1. A method of extracting a nail from a surface comprising the steps of:
positioning a hammer adjacent to the nail in a manner that a striking surface of the hammer-that defines a front of the hammer, contacts the surface from which the nail is to be extracted;
engaging the nail with a first frontal extractor that is positioned toward the front of the hammer proximate to the striking surface of the hammer;
rotating a handle of the hammer about the striking surface to partially extract the nail from the surface;
disengaging the nail from the first frontal extractor;
engaging the nail with a second frontal extractor that is positioned toward the front of the hammer between the first frontal extractor and the handle of the hammer; and
rotating the handle of the hammer about the striking surface to further extract the nail from the surface.
2. The method of claim 1, wherein said steps of engaging the nail with the second frontal extractor and rotating the handle of the hammer about the striking surface to further extract the nail from the surface.
3. The method of claim 1, further including the steps of:
disengaging the nail from the second frontal extractor;
engaging the nail with a third frontal extractor that is positioned toward the front of the hammer between the second frontal extractor and the handle of the hammer; and
rotating handle of the hammer about the striking surface to further extract the nail from the surface.
4. A method of extracting a nail from a surface comprising the steps of:
providing a hammer having a striking head with a striking surface, a handle, a first frontal extractor, and a second frontal extractor;
engaging the nail with the first frontal extractor;
rotating handle of the hammer about the striking surface to at least partially extract the nail;
disengaging the nail from the first frontal extractor;
engaging the nail with the second frontal extractor; and
rotating handle of the hammer about the striking surface to further extract the nail from the surface.
5. The method of claim 4, wherein the hammer further comprises an interface section, the first and second frontal extractors being provided on the interface section.
6. The method of claim 5, wherein the interface section includes a groove that extends through the first and second frontal extractors.
7. The method of claim 5, wherein the interface section diagonally spans between the underside of the striking head and the handle.
8. The method of claim 5, wherein the interface section is integrally formed together with the striking head.
9. The method of claim 5, wherein the interface section includes at least one slot that forms at least one of the first and second frontal extractors.
10. The method of claim 9, wherein the at least one slot has an angular shape so that width of the slot decreases toward the interface section.
11. The method of claim 9, wherein the at least one slot is sized to allow a head of a nail to be supported therein so that the nail is cantilevered substantially perpendicular relative to the striking surface.
12. The method of claim 9, wherein the at least one slot is dimensioned approximately between 116 to 18 inch in width.
13. The method of claim 9, wherein the at least one slot is tapered so that width of the slot decreases toward the interface section.
14. The method of claim 4, wherein at least one of the first frontal extractor and the second frontal extractor is cantilevered from the striking head.
15. The method of claim 4, wherein the first frontal extractor is cantilevered substantially parallel to the handle, and is spaced approximately 1 58 inches from the handle.
16. The method of claim 4, wherein the second frontal extractor is cantilevered between the handle and the first frontal extractor, and is spaced approximately 1 14 inches from the handle.
17. The method of claim 4, wherein the first frontal extractor is longer than the second frontal extractor.
18. The method of claim 4, wherein at least one of the first and second frontal extractors is magnetized to allow a nail to be supported therein so that the nail is cantilevered substantially perpendicular relative to the striking surface.
19. The method of claim 4, wherein the first frontal extractor and the second frontal extractor are integrally formed with the striking head.
20. The method of claim 4, wherein the hammer includes a third frontal extractor, and further including engaging the nail with the third frontal extractor, and rotating handle of the hammer about the striking surface to further extract the nail from the surface.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An equalizer comprising:
a controllable equalization circuit connected to receive a data waveform, and to receive a control signal, and arranged to apply an equalization to the data waveform in accordance with the control signal and provide a resultant waveform,
a data sampler connected to receive the resultant waveform from the equalization circuit and to provide data sampled from the resultant waveform,
an earlylate detector connected to receive the resultant waveform, arranged to examine the resultant waveform to determine whether transitions between logic levels fall earlier or later than expected and to provide indications of that, and
a control circuit connected to receive the data samples and the earlylate indications from the earlylate detector, arranged to determine from those signals whether the equalization needs to be adjusted, and connected to provide accordingly the control signal to the equalization circuit,
characterized in that the control circuit is arranged to generate the control signal in response to the occurrence of particular patterns of data samples received and from information as to whether a transition between two consecutive samples of each pattern is early or late according to the following rules:
providing a control signal indicating an increase in the equalization to be provided by the equalization circuit if both (i) the samples and earlylate indication for a relatively long run of a particular logic level in the data followed by a transition and those for a relatively short run of a particular logic level followed by a transition both indicate that the equalizer is providing underequalization and (ii) no pattern to which the control circuit is responsive and its corresponding earlylate indication indicates that the equalizer is providing overequalization, and
providing a control signal indicating a reduction in the equalization to be provided by the equalization circuit if both (i) the samples and earlylate indication for a relatively long run of a particular logic level in the data followed by a transition and those for a relatively short run of a particular logic level followed by a transition both indicate that the equalizer is providing overequalization and (ii) no pattern to which the control circuit is responsive and its corresponding earlylate indication indicates that the equalizer is providing underequalization.
