Patents Assigned to Dolmar GmbH
  • Patent number: 6334421
    Abstract: In order to create (100) with a motor (101) which is fixed to a casing (102) and which shows an intake port (11) which is connected with a carbureter (16) for decoupling oscillations over an elastic suction hose (15), the carbureter (16) itself taking its bearing on the casing (102) by means of fixing means (21, 15), which avoids the disadvantages of the solution existing up to now and which makes possible especially a vibration-free bearing of the carbureter which is simple, easy servicing and which can be realized at low cost, it is proposed that the bearing of the carbureter (16) on the casing (102) is carried out substantially resiliently for damping or reducing the oscillations and the bearing of the resiliently hinged carbureter is carried out by means of an one-point suspension.
    Type: Grant
    Filed: November 3, 2000
    Date of Patent: January 1, 2002
    Assignee: Dolmar GmbH
    Inventors: Andreas Singer, Jochen Schoenhaar
  • Patent number: 6302078
    Abstract: A two-cycle internal combustion engine (10) with additional engine oil lubrication system comprises a fuel tank (11) which can be filled with fuel through a filling opening which can be closed with a fuel tank cap (13), as well as an engine oil tank (12) which can be filled with engine oil through a filling opening which can be closed with an engine oil tank cap (14). A regular checking of the oil-level in the engine oil tank (12) is promoted by the fact that both tanks (11, 12) with their tank caps (13, 14) are so configured that, when filling the fuel tank (11), the operating person's attention is drawn to the engine oil tank (12).
    Type: Grant
    Filed: November 29, 1999
    Date of Patent: October 16, 2001
    Assignee: Dolmar GmbH
    Inventors: Andreas Singer, Jochen Schoenhaar, Steffen Brauer
  • Patent number: 6296586
    Abstract: A tensioning device for a chain or a belt drive for a motor of a hand machine tool, especially for a chain saw or a grinding or abrasive cutting-off machine, with a longitudinally movable bracket, such as a bracing or an arm, which can be fixed together with a cover with at least one bolt with a screwable nut to a casing or to another part of the hand machine tool, whereby the tensioning device has an adjusting screw extending in the longitudinal direction of the bracket on which a rider screw is movable to-and-fro by rotating the adjusting screw, the rider screw having a trunnion extending through an opening of the bracket so that, for tensioning the chain or the belt drive, the bracket follows a movement of the rider screw.
    Type: Grant
    Filed: October 8, 1999
    Date of Patent: October 2, 2001
    Assignee: Dolmar GmbH
    Inventors: Marc Walkenhorst, Andreas Singer
  • Patent number: 6250449
    Abstract: In order to improve a centrifugal multiplate clutch with a pot-type clutch drum and a rotor which has several disk shaped plates, fixed on a motor shaft, each plate having a hub and a centrifugal weight connected by a rocker bar so that, when the no-load number of revolutions is considerably exceeded, the centrifugal weight is moved radially outwards and frictionally engages the clutch drum, the invention proposes that the plate contour is continuously tapered in its width starting from the hub to the transition of the rocker bar into the centrifugal weight.
    Type: Grant
    Filed: October 8, 1999
    Date of Patent: June 26, 2001
    Assignee: Dolmar GmbH
    Inventor: Torsten Haussner
  • Patent number: 6202625
    Abstract: The invention relates to a driving device for a motor driven vegetation cutter or the like with a two cycle engine showing an injection valve (12), a coupling placed in a coupling box (15), air intake and air blow-off devices, a fuel pump (17), a starter box (18) as well as eventual other additional sets. It is proposed so as to create a compact arrangement of the parts of said driving device with an optimal cooling and combustion to place the coupling box (15) and the starter box (18) on opposed sides of the two cycle engine and to direct the injection valve (12) with its jet direction onto the cylinder head or the ignition plug (11).
    Type: Grant
    Filed: June 11, 1999
    Date of Patent: March 20, 2001
    Assignee: Dolmar GmbH
    Inventors: Andreas Singer, Jochen Schoenhaar, Torsten Haussner
  • Patent number: 6196170
    Abstract: The invention refers to a driving apparatus for a lawn trimmer with a two-stroke motor having an injection valve, a coupling power output, air intake and exhaust gas discharge devices and a fuel pump as well as other possible additional components. For providing a compact construction and for guaranteeing the operativeness of the motor by fuel cooling and specific air guiding, the injection valve and a cooling air fan are placed on the same side of the motor cylinder block as the output coupling with the injection valve having a nozzle jet orientation directed to the ignition plug.
