Author: claimsbot

1. A lockable caster comprising:
a mounting member adapted to be connected to a load to be supported by the caster;
a yoke pivotally connected to the mounting member for relative pivotal movement about a swivel axis, the yoke comprising two depending legs interconnected by an upper bight portion;
a wheel mounted between the legs of the yoke for rotation about a running axis;
a locking structure between the legs of the yoke adjacent the bight portion and fixed relative to the mounting member, the locking structure comprising recesses spaced so as to at least partially surround the swivel axis;
a total lock mechanism carried by the yoke, comprising a movable brake member adapted to engage the wheel to lock it against rotation, and a movable total lock tooth configured to engage any of a plurality of the recesses to lock the yoke against pivotal movement about the swivel axis in any of a plurality of total lock positions; and
a directional lock mechanism carried by the yoke and comprising a movable directional lock tooth adapted to engage at least one of the recesses to lock the yoke against pivotal movement about the swivel axis in at least one directional lock position while allowing the wheel to rotate, the number of directional lock positions being fewer than the number of total lock positions.
2. A lockable caster according to claim 1, wherein all of the recesses are coplanar.
3. A lockable caster according to claim 2, wherein all of the recesses lie along a circle centered on the swivel axis.
4. A lockable caster according to claim 3, wherein:
the directional lock tooth is wider than the total lock tooth;
at least one of the recesses is a directional lock recess having a width sized to accommodate the directional lock tooth; and
the other recesses are equal-width total lock recesses that are equally spaced on either side of the at least one directional lock recess and are sized to accommodate the total lock tooth but not the directional lock tooth.
5. A lockable caster according to claim 4, wherein the total lock tooth comprises a plurality of tines spaced such that each tine can engage a total lock recess, the overall width of the plurality of tines being equal to the width of the directional lock tooth so that the total lock tooth can engage a directional lock recess.
6. A lockable caster according to claim 5, wherein the total lock tooth comprises two tines.
7. A lockable caster according to claim 5, comprising two diametrically opposed directional lock recesses.
8. A lockable caster according to claim 1, wherein the locking structure comprises a lower ball retainer of a pivot bearing assembly, and a plurality of the recesses are located at the periphery of the lower ball retainer.
9. A lockable caster according to claim 1, wherein the number of recesses engageable by the directional lock tooth is fewer than the number of recesses engageable by the total lock tooth.
10. A lockable caster according to claim 1, wherein the total lock mechanism comprises a total lock lever pivoted intermediate its ends to the yoke, and the brake member and the total lock tooth are at opposite ends of the total lock lever.
11. A lockable caster according to claim 10, wherein the directional lock mechanism comprises a directional lock lever pivoted intermediate its ends to the yoke, and the directional lock tooth is at one end of the directional lock lever.
12. A lockable caster according to claim 11, wherein the total lock lever and the directional lock lever are arranged side-by-side.
13. A lockable caster according to claim 12, wherein the wheel has a medial plane perpendicular to the running axis, and the brake member is canted toward the medial plane so as to be engageable with the outer circumference of the wheel.
14. A lockable caster according to claim 12, wherein the total lock lever and the directional lock lever are pivoted to the yoke about a common pivot axis.
15. A lockable caster according to claim 14, wherein each of the lock mechanisms is spring-biased away from a locked state and comprises an expanding over-center toggle mechanism pivoted to the yoke for moving the lock mechanism against the spring bias into a locked state.
16. A lockable caster according to claim 15, wherein each toggle mechanism comprises a four-bar linkage, one link of the toggle mechanism being pivoted to its respective lock lever remote from the toothed end thereof and having an extension forming an operating pedal for moving the lock mechanism into a locked state.
17. A lockable caster according to claim 16, wherein the operating pedals of the toggle mechanisms are arranged side-by-side.
18. A lockable caster according to claim 17, further comprising a common release pedal pivoted to the yoke above the operating pedals and linked to each toggle mechanism for releasing either or both of the lock mechanisms from a locked state.
19. A lockable caster comprising:
a mounting member adapted to be connected to a load to be supported by the caster;
a yoke pivotally connected to the mounting member for relative pivotal movement about a swivel axis, the yoke comprising two depending legs interconnected by an upper bight portion;
a wheel mounted between the legs of the yoke for rotation about a running axis;
a locking structure between the legs of the yoke adjacent the bight portion and fixed relative to the mounting member, the locking structure comprising coplanar recesses spaced along a circle centered on the swivel axis, at least one of the recesses being a directional lock recess, and a greater number of other recesses being total lock recesses, which are configured differently from the at least one directional lock recess;
a total lock mechanism carried by the yoke, comprising a movable brake member configured to engage the wheel to lock it against rotation, and a movable total lock tooth configured to engage any of the total lock recesses and any of the directional lock recesses to lock the yoke against pivotal movement about the swivel axis in any of a plurality of total lock positions; and
a directional lock mechanism carried by the yoke, comprising a movable directional lock tooth configured to engage only the directional lock recesses to lock the yoke against pivotal movement about the swivel axis in at least one directional lock position while allowing the wheel to rotate.
20. A lockable caster according to claim 19, wherein:
the total lock mechanism comprises a total lock lever pivoted intermediate its ends to the yoke, and the brake member and the total lock tooth are at opposite ends of the total lock lever, and the directional lock mechanism comprises a directional lock lever pivoted intermediate its ends to the yoke, and the directional lock tooth is at one end of the directional lock lever.
21. A lockable caster according to claim 20, wherein the total lock lever and the directional lock lever are pivoted to the yoke about a common pivot axis and are arranged side-by-side with their toothed ends adjacent each other.
22. A lockable caster according to claim 21, wherein the wheel has a medial plane perpendicular to the running axis, and the brake member is canted toward the medial plane so as to be engageable with the outer circumference of the wheel.

