Cushioned bumper for scrapers

Claim 2

A cushioned bumper for scrapers, said bumper comprising: a housing having a base wall at one end of same and having its opposite end open, a tubular plunger structure reciprocably mounted in said housing for movement toward and away from said base wall for a stroke of predetermined length, said base wall being normal to the path of movement of said plunger structure, said plunger structure projection exteriorly of said housing through said open end of said housing and carrying a buffer plate on the projecting end thereof closing said projecting end of same, composite cushioning means operatively interposed between said plunger structure and said base wall for cushioning the impetus of impacts applied to said plunger acting longitudinally of the path of movement thereof, said cushioning means comprising: a hydraulic cushioning unit operatively interposed between said plunger structure and said base wall for hydraulically cushioning said impacts throughout said stroke length in moving from an extended to a contracted relation, said hydraulic unit being of the pressure sensitive orifice metering type and being received within said housing and said plunger structure, and one or more resilient cushioning units applied to said base wall in the path of movement of said plunger structure, a pad of resiliently compressible material mounted in said housing against abutment means made fast to said housing, said plunger structure including an abutment member made fast thereto positioned to move toward and away from said resilient cushioning unit as said plunger structure moves along its path of movement and positioned to engage said pad after a predetermined movement of said plunger structure under an impact toward said base wall, means for making said housing base wall fast to the scraper, and means for biasing said plunger structure outwardly of said housing to return said hydraulic cushioning unit to its extended relation, said housing and said plunger structure being of generally complemental quadrilateral cross-sectional configuration defining opposed side walls on either side of same, with the plunger structure side walls each including a stop lug on the outwardly facing side of same, said housing side walls being respectively slotted longitudinally of said path of movement to receive the respective plunger structure lugs, said housing side walls each having made fast thereto over their said slots a mounting plate including a stop lug disposed in the path of movement of the respective plunger structure lugs to limit movement of said plunger structure outwardly of said housing and define one end of said stroke.

Claim 3

The cushioned bumper set forth in claim 1 wherein: said mounting plates are formed with a venting perforation in alignment with the lower edge of each said slots and adjacent either end of said slots, whereby extraneous material accumulating in said slots is discharged through said venting perforations on cushioning operation of said bumper.

Claim 4

The cushioned bumper set forth in claim 1 wherein: said housing adjacent the base of said base wall is formed with spaced venting perforations, whereby extraneous material accumulating within said housing is discharged through said venting perforations.

Claim 5

The cushioned bumper set forth in claim 1 wherein: said plunger structure engages said base wall to limit movement of said plunger structure inwardly of said housing and defines the other end of said stroke.

Claim 6

The cushioned bumper set forth in claim 1 wherein said resilient cushioning units further each comprise: said pad of said resilient cushioning units being annular in configuratIon, said pad being received on a centering stem made fast to said base wall and extending toward said plunger structure, said pad being seated against said base wall on one side of said pad, and including an annular abutment member on the other side of said pad against which said plunger structure abutment member engages to compress said pad.

Claim 7

The cushioned bumper set forth in claim 1 wherein: said housing and said plunger structure are rectangular in transverse cross-sectional configuration, and wherein said resilient cushioning unit and said plunger structure are in duplicate form on either side of said hydraulic cushioning unit, said hydraulic unit being self contained in nature.

