1. A folding wheel chair having a pair of side frames with a pair of wheels, a pair of cross links connecting said side frames each other, and a seat which is foldable by changing the distance between the both side frames, comprising:
said seat consists of a front right section, a front left section, a rear right section and a rear left section,
whereby said front right and left sections are connected swingably to front edges of said rear right and left sections respectively via a first transverse axis at the rear edges, and are connected swingably to the front portions of said cross links respectively via a second transverse axis,
said front right and rear right sections are connected swingably to the right edges of said front left and rear left sections respectively via the first longitudinal axis at the left edges,
said rear right and left sections are connected to said cross links respectively via an elastic member,
said seat takes the substantially horizontal seating state when the load to said seat is greater than the repellent force of the elastic member,
said seat is brought in the stand-up state when said rear right and left sections are lifted up and said front right and left sections are inclined forward when the load to said seat is less than the repellent force of said elastic member.
2. A folding wheel chair as set forth in claim 1, wherein said front right and left sections can swing to said rear right and left sections via said first traverse axis in a range between the same flat state and the reverse-V folded state, and said front right and rear right sections can swing to said front left and rear left sections via said first longitudinal axis in the range between the same flat state and the reverse-V folded state.
3. A folding wheel chair as set forth in claim 1, wherein the rear right portion of said rear right section and the rear left portion of said rear left section are connected respectively to the respective ends of right and left link rods via the third traverse axis, and the other ends of said right and left link rods are connected respectively to said cross links via the fourth traverse axis.
4. A folding foldable wheel as set forth in claim 3, wherein the longitudinal lengths of said right and left link rods are equal to the same of said front right and left sections, and said rear right and left sections are substantially horizontal in the stand-up state.
5. A folding wheel as set forth in claim 3, wherein the other ends of said right and left link rods are connected respectively to said cross links via second and third longitudinal axes.
6. A folding wheel chair as set forth in claim 3, wherein the right end of said rear right section and the left end of said rear left section are connected respectively to said cross links via said second and third longitudinal axes.
7. A folding wheel chair as set forth in claim 1, wherein the lower end of said elastic member is connected to the crossing point of said cross links via the fifth traverse axis.
8. A folding wheel chair as set forth in claim 7, wherein said rear right and left sections are connected respectively to the upper end of said elastic member via a linkage, whereby the distance between the upper end of said elastic member and the crossing point is substantially constant.
9. A folding wheel chair as set forth in claim 7, wherein said linkage have right and left link members, which are connected each other at the lower ends via said fourth longitudinal axis, and connected respectively to said rear right and left sections at the upper ends.
10. A folding wheel chair as set forth in claim 7, wherein said fifth and sixth longitudinal axes are arranged at medium level between said first and fourth longitudinal axes in the folded state.
11. A folding wheel chair as set forth in claim 7, wherein the lengths of said right and left link members are substantially half of the length which is obtained by subtracting the length between said fourth longitudinal axis and the crossing point of said cross links from the sum of length between the first longitudinal axis and the second and third longitudinal axes and the length between the crossing point of said cross links and the second and third longitudinal axes.
12. A folding wheel chair as set forth in claim 7, wherein the lower end of said elastic member is connected to the crossing point of said cross links via a mounting member, which has a vertical slot, in which the lower end of said elastic member is mounted.
13. A folding wheel chair as set forth in claim 1, wherein said elastic member is a compression spring, and the repellent force of said compression spring is set as said seat comes down by the user’s weight.
14. A folding wheel chair as set forth in claim 13, wherein said elastic member has guide members which are arranged parallel to an expansion direction of said compression spring and guide an elastic deformation of said compression spring.
15. A folding wheel chair as set forth in claim 13, wherein said guide member has a regulating member, whereby the repellent force of said compression spring can be regulated by adjusting the axial position of said regulating member on said guide member.
16. A folding wheel chair as set worth in claim 1, wherein a wheel brake is provided, which operates to brake the wheels in accordance with the action of said seat to the stand-up state.
17. A folding wheel chair as set forth in claim 16, wherein said wheel brake is connected to said elastic member via a transfer mechanism and operated in accordance with the stretch of said elastic member.
18. A folding wheel chair as set forth in claim 16, wherein said wheel brake is connected to said seat via a transfer mechanism and operated in accordance with the action of said seat to the stand-up state.
19. A folding wheel chair as set forth in claim 16, wherein said wheel brake consists of a lock brake operated to lock the wheels in accordance with the action of said seat to the stand-up state, and a band brake operated to lock the wheels when manually operated by a user or a carer.
20. A stand-assist seat mounted on a folding wheel chair having a pair of side frames with a pair of wheels, and a pair of cross links connecting said side frames each other, comprising:
the seat consisting of a front right section, a front left section, a rear right section and a rear left section,
whereby said front right and left sections are connected swingably to front edges of said rear right and left sections respectively via the first transverse axis at the rear edges, and are connected swingably to the front portions of said cross links respectively via a second transverse axis,
said front right and rear right sections of said seat being connected swingably to the right edges of said front left and rear left sections respectively via the first longitudinal axis at the left edges,
said rear right and left sections are connected to the cross links respectively via an elastic member,
said seat takes the substantially horizontal seating state when a load to said seat is greater than the repellent force of the elastic member,
said seat is brought in the stand-up state when said rear right and left sections are lifted up and said front right and left sections are inclined forward when the load to said seat is less than the repellent force of said elastic member.
