The present invention relates to a method and an arrangement for grinding spherical products (12), such as e.g. bowling balls, in particular. Such an arrangement comprises at least one grinding machine (1) having a spherically oscillating grinding movement. A fastening plate (6) fitted on the grinding machine has a spherically shaped bearing surface (7) and a grinding product (9) fitted on this, which through its slits (13) adopts a position with accuracy of shape on the spherically shaped surface. The grinding product (9) will form a contact surface (17) in the interface, in which the grinding product cooperates with the spherical product. This contact surface then adopts a radius of curvature arranged to substantially correspond to the radius (r) of the spherical product (12). The grinding is performed with a spherically oscillating grinding movement, which is adapted to the radius of the spherical product and simultaneously coincides with the radius of curvature of the contact surface.

An adjustable stroke mechanism for a random orbital machine including a housing having a wall enclosing a cavity, an adjuster ring surrounding the housing and having a first set of gear teeth along a first portion of an inner surface, and a second set of gear teeth along a second portion of the inner surface, a counterweight having gear teeth on an exterior surface disposed within the housing, and a bearing carriage having gear teeth disposed within the housing. At least one counterweight gear that meshes with the gear teeth of the counterweight and the first set of gear teeth of the adjuster ring, and at least one bearing carriage gear that meshes with the gear teeth of the bearing carriage and the second set of gear teeth of the adjuster ring, so that movement of the adjuster ring causes movement of both the counterweight and the bearing carriage.

A polisher may include a polishing pad, a motor, a transmission device, and a mode selection device. The transmission device can transmit a rotational drive force of the motor to the polishing pad in a plurality of different modes with respect to a motion of the polishing pad. The mode selection device may be used for selecting a desired motion mode of the output member. Additionally, a motor and handle housing with an accompanying power cord may be constructed to aid in ease of manipulation of the polisher by the user with minimal interference.

The invention relates to a method for controlling an automated orbital sander, in which method an electrically powered orbital sander is moved around automatically, at constant pressure, over the surface of an object, along at least one predefined sanding path so as to perform sanding, characterized in that the instantaneous power consumed by the sander along the sanding path is measured and in that the measurement thus taken is processed in order to deduce therefrom information regarding the level of abrasion along said path and/or to detect any sanding incident that has occurred along the latter.

The invention relates to a method for controlling an automated orbital sander, in which method an electrically powered orbital sander is moved around automatically, at constant pressure, over the surface of an object, along at least one predefined sanding path so as to perform sanding, characterized in that the instantaneous power consumed by the sander along the sanding path is measured and in that the measurement thus taken is processed in order to deduce therefrom information regarding the level of abrasion along said path and/or to detect any sanding incident that has occurred along the latter.

A drive unit for imparting rotation to a drum assembly of a floor grinder. The drive unit includes a rotatable pulley positioned adjacent to and in contact with a rotatable drive surface of a driven pulley of the drum assembly and a drive surface of the drum assembly. The rotatable drive surface of the driven pulley is configured to impart rotation to the rotatable drive pulley during rotation of the rotatable drive surface, and the rotatable drive pulley is configured to impart rotation thereof to the drum assembly.

A drive unit for imparting rotation to a drum assembly of a floor grinder. The drive unit includes a rotatable pulley positioned adjacent to and in contact with a rotatable drive surface of a driven pulley of the drum assembly and a drive surface of the drum assembly. The rotatable drive surface of the driven pulley is configured to impart rotation to the rotatable drive pulley during rotation of the rotatable drive surface, and the rotatable drive pulley is configured to impart rotation thereof to the drum assembly.

An apparatus for replacing an abrasive sheet in a sanding machine comprising a working head in which it is provided a support body having an engagement surface arranged to engage with an abrasive sheet. The sanding machine also comprises a handling device arranged to actuate the support body in space according to at least two degrees of freedom. The face of the abrasive sheet facing, in use, towards the support body and the engagement surface of this comprises a mutual engagement means of removable type. For example, the mutual engagement means can provide a layer of Velcro, i.e. a velvet layer on a face and a plurality of hooks on the other face, or an adhesive layer, in particular of reversible glue layer, or a plurality of projections and recesses mutually engageable with each other, or similar engagement elements. Furthermore, is provided a removal station in which it is installed a removal device having a sharp edge arranged to remove the sheet from the support body through a plurality of operations.

An apparatus for replacing an abrasive sheet in a sanding machine comprising a working head in which it is provided a support body having an engagement surface arranged to engage with an abrasive sheet. The sanding machine also comprises a handling device arranged to actuate the support body in space according to at least two degrees of freedom. The face of the abrasive sheet facing, in use, towards the support body and the engagement surface of this comprises a mutual engagement means of removable type. For example, the mutual engagement means can provide a layer of Velcro, i.e. a velvet layer on a face and a plurality of hooks on the other face, or an adhesive layer, in particular of reversible glue layer, or a plurality of projections and recesses mutually engageable with each other, or similar engagement elements. Furthermore, is provided a removal station in which it is installed a removal device having a sharp edge arranged to remove the sheet from the support body through a plurality of operations.

An adjustable stroke mechanism has a housing with a central axis and a wall enclosing a cavity. At least one counterweight is movably disposed within the cavity. A mounting assembly is disposed within the cavity. The mounting assembly has a workpiece attachment mechanism. A stroke adjustor couples the at least one counterweight with the mounting assembly. The stroke adjustor enables the counterweight and mounting assembly to move with respect to one another such that a distance between the counterweight and the mounting assembly is variably adjusted which, in turn, variably adjusts a stroke radius of the workpiece attachment mechanism with respect to the central axis of the housing.