Exercise device with a safety lock

1. An exercise device comprising:

a frame supporting a track and a load rack;

a lock frame supporting a guide member, said track received by said guide member;

a pawl shaft articulated by a handle and said pawl shaft received by said lock frame;

a first pawl mounted to said pawl shaft, thereby enabling selective engagement and disengagement of said first pawl with said load rack by way of said handle;

a second pawl movably mounted to said lock frame; and

a bias mechanism connecting said first pawl to said second pawl.

2. The exercise device as in claim 1 , wherein said load rack is a notched rack.

3. The exercise device as in claim 2 , wherein said notched rack is comprised of a plurality of saw-toothed notches.

4. The exercise device as in claim 1 , wherein said track is a track selected from a group consisting of a shaft a tube.

5. The exercise device as in claim 1 , wherein said guide member is a device selected from the group consisting of a linear bearing, a bushing and a rolling element.

6. The exercise device as in claim 5 , wherein said rolling element includes a wheel, ball bearing and a carriage roller.

7. The exercise device as in claim 1 , wherein said handle is a substantially longitudinal bar substantially collinear with said pawl shaft.

8. The exercise device as in claim 1 , wherein said pawl shaft is articulated by said handle by way of a push bar.

9. The exercise device as in claim 1 , wherein said bias mechanism is comprised of a spring.

10. The exercise device as in claim 9 , wherein said spring is an extension spring.

11. The exercise device as in claim 1 , wherein said load rack is movably mounted to said frame.

12. The exercise device as in claim 11 , wherein said exercise device further includes a base spring at least partially supporting said rack on said frame.

13. The exercise device as in claim 12 , wherein said base spring is comprised of a compression spring.

14. The exercise device as in claim 13 , wherein said compression spring is manufactured from a material consisting of plastic, metal, natural rubber and synthetic rubber.

15. The exercise device as in claim 13 , wherein said base spring is a polyurethane bumper pad.

16. The exercise device as in claim 1 , wherein said second pawl is counterbalanced such that, in a relaxed state, said second pawl is engaged with said rack.

17. The exercise device as in claim 1 , wherein said bias member holds said second pawl in a position disengaged from said rack.

18. The exercise device as in claim 1 , further comprising a bumper stop releasably mounted to said rack.

19. The exercise device as in claim 18 , wherein said bumper stop is movably mounted to said rack along a portion of the length of said rack.

20. The exercise device as in claim 1 , wherein said lock frame includes a tension member connected to a counterweight.

21. The exercise device as in claim 1 , said second pawl further comprising in combination:

a counterbalance plate; and

a pawl portion, the combination pivotally mounted to said lock frame.

22. The exercise device as in claim 1 , said lock frame further comprising an upper stop plate enabling a movement boundary of said first pawl in an unlocked state.

23. The exercise device including a load rack and a substantially linear track received by a guide member which is supported by a lock frame, the exercise device including a safety locking device comprising:

a pawl shaft articulated by a handle and said pawl shaft received by said lock frame;

a first pawl mounted to said pawl shaft, thereby enabling selective engagement and disengagement of said first pawl with said load rack by way of said handle;

a second pawl movably mounted to said lock frame; and

a bias mechanism connecting said first pawl to said second pawl.

24. The exercise device as in claim 23 , wherein said load rack is a notched rack.

25. The exercise device as in claim 24 , wherein said notched rack is comprised of a plurality of saw-toothed notches.

26. The exercise device as in claim 23 , wherein said track is a track selected from a group consisting of a shaft a tube.

27. The exercise device as in claim 23 , wherein said guide member is a device selected from the group consisting of a linear bearing, a bushing and a rolling element.

28. The exercise device as in claim 27 , wherein said rolling element includes a wheel, ball bearing and a carriage roller.

29. The exercise device as in claim 23 , wherein said handle is a substantially longitudinal bar substantially collinear with said pawl shaft.

30. The exercise device as in claim 23 , wherein said pawl shaft is articulated by said handle by way of a push bar.

31. The exercise device as in claim 23 , wherein said bias mechanism is comprised of a spring.

32. The exercise device as in claim 31 , wherein said spring is an extension spring.

33. The exercise device as in claim 23 , wherein said load rack is movably mounted to said frame.

34. The exercise device as in claim 33 , wherein said exercise device further includes a base spring at least partially supporting said rack on said frame.

35. The exercise device as in claim 34 , wherein said base spring is comprised of a compression spring.

36. The exercise device as in claim 35 , wherein said compression spring is manufactured from a material consisting of plastic, metal, natural rubber and synthetic rubber.

37. The exercise device as in claim 35 , wherein said base spring is a polyurethane bumper pad.

38. The exercise device as in claim 23 , wherein said second pawl is counterbalanced such that, in a relaxed state, said second pawl is engaged with said rack.

39. The exercise device as in claim 23 , wherein said bias member holds said second pawl in a position disengaged from said rack.

40. The exercise device as in claim 23 , further comprising a bumper stop releasably mounted to said rack.

41. The exercise device as in claim 40 , wherein said bumper stop is movably mounted to said rack along a portion of the length of said rack.

42. The exercise device as in claim 23 , wherein said lock frame includes a tension member connected to a counterweight.

43. The exercise device as in claim 23 , further comprising a weight collar adapted to receive weight plates, the collar mounted to said lock frame.

44. The exercise device as in claim 23 , the second pawl further comprising in combination:

a counterbalance plate; and

a pawl portion, the combination pivotally mounted to said lock frame.

45. The exercise device as in claim 23 , further comprising an upper stop plate mounted to said lock frame for enabling a movement boundary of said first pawl in an unlocked state.

46. A method of exercise for use with exercise device including a load rack and a substantially linear track received by a guide member which is supported by a lock frame, the exercise device including a safety locking device including a pawl shaft articulated by a handle and said pawl shaft received by said lock frame; a first pawl mounted to said pawl shaft, thereby enabling selective engagement and disengagement of said first pawl with said load rack by way of said handle; a second pawl movably mounted to said lock frame; and a bias mechanism connecting said first pawl to said second pawl, the method of exercise including the steps of:

grasping said handle by a user;

articulating said handle to disengage said first pawl from said rack; and

moving said lock frame thereby exercising the muscles of the user.

47. The method of exercise as in claim 46 , further including the step of:

adding a weight plate to said lock frame.

48. A method of using a safety lock on an exercise device of the type including a load rack and a substantially linear track received by a guide member which is supported by a lock frame, the exercise device including a safety locking device including a pawl shaft articulated by a handle and said pawl shaft received by said lock frame; a first pawl mounted to said pawl shaft, thereby enabling selective engagement and disengagement of said first pawl with said load rack by way of said handle; a second pawl movably mounted to said lock frame; and a bias mechanism connecting said first pawl to said second pawl, the method including:

providing said bias member to become disconnected from either of said first pawl or said second pawl; and

allowing said second pawl to engage with said rack, thereby limiting movement of said lock frame in at least one direction.