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 comprising:
receiving at one resource of a plurality of resources, requests for the one resource from a plurality of requesters;
granting the one resource to one of the requesters according to respective requester priorities, the respective requester priorities being inversely related to a number of requests made respectively, by the requesters; and
the requesters supplying respective requester priority indications to at least the one resource.
2. The method as recited in claim 1 wherein requesters respectively supply number of requests as requester priority indications.
3. The method as recited in claim 1 further comprising granting at least one of the plurality of resources to a requester according to a round robin scheme, thereby avoiding starvation.
4. The method as recited in claim 1 wherein the one resource provides a grant indication to the one of the plurality of requesters.
5. The method as recited in claim 1 wherein the multiple plurality of resources evaluate received requests sequentially.
6. The method as recited in claim 5 wherein resources are considered in an order determined according to resource priority.
7. The method as recited in claim 1 wherein the plurality of resources evaluate received requests sequentially, and wherein a requester already granted a resource removes requests for other resources for arbitration for a next sequential resource, thereby preventing requesters from receiving multiple grants during an arbitration cycle.
8. The method as recited in claim 1 wherein requester priorities are recalculated after a resource is granted.
9. The method as recited in claim 8 further comprising requesters recalculating their requests by eliminating requests for a granted resource.
10. The method as recited in claim 1 further comprising performing multiple iterations during one arbitration cycle to allocate resources to requesters.
11. The method as recited in claim 1 wherein the resources do not transmit grant indications to requesters, each requester determining grant values according to received information from other requesters.
12. The method as recited in claim 11 wherein requesters and resources are synchronized in regards to round robin positions.
13. The method as recited in claim 1 wherein each of the requesters provides an indication of priority on a bus logically combining the indications of priority, the priority being related to a number of requests being made by each of the requesters.
14. The method as recited in claim 13 wherein the indications of priority are unary coded, one bit corresponding to one request.
15. The method as recited in claim 14 wherein the bus logically combines the indications of priority.
16. The method as recited in claim 14 wherein the indications of priority are a number of requests of respective requesters.
17. The method as recited in claim 14 further comprising a requester responding to the priority indication on the bus by not sending a request if the priority indication on the bus indicates a higher priority requester is requesting a resource.
18. The method as recited in claim 1 wherein the requesters are nodes of a network coupled to input ports of a network switch and the resources are output ports of the network switch, multiple ones of the output ports being accessible to more than one of the input ports.
19. The method as recited in claim 1 wherein the requesters are processors of a multi-processor system and the resources are memories coupled to the processors, each of the memories being accessible to more than one of the processors.
20. The method as recited in claim 1 further comprising recalculating requester priorities after each time a resource is granted to a requester.
21. A method comprising:
receiving at one resource of a plurality of resources, requests for the one resource from a plurality of requesters; and
granting the one resource to one of the requesters according to respective requester priorities, the respective requester priorities being inversely related to a number of requests made respectively, by the requesters,
wherein the one resource sends a resource priority indication to the requester being granted its request, indicative of a number of requests received by the resource, and
wherein requesters receive multiple grants from multiple resources during an arbitration iteration.
22. The method as recited in claim 21 wherein a number of arbitration iterations over multiple arbitration cycles varies dynamically.
23. The method as recited in claim 21 wherein the one resource determines which requests to grant in parallel with other resources determining which requests to grant.
24. The method as recited in claim 21 wherein the one resource sends a grant indication to a requester being granted its request.
25. The method as recited in claim 21 wherein the requester being granted its request sends an accept indication to the resource whose grant it is accepting.
26. The method as recited in claim 25 wherein a requester determines which of one or more grants to accept, in parallel with other requesters determining which received grants to accept.
27. A method comprising:
receiving at one resource of a plurality of resources, requests for the one resource from a plurality of requesters; and
granting the one resource to one of the requesters according to respective requester priorities, the respective requester priorities being inversely related to a number of requests made respectively, by the requesters, wherein requesters receive multiple grants from multiple resources during an arbitration iteration and
wherein a requester selects from among a plurality of grants according to respective resource priorities associated with each granting resource, the respective resource priorities being inversely related to a number of requests made, respectively, for each granting resource.
28. The method as recited in claim 27 wherein resource priorities are recalculated each iteration.
29. The method as recited in claim 27 wherein requester priorities are recalculated each iteration.
30. The method as recited in claim 27 further comprising the requester utilizing a round robin scheme to select from among the plurality of grants.
31. The method as recited in claim 30 wherein the round robin scheme is utilized before the requester selects from among the plurality of grants according to the respective resource priorities, the requester selecting from among the plurality of grants according to the respective resource priorities if the round robin scheme does not result in an acceptance of a grant.
