초록 ▼

A three runner sled includes a single steerable front runner and two directionally fixed rear runners extending from a frame. The frame has a longitudinal backbone member with an elongate seat. Each rear runner has a knee rest somewhat forwardly positioned relative to the seat. Each rear runner also

A three runner sled includes a single steerable front runner and two directionally fixed rear runners extending from a frame. The frame has a longitudinal backbone member with an elongate seat. Each rear runner has a knee rest somewhat forwardly positioned relative to the seat. Each rear runner also has a foot rest at its rearward end. This configuration results in a kneeling position for the sled operator, providing a relatively low center of gravity for the sled and operator, yet allowing the operator to readily shift his/her weight laterally for better balance and control. The telescoping steering column connecting the front runner to the sled frame includes an adjustable suspension. Independently actuated brakes are provided at the rearward ends of the rear runners, controlled by separate brake levers. Attachments may be provided for carrying the sled on a person's back, for convenient sled transport.

대표청구항 ▼

A three runner sled includes a single steerable front runner and two directionally fixed rear runners extending from a frame. The frame has a longitudinal backbone member with an elongate seat. Each rear runner has a knee rest somewhat forwardly positioned relative to the seat. Each rear runner also

A three runner sled includes a single steerable front runner and two directionally fixed rear runners extending from a frame. The frame has a longitudinal backbone member with an elongate seat. Each rear runner has a knee rest somewhat forwardly positioned relative to the seat. Each rear runner also has a foot rest at its rearward end. This configuration results in a kneeling position for the sled operator, providing a relatively low center of gravity for the sled and operator, yet allowing the operator to readily shift his/her weight laterally for better balance and control. The telescoping steering column connecting the front runner to the sled frame includes an adjustable suspension. Independently actuated brakes are provided at the rearward ends of the rear runners, controlled by separate brake levers. Attachments may be provided for carrying the sled on a person's back, for convenient sled transport. altering includes a second plate having larger openings formed therein over at least one of said chambers, the openings of the second plate being interchangeable with the corresponding openings of said metering plate. 5. A singulation head for use in a singulation mechanism for flat articles of varying size and weight, which mechanism includes a takeaway mechanism for articles exiting the head, detectors for selectively detecting article position for an article being singulated and the singulation head including: a selectively perforated belt driven across said head at a selected rate, at least two vacuum chambers positioned behind said belt so as to apply vacuum thereto when energized, said chambers being successively positioned along said belt; and a feed mechanism selectively controlling at least one of pressure and flow for at least one of said chambers to facilitate the feeding by said head to said takeaway mechanism of heavier articles to be singulated while inhibiting bleed through doubles for lighter articles to be singulated, wherein the feed mechanism operates in response to an indication from at least one of said detectors that an article has not been fed by said head for increasing at least one of the pressure/flow for at least one of said chambers to facilitate feeding of said article, wherein there is a chamber V1 adjacent a selected portion of each article at the beginning of a feed operation, and a chamber V2 downstream from chamber V1, and wherein said feed mechanism increases pressure/flow for at least V1 and wherein chamber V1 is divided into a chamber V1a and a chamber V1b, chamber V1a being between chambers V1b and V2, wherein chamber V1a, but not chamber V1b, is normally operated to feed articles, and wherein feed mechanism operates at least chamber V1b to facilitate feeding of said article. 6. A singulation head as claimed in claim 5 wherein said feed mechanism operates both chambers V1a and V1b at substantially the same time. 7. A singulation head as claimed in claim 5 wherein chamber V1b provides greater pressure/flow than chamber V1a. 8. A singulation head as claimed in claim 7 including a mechanism which provides a puff of air to chamber V1a at the end of each operation thereof. 9. A singulation head as claimed in claim 8, wherein said puff of air is sufficient to momentarily positively pressurize chamber V1a. 10. A singulation head as claimed in claim 8 wherein said puff of air is controlled from a puffer valve, and wherein a same signal triggers both chamber V2 and the puffer valve. 11. A singulation head as claimed in claim 5 including a mechanism which provides a puff of air to chamber V1 at the end of each operation thereof. 