    Type: Grant
    Filed: June 25, 1999
    Date of Patent: March 6, 2001
    Assignee: Dolmar GmbH
    Inventors: Andreas Singer, Torsten Haussner, Jochen Schoenhaar
  • Patent number: 6172887
    Abstract: A circuit arrangement (10) for the batteryless power supply of the electronic control of a portable machine driven by an internal combustion engine, which machine possesses a d.c. voltage generator driven by the internal combustion engine, which delivers a generated voltage dependent on the number of revolutions of the internal combustion engine, which is transferred to a rated d.c. voltage (Vcc). The circuit arrangement (10) includes a first rectifier circuit (D1, C1), which converts the generator voltage (Ug) into an intermediate d.c. voltage (Uz), which permits the same, without booster batteries, to reliably and controllably supply the electronics of an engine-driven machine, especially in the starting phase, with the requisite rated d.c. voltage.
    Type: Grant
    Filed: November 9, 1997
    Date of Patent: January 9, 2001
    Assignee: Dolmar GmbH
    Inventors: Hartmut Klare, Andreas Singer
  • Patent number: 6125824
    Abstract: Disclosed is a method for controlling the injection process in a high-speed two stroke internal combustion engine (11). The method includes providing a trigger signal fixedly related to the rotational angle of the crankshaft per revolution of the injection control, providing a speed dependent A.C. voltage, whose period duration amounts to a fraction (L/n) of the time per revolution (rotation time) of the internal combustion engine (11), and controlling the injection process responsive to the trigger signal and the A.C. voltage. Accordingly, the invention provides a simple electronic injection control with optimal, accurately computable injection parameters for all speeds.
    Type: Grant
    Filed: July 20, 1999
    Date of Patent: October 3, 2000
    Assignee: Dolmar GmbH
    Inventors: Hartmut Klare, Andreas Singer
  • Patent number: 6116199
    Abstract: In order to provide a mixture-compressing two-stroke Otto engine with fuel injection into the cylinder space, in which it is in particular intended to make a homogeneous mixture formation possible, it is proposed that the combustion space (19) possesses essentially the configuration of a hemisphere and, with its combustion space axis (21), is, from the cylinder axis (20) relative to the side of the cylinder (11) located opposite the exhaust duct (14), disposed so as to be offset, the injection nozzle being disposed relative to the combustion space (19 in such a way that the upper portion of the jet cone (22) penetrates a predominant volume proportion of the combustion space (19), while the lower portion of the jet cone extends underneath the cylinder bottom plane (25) approximately obliquely to the cylinder axis (20), but outside the combustion space (19).
    Type: Grant
    Filed: April 26, 1999
    Date of Patent: September 12, 2000
    Assignee: Dolmar GmbH
    Inventors: Peter Schulz, Klaus Matthees, Uwe Mehlhose, Reinhart Doerfelt, Andreas Singer
  • Patent number: 6085720
    Abstract: In a method for controlling an injection valve (16) in a high-speed internal combustion engine with fuel injection, in which method, with each revolution of the engine, at a trigger point (TP1,TP2), a trigger signal is generated and according to the trigger signal, the injection operation is initiated, in which, for low engine speeds, the injection start is within a first range (ESB1) of the crankshaft angle of rotation and in which, for high engine speeds, the injection start is within a second range (ESB2) of the crankshaft angle of rotation, which second range (ESB2) in comparison with the first range (ESB1), is displaced in the direction "early" relative to the top dead center (OT), an optimal operating behavior is achieved in that, to each of the two ranges (ESB1 or ESB2), a trigger point of its own (TP1 or TP2) is allocated and in that, when changing between low and high engine speeds, starting from a predetermined threshold engine speed, a changeover of the control between the two trigger points (TP1,T
    Type: Grant
    Filed: September 2, 1998
    Date of Patent: July 11, 2000
    Assignee: Dolmar GmbH
    Inventors: Hartmut Klare, Klaus Loeffler, Peter Schulz, Uwe Mehlhose, Jan Lukomski, Klaus Matthees, Jochen Schoenhaar, Andreas Singer
  • Patent number: 6082312
    Abstract: In a manually operated machine such as a chain saw or the like, an internal combustion engine (10) located in a housing (17) and having an associated fuel injection mechanism (70) and an electro-mechanical module (80) is used to drive the machine. The engine (10) is a two-cycle one having a fuel container (140) arranged in or on the housing (17). The fuel injection mechanism in addition to the fuel container includes an injection valve (20) and a connecting tube (21) connecting the fuel container with the valve. For the connection between the outlet (22) of the injection valve (20) and the engine (10), a capillary tube (27) is used whose cross-sectional diameter is at maximum five times the cross-sectional diameter of the outlet of the injection valve, and the capillary tube is formed into the shape of a spring with its outlet opening directed into the engine block.
