and

a jet pump in fluid communication with the tube and configured to create the fuel/air mixture as the dispensed fuel travels through the jet pump.

12. The fastener-driving tool of claim 11 , wherein the fuel assembly includes an evaporator.

13. The fastener-driving tool of claim 11 , wherein the tube includes a first portion defining a fluid inlet and having a first longitudinal axis, a second portion defining a fluid outlet and having a second longitudinal axis, and a third portion extending between and fluidly connecting the first and second portions and having a third longitudinal axis.

14. The fastener-driving tool of claim 1 , wherein the combustion chamber sealing assembly includes a third seat disc fixedly attached to a combustion chamber shaft.

15. A fastener-driving tool comprising:

a first combustion cylinder partially defining a first combustion chamber;

a fuel assembly configured to direct a fuel/air mixture to the first combustion chamber;

a trigger movable between a rest position and an actuated position;

a second combustion cylinder attached to the first combustion cylinder and partially defining a second combustion chamber; and

a combustion chamber sealing assembly comprising:

a combustion chamber shaft,

a first seat disc fixedly attached to the combustion chamber shaft,

a second seat disc slidably mounted to the combustion chamber shaft,

a second seat disc biasing element that biases the second seat disc to a biased position,

a trigger shaft connected to the trigger at a first end of the trigger shaft, and

a linkage fixedly attached to a second end of the trigger shaft such that the linkage connects the trigger shaft to the combustion chamber shaft,

wherein the combustion chamber sealing assembly is attached to the trigger shaft such that movement of the trigger from the rest position to the actuated position causes the combustion chamber sealing assembly to move from an unsealed configuration to a sealed configuration,

wherein in the unsealed configuration, the first seat disc is disengaged from a first valve seat and the second seat disc is disengaged from a second valve seat such that the fuel assembly, the first combustion chamber, and the second combustion chamber are in fluid communication,

wherein when the combustion chamber sealing assembly is in a sealed configuration, the first seat disc sealingly engages the first valve seat and the second seat disc sealingly engages the second valve seat such that the fuel assembly, the first combustion chamber, and the second combustion chamber are not in fluid communication, and

wherein when the combustion chamber sealing assembly is in a partially sealed configuration, the first seat disc sealingly engages the first valve seat and the second seat disc is displaced from the biased position and disengaged from a second valve seat such that the fuel assembly and the first combustion chamber are not in fluid communication and the first combustion chamber and the second combustion chamber are in fluid communication.

16. The fastener-driving tool of claim 15 , wherein the combustion chamber sealing assembly has an upside down U-shaped configuration fixedly connecting the linkage to the combustion chamber shaft and the trigger shaft.

17. The fastener-driving tool of claim 15 , wherein the combustion chamber sealing assembly includes a trigger biasing element that biases the trigger to the rest position and the combustion chamber sealing assembly to the unsealed configuration.