32. The method as recited in claim 27 further comprising the requester utilizing a random scheme in addition to using calculated priorities to select from among the plurality of grants.
33. An arbitration apparatus for arbitrating requests from a plurality of requesters for a plurality of resources, comprising:
means for receiving requests for resources from the requesters;
means for granting requests according to requester priorities, the requester priorities being inversely related to the number of requests respectively made by the requesters;
means for selecting from among a plurality of grants according to resource priorities, the resource priorities being inversely related to the number of requests made for the respective resource.
34. The arbitration apparatus as recited in claim 33 further comprising means for preventing starvation for grants.
35. The arbitration apparatus as recited in claim 33 further comprising means for preventing starvation for requests.
36. The arbitration apparatus as recited in claim 33 wherein the arbitration apparatus is one of a distributed arbiter and a centralized arbiter.
37. The arbitration apparatus as recited in claim 33 further comprising:
means for logically combining indications of priority, the priority being related to a number of requests being made by each of the requesters.
38. A distributed arbiter comprising:
a plurality of requesters;
a plurality of resources coupled to the requesters through a transport mechanism;
wherein each requester is coupled to provide to each resource requested by the respective requester, a request indication;
wherein a requested resource is responsive to a plurality of requests to selectively grant one of the requests according to requester priorities, the requester priorities being inversely related to a number of requests being made by respective requesters; and
wherein the requested resource is further coupled to provide an indication of resource priority, the resource priority being inversely related to a number of resource requests received by the requested resource.
39. The distributed arbiter as recited in claim 38 wherein the requested resource is further responsive to the plurality of requests to selectively grant one of the requests according to a round robin mechanism.
40. The method as recited in claim 39 wherein the round robin mechanism is utilized before the requested resource selects from among the plurality of requests according to the requester priorities, the requested resource granting one of the requests according to the requester priorities if the round robin mechanism does not result in a grant.
41. The distributed arbiter as recited in claim 38 wherein each requester requesting the requested resource respectively provides a requester priority indication to the requested resource.
42. The distributed arbiter as recited in claim 41 further comprising a bus coupled to the requesters and resources, and wherein each of the requesters provides an indication of priority on a bus, the bus logically combining the indications of priority, the priority being inversely related to a number of requests being made by each of the requesters.
43. The distributed arbiter as recited in claim 42 wherein the indications of priority are unary coded.
44. The distributed arbiter as recited in claim 42 wherein a bus implements a wired-NOR of the indications of priority.
45. The distributed arbiter as recited in claim 42 wherein each requester places a unary encoded number of requests on the bus as the indication of priority.
46. The method as recited in claim 42 wherein a requester with a lower priority than indicated on the bus is responsive to the priority indicated on the bus to not send its request to a resource.
47. The distributed arbiter as recited in claim 38 wherein the requested resource provides a grant indication to a requester whose request is being granted by the resource.
48. The distributed arbiter as recited in claim 38 wherein a requester is responsive to receiving a plurality of grants from a plurality of resources to accept one of the grants according to priorities of the grants, the priorities being inversely related to a number of requests received by resources.
49. The distributed arbiter as recited in claim 48 wherein the requester accepts a grant indicating a particular resource is being allocated to the requester, according to a starvation avoidance mechanism in addition to the priorities.
50. The distributed arbiter as recited in claim 38 wherein a requester is responsive to receiving a plurality of grants from a plurality of resources to accept one of the grants according to a random priority determined for the grants.
51. The distributed arbiter as recited in claim 38 wherein the requesters are nodes of a network coupled to input ports of a network switch and the resources are output ports of the network switch, multiple ones of the output ports being accessible to more than one of the input ports.
52. The distributed arbiter as recited in claim 38 wherein the requesters are processors of a multi-processor system and the resources are memories coupled to the processors, each of the memories being accessible to more than one of the processors.
53. A computer program product encoded in at least one computer readable medium, the computer program product comprising:
a first instruction sequence executable to receive requests for one resource of a plurality of resources from multiple requesters; and
a second instruction sequence executable to allocate the one resource to one of the requesters according to requester priorities, requester priorities being inversely related to a number of requests made by each requester for the resources;
a third instruction sequence executable to supply from the requesters, respective requester priority indications to at least the one resource; and
wherein the at least one computer readable medium is selected from the set of a disk, tape or other magnetic, optical, or electronic storage medium and a network, wireline, wireless or other communications medium.
54. The computer program product as recited in claim 53 wherein the computer program product further includes a starvation avoidance instruction sequence executable to implement a starvation avoidance mechanism.
55. A computer program product encoded in at least one computer readable medium to implement an arbitration mechanism to determine which of a plurality of grants received by a requester from a plurality of resources, to accept, the computer program product comprising:
a first instruction sequence executable to receive an indication of the grants for respective resources; and
a second instruction sequence executable to accept one of the grants according to grant priorities, grant priorities being inversely related to a number of requests received by a resource.
56. The computer program product as recited in claim 55 wherein the computer program product further includes a starvation avoidance instruction sequence executable to implement a starvation avoidance mechanism to accept one of the grants.