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. A method of presenting a book to a user for reading comprising:
a) storing the content of a book as separate pages in a computerized database;
b) presenting the separate pages to the user through a user interface created by a web server operating on a server computer;
c) tracking user interaction with the user interface, specifically tracking page clicks requesting a new page in the book; and
d) analyzing at the server computer the page clicks to verify that a user has read the book.
2. The method of claim 1, wherein the step of analyzing page clicks comprises determining that the user has viewed a certain number of pages in the book.
3. The method of claim 2, wherein the certain number is determined with reference to the total number of pages in the book.
4. The method of claim 3, wherein the certain number is the same as the total number of pages in the book.
5. The method of claim 3, wherein the certain number is at least ninety-five percent of the total number of pages in the book.
6. The method of claim 2, wherein the step of analyzing page clicks further comprises analyzing the time spent by the user on each page.
7. The method of claim 6, wherein the step of analyzing the time spent on each page further comprises comparing page click records in the computerized database.
8. The method of claim 7, wherein each page click record identifies a particular user, a particular book, a particular page in the particular book, and contains a time stamp.
9. The method of claim 8, wherein the step of comparing page click records comprises comparing a first time stamp on a first page click record with a second time stamp on a second page click record, wherein the second page click record is the next page click record chronologically for the particular user and the particular book.
10. The method of claim 1, wherein the step of analyzing page clicks further comprises analyzing the time spent by the user on each page.
11. The method of claim 6, wherein the step of analyzing the time spent on each page further comprises comparing page click records in the computerized database.
12. The method of claim 7, wherein each page click record identifies a particular user, a particular book, a particular page in the particular book, and contains a time stamp.
13. The method of claim 8, wherein the step of comparing page click records comprises comparing a first time stamp on a first page click record with a second time stamp on a second page click record, wherein the second page click record is the next page click record chronologically for the particular user and the particular book.
14. A method of presenting a book to a user for reading comprising:
a) storing the content of a book as separate pages in a computerized database;
b) presenting the separate pages to the user through a user interface created by a web server operating on a server computer;
c) tracking user interaction with the user interface, specifically tracking page clicks requesting a new page in the book; and
d) analyzing the page clicks to determine that a user has ceased reading the book.
15. A system for presenting a book to a user for reading comprising:
a) a processor for processing software instructions;
b) a tangible, non-transitory memory containing software instructions;
c) a database containing entities for users and books,
wherein book records include individual page records;
wherein the content of the book is stored in the individual page records; and
wherein the software tracks user interaction with the page records, with the software recording in page click records each request of a user to access a new page from the book, the page click records including an identifier for the user, the book, the page, and a time.