Claim 8

A cushioned bumper for scrapers, said bumper comprising: a housing having a base wall structure at one end of same and having its opposite end open, a tubular plunger structure reciprocably mounted in said housing for movement toward and away from said base wall for a stroke of predetermined length, said base wall being normal to the path of movement of said plunger structure, said plunger structure projecting exteriorly of said housing through said open end of said housing and carrying a buffer plate on the projecting end thereof closing said projecting end of same, composite cushioning means operatively interposed between said plunger structure and said base wall structure for cushioning the impetus of impacts applied to said plunger buffer plate acting longitudinally of the path of movement thereof, said cushioning means comprising: a hydraulic cushioning unit operatively interposed between said plunger structure and said base wall structure for hydraulically cushioning said impacts throughout said stroke length in moving from an extended to a contracted relation, said hydraulic unit being of the pressure sensitive orifice metering type and comprising: a hydraulic cylinder carried by one of said structures, a ram carried by the other of said structures in substantial longitudinal alignment with said cylinder and having a piston head at one end thereof slidably mounted within said cylinder to define hydraulic liquid receiving chambers on opposite sides of said head, a passage extending through said head to establish communication between said chambers through said head, hydraulic liquid filling said chambers, and means for controlling the flow of said hydraulic liquid through said piston head between said chambers under impact forces acting on said buffer plate for cushioning impacts applied to said buffer plate by the passage of the hydraulic liquid between said chambers to permit movement of said ram relative to said cylinder, said controlling means including pressure responsive valve means operating in said piston head passage for controlling said hydraulic liquid flow between said chambers under instantaneous pressures acting on the high pressure side of said ram head in accordance with a predetermined force travel relationships, and a tubular flexible sealing member received about said ram and connected at either end of same to said ram and cylinder respective to form a static type hydraulic seal between said ram and said cylinder and define in part the chamber on the lower pressure side of said ram head, and one or more resilient cushioning units applied to said base wall structure exteriorly of said hydraulic unit and in the path of movement of said plunger structure, said resilient cushioning units each comprising: a pad of resiliently compressible material mounted in said housing against abutment means made fast to said housing, said plunger structure including an abutment member made fast thereto positioned to move toward and away from said resilient cushioning unit as said plunger structure moves along its path of movement and being positioned to engage said pad after a predetermined movement of said plunger structure under an impact toward said base wall Structure, means for making said housing base wall structure fast to the scraper, and means for biasing said plunger structure outwardly of said housing to return said hydraulic cushioning unit to its extended relation.

Claim 9

A cushioned bumper for scrapers, said bumper comprising: a housing having a base wall structure at one end of same and having its opposite end open, a tubular plunger structure reciprocably mounted in said housing for movement toward and away from said base wall for a stroke of predetermined length, said base wall being normal to the path of movement of said plunger structure, said plunger structure projecting exteriorly of said housing through said open end of said housing and carrying a buffer plate on the projecting end thereof closing said projecting end of same, composite cushioning means operatively interposed between said plunger structure and said base wall structure for cushioning the impetus of impacts applied to said plunger buffer plate acting longitudinally of the path of movement thereof, said cushioning means comprising: a hydraulic cushioning unit operatively interposed between said plunger structure and said base wall structure for hydraulically cushioning said impacts throughout said stroke length in moving from an extended to a contracted relation, said hydraulic unit being of the pressure sensitive orifice metering type and comprising: a hydraulic cylinder carried by one of said structures, a ram carried by the other of said structures in substantial longitudinal alignment with said cylinder and having a piston head at one end thereof slidably mounted within said cylinder to define hydraulic liquid receiving chambers on opposite sides of said head, a passage extending through said head to establish communication between said chambers through said head, hydraulic liquid filling said chambers, and means for controlling the flow of said hydraulic liquid through said piston head between said chambers under impact forces acting on said buffer plate for cushioning impacts applied to said buffer plate by the passage of the hydraulic liquid between said chambers to permit movement of said ram relative to said cylinder, said controlling means including pressure responsive valve means operating in said piston head passage for controlling said hydraulic liquid flow between said chambers under instantaneous pressures acting on the high pressure side of said ram head in accordance with a predetermined force travel relationships, and a tubular flexible sealing member received about said ram and connected at either end of same to said ram and cylinder respective to form a static type hydraulic seal between said ram and said cylinder and define in part the chamber on the lower pressure side of said ram head, and one or more resilient cushioning units applied to said base wall structure exteriorly of said hydraulic unit and in the path of movement of said plunger structure, said resilient cushioning units each comprising: a pad of resiliently compressible material mounted in said housing against abutment means made fast to said housing, said plunger structure including an abutment member made fast thereto positioned to move toward and away from said resilient cushioning unit as said plunger structure moves along its path of movement and being positioned to engage said pad after a predetermined movement of said plunger structure under an impact toward said base wall Structure, means for making said housing base wall structure fast to the scraper, and means for biasing said plunger structure outwardly of said housing to return said hydraulic cushioning unit to its extended relation.