Impact tool control method and apparatus and impact tool using the same
First Claim
Patent Images
1. A method for determining torque applied to a fastener comprising the steps of:
- applying torque pulses to a fastener;
measuring the values of amplitude and duration of each torque pulse applied to the fastener; and
processing the amplitude and duration of the torque pulses to obtain the total torque applied to the fastener.
3 Assignments
0 Petitions
Accused Products
Abstract
An impact tool control method and apparatus and an impact tool using the same. Pulses of torque applied to a fastener by the impact tool are measured. The duration and magnitude of the torque pulse are subtracted from a torque signal and the resulting difference is integrated over time to obtain a fastener angular velocity signal. The angular velocity signal is integrated over time to obtain a displacement signal which can be converted to a torque signal. The impact tool can be controlled based on the value of the torque signal.
-
Citations
32 Claims
-
1. A method for determining torque applied to a fastener comprising the steps of:
-
applying torque pulses to a fastener;
measuring the values of amplitude and duration of each torque pulse applied to the fastener; and
processing the amplitude and duration of the torque pulses to obtain the total torque applied to the fastener. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. An impact tool comprising:
-
a body;
an output shaft adapted to be coupled to a fastener;
means for applying torque pulses to said output shaft;
a torque transducer coupled to said output shaft;
and means for processing the output of the torque transducer to obtain torque on the fastener. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
-
-
22. A controller for an impact tool comprising:
-
a substraction circuit having an output, a first input and a second input, the first input being configured to accept a value representing calculated torque on a fastener being tightened by the impact tool and the second input being configured to accept a value of torque impulse being applied to the fastener;
a velocity circuit having an output and an input coupled to the output of said substraction circuit and configured to integrate the value of the output of said substraction circuit over time to obtain a value indicating angular velocity of the fastener;
a torque circuit having an output and an input coupled to the output of said velocity circuit and configured to integrate the value of the output of said velocity circuit over time to obtain the value indicating calculated torque on the fastener, the output of said torque circuit being coupled to the first input of said substraction circuit; and
a threshold comparing circuit having an input coupled to the output of the torque circuit and being configured to generate a control signal for controlling the impact tool when a predetermined relationship between the value of the output of the torque circuit and threshold value exists.
-
-
23. A retrofit system for an impact tool of the type comprising a body and an output shaft adapted to be coupled to a fastener, said retrofit system comprising;
-
a shaft extension having a first end and a second end, said first end being adapted to be coupled to the output shaft and said second end being adapted to be coupled to the fastener;
a torque transducer coupled to said shaft extension;
and means for processing the output of the torque transducer to obtain torque on the fastener. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32)
-
Specification