What is claimed is:

1. An overlay mark for determining the relative position between two or more successive layers of a substrate or between two or more separately generated patterns on a single layer of a substrate, the overlay mark comprising:
a plurality of working zones used to calculate alignment between a first and a second layer of the substrate or between a first and a second pattern on a single layer of the substrate, each of the working zones being positioned within the perimeter of the mark, each of the working zones representing a different area of the mark, the working zones being configured to substantially fill the perimeter of the mark such that the combined area of the working zones is substantially equal to the total area of the mark.
2. The overlay mark as recited in claim 1 wherein the perimeter of the mark corresponds to the optical perimeter of the field of view of the metrology tool used to image the overlay mark, the field of view defining the area available for capturing an image via the metrology tool.
3. The overlay mark as recited in claim 1 wherein the working zones are configured to diminish the impact of non-uniformities across the mark on tool and wafer induced shifts.
4. The overlay mark as recited in claim 1 further including a periodic structure positioned within each of the working zones, each of the periodic structures including a plurality of coarsely segmented elements.
5. The overlay mark as recited in claim 4 wherein the pitch, period and duty cycle of the coarsely segmented elements is configured to balance the resolution of the metrology used to image the overlay mark and the robustness of the process used to form the layers.
6. The overlay mark as recited in claim 4 wherein the coarsely segmented elements are parallel lines.
7. The overlay mark as recited in claim 4 wherein the relative shift between the first and second layers of the wafer is determined by comparing the relative positions of periodic structures on different layers.
8. The overlay mark as recited in claim 4 wherein the plurality of coarsely segmented elements are formed by a plurality of finely segmented elements.
9. The overlay mark as recited in claim 8 wherein finely segmented elements are configured to provide shift information that more closely matches the relative shift between patterns of an integrated circuit formed on each of the two layers of the substrate.
10. The overlay mark as recited in claim 1 wherein the working zones are separated by exclusion zones.
11. The overlay mark as recited in claim 1 wherein the working zones are configured to represent one of a first layer or first pattern or a second layer or second pattern.
12. The overlay mark as recited in claim 11 wherein the working zones represent an equal number of first layers or patterns and second layers or patterns.

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 aircraft slat assembly comprising a first slat and a second slat positioned adjacent thereto and aligned therewith, the first and second slats being moveable between extended and retracted positions in which the first and second slats remain aligned,
wherein the slats are connected by a joint, the joint prevents the slats becoming misaligned and the joint being arranged to transfer the shear load generated as the slats are being urged into a misaligned configuration, from one slat to the other slat, such that the shear load may be detected or otherwise used to identify the existence of a condition which could have lead to excess misalignment, before such misalignment actually occurs.
2. An assembly according to claim 1, wherein the slat assembly comprises an actuator system arranged to drive the slats between the extended and retracted positions.
3. An assembly according to claim 2, wherein the actuator system comprises a common drive means arranged to drive both the slats between the extended and retracted positions.
4. An assembly according to claim 2 further comprising a protector system, wherein the protector system is arranged to trip at least part of the actuator system in the event of an excessive load occurring in the actuator system.
5. An assembly according to claim 4 wherein the protector system is arranged to trip the actuator system when the magnitude of the shear load transferred from one slat to the other slat exceeds a threshold magnitude.
6. An assembly according to claim 1 wherein the joint comprises a rigid coupling between the slats, which substantially resists deformation under the shear load.
7. An assembly according to claim 1, wherein the joint is arranged to allow relative movement between the slats in a direction along the longitudinal axis of the slats.
8. An assembly according to claim 1, wherein the joint is arranged to allow relative rotation between the slats.
9. An assembly according to claim 1, wherein each slat comprises a first region proximal to the joint, and a second region distal from the joint, the first region being stiffer than the second region such that deformation of the slat in the first region, under the influence of the shear load, is inhibited.
10. An aircraft slat assembly comprising a first slat and a second slat positioned adjacent thereto and aligned therewith, the first and second slats being moveable between extended and retracted positions in which the first and second slats remain aligned,
wherein the slats are connected by a joint, the joint permitting relative movement between the slats in at least some directions, but the joint prevents relative movement between the slats in the direction of extensionretraction of the slats, the joint thereby prevents the slats becoming misaligned.