A hydraulic nailing pistol, comprising:
- a frame means including an inlet opening and an outlet opening;
- a magazine means secured to said frame means for housing plural nails;
- guide cylinder means on said frame means;
- a nail driving piston rod means reciprocally mounted in said guide cylinder means for effecting a driving of a nail from said magazine means;
- hydraulically operated means for effecting a reciprocation of said nail driving piston rod means, said hydraulically operated means including:
- (a) a first energy accumulator means adapted to be connected in fluid circuit with a pressurized fluid source through said inlet opening, said first energy accumulator means accummulating energy in response to a fluid connection to said inlet opening;
- (b) passageway means connecting said first energy accumulator means in fluid circuit with said guide cylinder means on a side of said piston rod means remote from said magazine means;
- (c) first valve means intermediate said first energy accumulator means and said guide cylinder means for opening and closing said passageway means;
- (d) second energy accumulator means connected in fluid circuit with said guide cylinder means on a mutually adjacent side of said piston rod means as said magazine means, said second energy accumulator means accumulating energy in response to a movement of said piston rod means toward said magazine means;
- (e) second valve means intermediate said first energy accumulator means and said inlet opening for opening and closing said fluid connection therebetween;
- (f) first means defining a fluid connection between said guide cylinder means at an end thereof between said first valve means and said piston rod means and said outlet opening in said frame means;
- (g) third valve means intermediate said guide cylinder means at the end thereof between said first valve means and said piston rod means, and said outlet opening for opening and closing said fluid connection therebetween, said third valve means also including means for effecting a closing of said first valve means in response to an opening of said third valve means;
- (h) operating slide means operable between conditions effecting an opening and closing of said second and third valve means and a closing and opening, respectively, of said first valve means;
- (i) second means for normally maintaining said operating slide means in a first condition to effect a closing of said first valve means and an opening of said second and third valve means so that said first energy accumulator means will accumulate energy;
- and
- (j) manually operative means for selectively changing the condition of said operating slide means to a second condition to effect a closing of said second and third valve means and an opening of said first valve means so that said piston rod means will be driven by the energy from said first energy accumulator means along the length of said guide cylinder means thereby effecting a driving of a nail from said magazine means and an accumulation of energy in said second energy accumulator means, the energy of said second energy accumulator means being used to effect a return of said piston rod means to a starting position thereof in response to said second means changing said condition of said operating slide means to said first condition thereof.