    Type: Grant
    Filed: March 8, 1999
    Date of Patent: July 4, 2000
    Assignee: Dolmar GmbH
    Inventors: Andreas Singer, Jochen Schoenhaar, Klaus Matthees, Walter Siepmann, Peter Schulz, Uwe Mehlhose
  • Patent number: 5994860
    Abstract: In a series-wound motor with electric brake, which comprises an armature provided with an armature winding and at least two exciter coils mounted on pole shoes as well as switchgear which, in the operative phase of the motor, serially connect the exciter coils with the armature winding and connect the serial connection to terminal clamps for the operating voltage and which, in the braking phase, interrupt the connection to the terminal clamps and short-circuit the armature winding by the parallel connection of a winding, an independent optimization of the braking behavior is made possible in that at least one of the exciter coils is subdivided into two part windings and in that, when braking, one of the part windings has its polarity changed and is short-circuited with the armature winding.
    Type: Grant
    Filed: June 10, 1998
    Date of Patent: November 30, 1999
    Assignee: Dolmar GmbH
    Inventors: Andreas Krueger, Klemens Krahn
  • Patent number: 5787854
    Abstract: In order to provide a device with fuel injection and lubricant feed means for internal combustion engines, preferably for manual guided equipment, such as chain saws, with a helical gear wheel (12) mounted on a crankshaft (11) or driven indirectly by the crankshaft (11), which is in engagement with a mating gear wheel (13) for driving the lubricant pump (16), wherein a piston (17) of the lubricant pump (16) forms a trunnion for the mating gear wheel (13) and possesses an oblique anterior surface (18) which bears against a lifting stud (20) adjustably retained in the housing, for aiding lubricant delivery adjustment of the lubricant pump (16), in a compact assembly, preferably a chain saw with several, lubrication circuits and a high-pressure fuel feed it is proposed that the helical gear wheel (12) be in engagement with two mating gear wheels (13,14), each connected with a drive shaft (17,26) for one lubricant pump (16,31) and/or one fuel pump (27).
    Type: Grant
    Filed: April 10, 1997
    Date of Patent: August 4, 1998
    Assignee: Dolmar GmbH
    Inventors: Ronald Uhlig, Andreas Singer, Klaus Matthees, Peter Schulz
  • Patent number: 5709594
    Abstract: In order to develop further a portable motor or engine-driven cutting-off machine with a housing (100) and an arm (12) connected thereto, on which a parting-off tool (22) is detachably secured, which can be driven with the aid of a traction means gearing (13, 14, 28) with a power transmission shaft (14) disposed on the arm (12) in such a way that, by means of simple constructional modifications, the rigidity between housing and arm is enhanced and their disadvantageous vibration behavior during cutting operations is improved, it is proposed that the arm (12) and the housing (100) or a housing half (11) be fabricated in a one-piece construction.
