Patents Assigned to Stromsholmens Mekaniska Verkstad AB
  • Patent number: 5588641
    Abstract: A gas spring apparatus includes first and second cylinders each closed at both ends by end walls, first and second pistons each capable of axial displacement being disposed inside a fluid-filled inner space of the cylinders, the first piston dividing the first cylinder into two sub-spaces, the second piston dividing the second cylinder into two cylindrical chamber, first and second piston rods each of, which is connected to the corresponding piston, being mounted in a sliding and sealing fashion in one end wall, and a plurality of valves selectively communicating among two sub-spaces and two cylindrical chambers to decrease pressure inside one of the sub-spaces so as to cause the first piston to be locked for a predetermined period of time, and to cause the first and second pistons to move upwards and back to an initial position of each of the first and second pistons after a predetermined delay. The valves are openable and closable which are controlled by a control device.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: December 31, 1996
    Assignee: Stromsholmens Mekaniska Verkstad AB
    Inventor: Gunnar Sand
  • Patent number: 5580032
    Abstract: The invention relates to an arrangement for a gas spring (1). This consists of an outer cylindrical casing (1a) with a sealing end wall (1b, 1c) at either end. Of these, one (1c) has an axial bore for a piston rod (4a) passing through the bore, which piston rod is connected to a piston (4b) moving axially in the interior of the casing. The arrangement also consists of an annular cylindrical body (5) made of an elastic material. The outer cylindrical wall of the body (5) is operatively connected to the casing (1a) in a sealing fashion. The inner cylindrical wall of the body (5) is operatively connected to the piston (4b) in a sealing fashion. A certain gas pressure prevails in a space (9) defined by the cylindrical wall of the casing (1a), the other end wall (1b) and the piston (4b) and the annular surface of the annular cylindrical body (5) facing away from the end wall (1c) executed with a bore.
    Type: Grant
    Filed: September 26, 1995
    Date of Patent: December 3, 1996
    Assignee: Stromsholmens Mekaniska Verkstad AB
    Inventor: Krister Gustafsson
  • Patent number: 5435530
    Abstract: The invention consists on the one hand of a cylinder (2) closed at its ends by means of end walls (4, 5) and on the other hand of an enclosed space (10). With a piston (3) capable of axial displacement, the cylinder (2) is divided into two sub-spaces (6, 7). The space (10) communicates with the aforementioned first sub-space (6) via a first openable and closable valve (11a). The second sub-space (7) communicates with the aforementioned first sub-space (6) via a second openable and closable valve (13a). A control device (12) actuates the openable and closeable valves (11a, 13a), so that the second valve (13a) is opened when a force (F) acting upon the end of the piston rod (8) has forced the piston (3) in a direction towards the first end wall (4) and into a predetermined position. The second valve (13a) is closed again once pressure equilibrium has been achieved between the sub-spaces (6, 7).
    Type: Grant
    Filed: November 26, 1993
    Date of Patent: July 25, 1995
    Assignee: Stromsholmens Mekaniska Verkstad AB
    Inventor: Gunnar Sand
  • Patent number: 5076404
    Abstract: The present invention relates to an arrangement for a gas spring (1). This comprises a cylinder (2) with a piston (3) capable of being displaced axially therein, which marks the boundary of an inner space (4) of the cylinder (2) filled with a compressible gas-oil mixture. The space (4) varies in volume in accordance with a force (F) acting upon a piston rod connected to the piston. The invention is characterized in that the inner space is so arranged as to communicate via an openable and closable valve (13) with a closed space (10). The arrangement includes a control device (12) for actuating the valve (13), which control device is so arranged as to close the valve (13) once the piston (3) has moved past a predetermined axial position in the cylinder (2), and as to open it at a predetermined time after the moment of closing.
    Type: Grant
    Filed: May 1, 1990
    Date of Patent: December 31, 1991
    Assignee: Stromsholmens Mekaniska Verkstad AB
    Inventor: Krister Gustafsson
  • Patent number: 4896524
    Abstract: Arrangement for the ejection of a pressed component from a press tool. The arrangement consists of a number of ejection pins distributed over the press surface tool. Each of the ejection pins is so arranged as to lie during the pressing operation with its tip no higher than on a level with the aforementioned press surface, and, in conjunction with the opening of the tool after a pressing operation has been completed, as to eject the component from the tool with its tip. A characteristic feature of the invention is that each ejection pin is operatively connected via a pistion rod to a hydraulic piston. The piston is capable of axial displacement in a hydraulic cylinder, which is filled with an incompressible fluid in space between the piston and an end wall of the cylinder. The space communicates via a duct with a drive unit for the ejection pin.
    Type: Grant
    Filed: September 28, 1988
    Date of Patent: January 30, 1990
    Assignee: Stromsholmens Mekaniska Verkstad AB
    Inventors: Jan A. K. Gustafsson, Per-Goran Larsson