2. An equalizer as claimed in claim 1, wherein the control circuit comprises one or more code recognizers connected to detect when a particular pattern of samples has been received.
3. An equalizer as claimed in claim 2, wherein the code recognizer, or recognizers, is arranged to recognize a particular combination of:
(i) a particular pattern of received samples, and
(ii) one of either the transition between two samples of the pattern being early or late, and to output a signal indicating that that combination has been recognized.
4. An equalizer as claimed in claim 3, comprising a discriminator connected to receive the outputs of a plurality of code recognizers and arranged, in response thereto, to provide an overall signal indicating how the equalization circuit is to be adjusted.
5. An equalizer as in claim 1, so arranged that the control circuit applies its rules to data samples received within a particular period of time, the rules being reapplied for later particular periods of time.
6. An equalizer as in claim 1, wherein the controllable equalization circuit comprises a filter having gain that is adjustable in a particular range of frequencies, which is connected to be so adjusted by the control signal from the control circuit.
7. An equalizer as claimed in claim 6, wherein the filter comprises an adjustable resistance that is connected to be adjusted by the control signal from the control circuit.
8. An equalizer as in claim 1, comprising a second data sampler connected to receive the resultant waveform and to provide samples thereof at the expected points of transitions between logic levels in the waveform, wherein the earlylate detector is connected to receive those samples and also the resultant waveform in sampled form from the first data sampler, and is arranged to provide its earlylate indications based on the sampled from the two data samplers.
9. An equalizer as in claim 8, comprising an error detect unit responsive to the data samples and connected to the control circuit to signal the occurrence of errors or the rate of those errors, the control circuit being arranged to vary the equalization provided in a particular manner until the errors meet a criterion, the control circuit thereafter being responsive to the data samples and the earlylate information to control the controllable equalization circuit.
10. A system comprising:
a source of a data waveform,
an equalizer as claimed in any preceding claim, and
a data transmission line connected to deliver the data waveform to the controllable equalization circuit, of the equalizer, as its input.
11. A system as claimed in claim 10, wherein the controllable equalization circuit comprises a filter having a high pass characteristic.
12. A system as claimed in claim 11, wherein the high pass filter characteristic has a pass band including the frequency of half the data rate of the data waveform.
13. A system as claimed in claim 11, wherein the position of the pass band in frequency is programmable.
14. A method of equalization, comprising the steps of:
receiving a data waveform;
applying an equalization to the data waveform to provide a resultant waveform;
examining the resultant waveform to determine whether transitions between logic levels therein fall earlier or later than expected and to provide indications of that;
sampling the resultant data waveform;
in response to the samples and the earlylate indications adjusting the equalization applied,
characterized in that the adjusting of the equalization is performed as follows:
taking into account the occurrence of any of a plurality of particular patterns in the data samples and whether a transition between two consecutive samples of each pattern is early or late,
increasing the equalization if both (i) the samples and earlylate indications for a relatively long run of a particular logic level in the data followed by a transition and those for a relatively short run of a particular logic level followed by a transition both indicate that there is underequalization and (ii) no occurrence of a pattern of the plurality and its corresponding earlylate indication indicates that there is overequalization, and
reducing the equalization if both (i) the samples and earlylate indications for a relatively long run of a particular logic level in the data followed by a transition and those for a relatively short run of a particular logic level followed by a transition both indicate that there is providing overequalization and (ii) no occurrence of a pattern of the plurality and its corresponding earlylate indication indicates that there is underequalization.
15. A method of equalization as claimed in claim 14, wherein the equalization is adjusted by adjusting the gain applied to the data waveform in a particular range of frequencies.
16. A method as claimed in claim 14, comprising detecting errors in the data samples, and varying the equalization provided in a particular manner until the errors meet a criterion, and thereafter adjusting the equalization applied in response to the data samples and the earlylate information.
17. A method of equalization as in claim 14, wherein the equalization applied has a high pass characteristic.
18. A method of equalization as claimed in claim 17, wherein the high pass characteristic has a pass band including the frequency of half the data rate of the data waveform.
19. A method as claimed in claim 14, wherein the examining the resultant waveform to determine whether transitions between logic levels therein fall earlier or later than expected at the expected points of transitions between logic levels in the waveform comprises: determining from two consecutive samples of the data waveform and the sample taken at the expected point of transition between them whether the transition is earlier or later than expected.
20. A method as in claim 14, wherein the criteria (i) and (ii) for the increasing or reducing of the equalization are applied to data samples received within a particular period of time, the criteria being re-evaluated for later particular periods of time.