    Type: Grant
    Filed: December 6, 1996
    Date of Patent: January 20, 1998
    Assignee: Dolmar GmbH
    Inventors: Hans-Jurgen Korner, Wolfgang Jaensch
  • Patent number: 5687482
    Abstract: In order to provide a rotating trimming line (10) for brush cutters (100) equipped with a driving motor (119) which sets the rotating trimming line (10) that is clampingly secured with one end (13) into rotational movement, in which case the rotating trimming line (10), by virtue of the centrifugal force, extends essentially toward the outside and the rotating trimming device (10) is constructed in such a way that, in relation to its longitudinal axis (L), it possesses a varying position of the cross-section, with which, even at a high speed of rotation or at a high number of revolutions per unit time of the rotating trimming line, a substantial noise reduction can be achieved in comparison with the known rotating trimming line embodiments, which is simple to manufacture and which possesses a great stability, it is proposed that the rotating trimming line (10) possesses a radially symmetrical, viz.
    Type: Grant
    Filed: August 8, 1995
    Date of Patent: November 18, 1997
    Assignee: Dolmar GmbH
    Inventor: Martin Behrendt
  • Patent number: 5545357
    Abstract: To improve a carburetor including a main housing portion (12), in which a Venturi tube (2) and a throttling part (2a) are defined and which has an air intake side and an engine exit side, and a fuel pump (5) to the effect that, on the other hand a better starting procedure is provided and, on the other hand, the carburetor and, consequently, the engine are reliably prevented from getting flooded, it is suggested to supply fuel to the fuel pump (5) via a fuel intake (8) which is connected to the fuel tank (63) through a fuel line (64), and a fuel vapor supply (or vent) line (60) is provided which with its one end (61) is connected to the fuel intake feed channel (28) and with its other end (62) is connected to the fuel tank (63), and that in the route of the fuel vapor supply line (60) a check valve (66) is provided.
    Type: Grant
    Filed: February 22, 1995
    Date of Patent: August 13, 1996
    Assignee: Dolmar GmbH
    Inventors: Harry Radel, Christian Vick
  • Patent number: 5397054
    Abstract: A pressure jet cleaning appliance having a pressure pump (10) driven by a drive (11). The appliance includes a conduit having a primary line (14) for directing fluid into a spray gun (15) and a bypass line (19) for recycling fluid through the conduit when the spray gun is turned off. A control valve (18) has a reciprocal piston (28) responsive to fluid pressure within the primary line such that the piston moves into a closed position thereby directing fluid through the bypass line when the spray gun is turned off. The piston is directly connected to a control element (22) in the drive such that movement of the piston is translated into displacement of the control element. With this configuration, the piston actuates the control element to reduce the speed of the drive when the piston is in the closed position and to increase the speed of the drive when the piston is in the open position.
    Type: Grant
    Filed: August 20, 1993
    Date of Patent: March 14, 1995
    Assignee: Dolmar GmbH
    Inventor: Carsten Ziegs
  • Patent number: 5241931
    Abstract: An internal combustion engine with a diaphragm carburetor which provides additional fuel injection in all starting and environmental conditions. The carburetor is provided with a fuel recirculation line which communicates at one end with the fuel feed line of the carburetor, and which communicates at the other end with the fuel tank. The recirculation line is also provided with a choke for flow resistance.
    Type: Grant
    Filed: June 28, 1991
    Date of Patent: September 7, 1993
    Assignee: Sachs-Dolmar GmbH
    Inventor: Harry Radel
  • Patent number: 4560040
    Abstract: A braking device for braking the saw chain of a portable motor-driven chain saw having a safety device which has a mass member, a locking lever being provided which is pivotably mounted on the hand guard lever and bears the mass member at its free, sprung end, co-operating by its other end with a control cam which bears against the brake lever and via which the braking operation of the rotating saw chain is controlled, in such a way that the braking operation of the rotating saw chain is automatically initiated, if an uncontrolled acceleration takes place, by the saw rolling down the timber trunk to be sawn at the moment when the saw becomes jammed, with the consequence that the resulting braking force counteracts the accelerating force, so that the recoil angle of the saw is reduced.
    Type: Grant
    Filed: April 25, 1983
    Date of Patent: December 24, 1985
    Assignee: Sachs-Dolmar GmbH
    Inventors: Bengt Morner, Otto Vollertsen, Peter Thomsen
  • Patent number: D381249
    Type: Grant
    Filed: June 9, 1995
    Date of Patent: July 22, 1997
    Assignee: Dolmar GmbH
    Inventor: Frank Hubbe