in it, you see that when the pendulum pushes the arm on the right (which has already been reset), that arm releases the scapewheel, which then resets the arm on the left.
really, the only flaw in your design is that it doesn't allow for an air fly; an air fly slows the rotation of the scapewheel, but to do so in your design would result in the pendulum contacting the arm before it can fully reset.
I see NO impulse !!! The impulse arns are lifted COMPLETELY by the pendulum ! And the opposite arm is NOT lifted at all when the escapment wheel rotates (for example, wnen the pendulum is at left and GENTLY lifts the left impulse arm to release the escapement wheel, the escapement wheel should lift the RIGHT impulse arm).
And also, the re is no fan or energy dissipating device. This such device is needed to prevent any false escapement.
There is definitely impulse - the pendulum hits the arm and unlocks it, the train then drives the arm up faster than the pendulum. The impulse is then because the arm is higher than the pendulum when it regains contact. Kinetic Energy is then transferred to the pendulum. There is no need for a fan on this device - the locking mechanism ensures there is no possibility of runaway.
However, I appreciate now this is not a classic gravity escapement.
I think something is wrong: the gravity arms are lifted AFTER they are unlocked by the pendulum. They shoud be in the high energy position BEFORE they are touched by the pendulum.
You are right. The initial contact from the pendulum drives the unlock then the drive from the train raises the arm. Overall more energy is imparted to the pendulum than is lost so ... err ... it works.
@pcstru No, not as far as I know. See, e.g. Grimthorpe's 4 legged gravity escapement by 'horolophile'. That it works is not a guarantee that the thought behind it (constant impulstransfer, not directly by the geartrain) is realized.
I referenced a couple of examples by googling "Gravity Escapement" and worked from there.
I was lucky enough to get a copy of "Practical Clock Escapements" by Laurie Penman (ISBN 0 9523270 4 X) for christmas, which has a whole chapter on gravity escapements. That would have been a big help at the time!
have a look at this video: watch?v=8qEEGDBl2vw
in it, you see that when the pendulum pushes the arm on the right (which has already been reset), that arm releases the scapewheel, which then resets the arm on the left.
really, the only flaw in your design is that it doesn't allow for an air fly; an air fly slows the rotation of the scapewheel, but to do so in your design would result in the pendulum contacting the arm before it can fully reset.
KEvron
KEvronista 7 months ago
I see NO impulse !!! The impulse arns are lifted COMPLETELY by the pendulum ! And the opposite arm is NOT lifted at all when the escapment wheel rotates (for example, wnen the pendulum is at left and GENTLY lifts the left impulse arm to release the escapement wheel, the escapement wheel should lift the RIGHT impulse arm).
And also, the re is no fan or energy dissipating device. This such device is needed to prevent any false escapement.
ve2zzz 1 year ago
@ve2zzz
There is definitely impulse - the pendulum hits the arm and unlocks it, the train then drives the arm up faster than the pendulum. The impulse is then because the arm is higher than the pendulum when it regains contact. Kinetic Energy is then transferred to the pendulum. There is no need for a fan on this device - the locking mechanism ensures there is no possibility of runaway.
However, I appreciate now this is not a classic gravity escapement.
pcstru 1 year ago
I think something is wrong: the gravity arms are lifted AFTER they are unlocked by the pendulum. They shoud be in the high energy position BEFORE they are touched by the pendulum.
BenVanDeWaal 2 years ago
You are right. The initial contact from the pendulum drives the unlock then the drive from the train raises the arm. Overall more energy is imparted to the pendulum than is lost so ... err ... it works.
Is this not how it is supposed to work?
pcstru 2 years ago
@pcstru No, not as far as I know. See, e.g. Grimthorpe's 4 legged gravity escapement by 'horolophile'. That it works is not a guarantee that the thought behind it (constant impulstransfer, not directly by the geartrain) is realized.
BenVanDeWaal 2 years ago
If I remember right, that's Denison's double three legged gravity escapment he invented in the early 1850's.
GrnArrow092 2 years ago
nice Video
The very famous Big Ben Towerclock
got this Escapement.
philclock 4 years ago
I referenced a couple of examples by googling "Gravity Escapement" and worked from there.
I was lucky enough to get a copy of "Practical Clock Escapements" by Laurie Penman (ISBN 0 9523270 4 X) for christmas, which has a whole chapter on gravity escapements. That would have been a big help at the time!
pcstru 4 years ago
I would like to make a gravity escapement in brass. Do you know of any plans available
john92037 4 years ago