12. A singulation head as claimed in claim 11 wherein said puff of air is sufficient to momentarily positively pressurize chamber V1. 13. A singulation head for use in a singulation mechanism for flat articles of varying size and weight, which mechanism includes a takeaway mechanism for articles exiting the head, detectors for selectively detecting article position for an article being singulated and the singulation head including: a selectively perforated belt driven across said head at a selected rate, at least two vacuum chambers positioned behind said belt so as to apply vacuum thereto when energized, said chambers being successively positioned along said belt; and a feed mechanism selectively controlling at least one of pressure and flow for at least one of said chambers to facilitate the feeding by said head to said takeaway mechanism of heavier articles to be singulated while inhibiting bleed through doubles for lighter articles to be singulated, further including a fence against which a leading edge of each article is to abut, one of said vacuum chambers, V2, being the leading-most one of said vacuum chambers, said fence terminating at a distance from said belt slightly greater than a thickest article to be fed and at a point on the belt over a portion of chamber V2 between a mid-region thereof and a trailing end thereof. 14. A singulation head as claimed in claim 13, including a metering plate over chamber V2, said metering plate having openings formed therein over substantially only the portion of chamber V2 on the leading end side of said fence. 15. A singulation head as claimed in claim 13 wherein said detectors include a first detector located past a leading side of chamber V2, a second detector between said singulation head and said take-away mechanism, and a third detector at said take-away mechanism. 16. A singulation head as claimed in claim 13 wherein said fence bends in the leading direction at a selected point behind an end thereof. 17. A singulation head for use in a singulation mechanism for flat articles of varying size and weight, which mechanism includes a takeaway mechanism for articles exiting the head, detectors for selectively detecting article position for articles being singulated and the singulation head including: a selectively perforated belt driven across said head at a selected rate; at least two vacuum chambers positioned behind said belt so as to apply vacuum thereto when energized, said chambers being successively positioned along said belt and a mechanism which provides a puff of air to at least one of said chambers at the end of each operation thereof. 18. A singulation head as claimed in claim 17 wherein said puff of air is sufficient to momentarily positively pressurize said at least one chamber. 19. A singulation head as claimed in claim 17 wherein there is a chamber V1 adjacent a selected portion of each article at the beginning of a feed operation, and a chamber V2 downstream from chamber V1, and wherein said mechanism provides a puff of air to at least chamber V1. 20. A singulation head as claimed in claim 19 wherein V1 is divided into a chamber V1a and a chamber V1b, chamber V1a being between chambers V1b and V2, wherein chamber V1a, but not chamber V1b, is normally operated to feed articles, and wherein said mechanism provides a puff of air to at least chamber V1a. 21. A singulation head as claimed in claim 20 wherein said puff of air is sufficient to momentarily positively pressurize chamber V1a. 22. A singulation head as claimed in claim 21 wherein said puff of air is controlled from a puffer valve, and wherein a same signal triggers both chamber V2 and the puffer valve. 23. A singulation head as claimed in claim 19 wherein said puff of air is sufficient to momentarily positively pressurize chamber V1. 24. A singulation head as claimed in claim 17 including a fence against which a leading edge of each article is to abut, one of said vacuum chambers, V2, being the leading-most one of said vacuum chambers, said fence terminating at a distance from said belt slightly greater than a thickest article to be fed and at a point on the belt over a portion of chamber V2 between a mid-region thereof and a trailing end thereof. 25. A singulation head as claimed in claim 24 including a metering plate over chamber V2, said metering plate having openings formed therein over substantially only the portion of chamber V2 on the leading end side of said fence. 26. A singulation head as claimed in claim 24 wherein said detectors include a first detector located past a leading side of chamber V2, a second detector between said singulation head and said take-away mechanism, and a third detector at said take-away mechanism. 27. A singulation head as claimed in claim 24 wherein said fence bends in the leading direction at a selected point behind the end thereof. 28. A singulation head for use in a singulation mechanism for flat articles of varying size and weight, which mechanism includes a takeaway mechanism for articles exiting the head, detectors for selectively detecting article position for articles being singulated and the singulation head including: a selectively perforated belt driven across said head at a selected rate; at least two vac