Abstract: An alignment system includes a laser transmitter and receiver. The receiver includes a linear photodetector array centered at a predetermined location with respect to machined surfaces that define a receiver reference plane. An indicator on the receiver displays a deviation of the position of the laser beam from a predetermined location on the photodetector array thereby to quantify any misalignment of a surface supporting the receiver with respect to the transmitted laser beam.

Abstract: A method and apparatus for assuring data consistency in a data processing network including local and remote data storage controllers interconnected by independent communication paths. The remote storage controller or controllers normally act as a mirror for the local storage controller or controllers. If, for any reason, transfers over one of the independent communication paths is interrupted, transfers over all the independent communication paths to predefined devices in a group are suspended thereby assuring the consistency of the data at the remote storage controller or controllers. When the cause of the interruption has been corrected, the local storage controllers are able to transfer data modified since the suspension occurred to their corresponding remote storage controllers thereby to reestablish synchronism and consistency for the entire dataset.

Abstract: A control method and system for managing operations at a well. The well operation is divided into operating phases and a set of management requirements for each operating phase are established. An associate system for each discreet management requirement produces selected outputs based upon selected inputs from all the sensed dynamic variables as well as selected inputs from knowledge bases and models. Each associate displays real time functions depending upon the processing of any operating parameter, at the selected operating phase and discreet management requirement.

Abstract: A method and apparatus for reconfiguring a file or logical volume stored on a magnetic disk storage system for optimal performance. The magnetic disk storage system contains a cache volume constituted as free storage. When appropriate, a file can be copied from its normal storage location to the cache volume with a different format to optimize the file for subsequent operations. After such operations are complete, the file can be transferred from the cache volume back to the normal storage location in the original format.

Abstract: A method and apparatus for verifying the organization of a magnetic disk storage system in which individual storage logical volumes are grouped in sequence as components of a meta device. Data concerning the organization of the meta device is stored in each storage logical volume in a dedicated storage area and in a global memory accessible to the data processing system. Whenever the integrity of the meta device is tested, the data in the configuration file and the data in the dedicated storage area are analyzed and compared. If identity exists, integrity is assumed. If identity does not exist various errors are generated to prevent use of the storage logical volume until the problem is resolved.

Abstract: A method and apparatus for emulating a magnetic tape storage device with a conventional, unmodified magnetic disk storage device. I/O output requests for the emulated magnetic tape storage device are intercepted to determine whether they involve a virtual tape resource that comprises a magnetic disk storage device. Tape requests to such a resource are converted into one or more conventional magnetic disk storage requests to effect an analogous operation. The size of the virtual tape resource can be reduced below the normal data capacity for the emulated tape storage device.

Abstract: A system and method for providing on-line, real-time, transparent data migration from an existing storage device to a replacement storage device. The existing and replacement storage devices are connected as a composite storage device that is coupled to a host, network or other data processing system. The replacement storage device includes a table which identifies data elements that have migrated to the replacement storage device. When a host system makes a data transfer request for one or more data elements, the replacement storage device determines whether the data elements have been migrated. If the data elements have migrated, the replacement storage device responds to the data transfer request independently of any interaction with the existing storage device. If the data elements have not migrated, the replacement storage device migrates the requested data elements and then responds to the data request and updates the data element map or table.

Abstract: Load balancing of activities on physical disk storage devices is accomplished by monitoring reading and writing operations to blocks of contiguous storage locations on the physical disk storage devices. A list of exchangeable pairs of blocks is developed based on size and function. Statistics accumulated over an interval are then used to obtain access activity values for each block and each physical disk drive. A statistical analysis leads to a selection of one block pair. After testing to determine any adverse effect of making that change, the exchange is made to more evenly distribute the loading on individual physical disk storage devices.

Abstract: A control mechanism for a catheter with a distal anchor. Suture threads extend from the anchor to the control mechanism. A first body contains a reel with a radial port through which the suture threads extend to be received in a termination structure on a second, partially concentric and axially coextensive body of the control mechanism. Rotation of the second body wraps and unwraps the sutures about the reel thereby to remove or introduce slack into the suture threads after the anchor device forms. Removing slack in the suture threads prevents complete straightening of the anchor device and therefore inadvertent removal of the catheter from the patient.

Abstract: A filter for use in an x-ray film cassette for cephalometric imaging. The filter is interposed between the x-ray film being exposed an adjacent x-ray conversion screen. The filter has a substantially optically opaque portion that is aligned with the patient's forehead and chin and a transparent portion. An image produced on the film depicts skeletal features in the area aligned with the transparent portion and both skeletal and soft tissue features in an area aligned with the substantially optically opaque portion.

Abstract: A dispensing pump includes first and second sleeve assemblies. Each sleeve assembly includes a rotary valve having an input and output position and a longitudinally displaceable piston that moves between a first position abutting the valve and a second position displaced from the valve. The sleeve connects to a manifold with input and output passages that align with input and output apertures in the sleeve. Withdrawing the piston with the input port of the valve aligned with the input aperture draws material into the sleeve. Moving the piston toward the valve in the output position with the output port aligned with the output passage displaces material from the manifold.

Abstract: A surgical drill guide for directing a guide tube toward a target. The guide tube has first and second sets of teeth extending along an exterior surface thereof. A through passage in an operating mechanism housing receives the guide tube. A first actuator or guide tube advancing mechanism uses a ratchet and pawl mechanism to advance the guide tube distally. A guide tube locking mechanism, that includes another ratchet and pawl mechanism prevents any unwanted proximal motion by providing a releasable lock against any unwanted proximal motion of the guide tube during use.

Abstract: A data storage facility for transferring data from a data altering apparatus, such as a production data processing site to a remote data receiving site. The data storage facility includes a first data store for recording each change in the data generated by the data altering apparatus. A register set records each change on a track-by-track basis. A second data store has first and second operating modes. During a first operating mode the second data store becomes a mirror of the first data store. During a second operating mode the second data store ceases to act as a mirror and becomes a source for a transfer of data to the data receiving site. Only information that has been altered, i.e., specific tracks that have been altered, are transferred during successive operations in the second operating mode. Commands from the local production site initiate the transfers between the first and second operating modes.

Abstract: A tissue retractor with an adjustable center claw. The retractor includes two pivoted retractor arms. An axially and angularly displaceable, spring biased clamping mechanism is positioned on the pivot axis. In a mounting position, a elongated clamping element aligns with a slot in the center claw. When the center claw is positioned and the clamp moves to its clamping position, the elongated clamping member clamps the center claw in position. The counterfacing surfaces of the center claw and the clamping member are toothed to provide a positive one-way ratchet clamp.

Abstract: A portable radiant heater comprises an electrically energized heating element extending along a vertical axis. A first, multi-faceted, concave reflective surface is positioned to the rear of the heating element. A second reflector is positioned forward of and in close proximity to the heating element. The first reflector directs radiant energy received directly from the heating element and indirectly from the second reflector forward with minimal radial dispersion.

Abstract: Load balancing of activities on physical disk storage devices is accomplished by monitoring reading and writing operations to blocks of contiguous storage locations on the physical disk storage devices. A list of exchangeable pairs of blocks is developed based on size and function. Statistics accumulated over an interval are then used to obtain access activity values for each block and each physical disk drive. A statistical analysis leads to a selection of one block pair. After testing to determine any adverse effect of making that change, the exchange is made to more evenly distribute the loading on individual physical disk storage devices.

Abstract: A method for operating a magnetic disk storage device in read/write and read-only modes. A control program in a system cache memory receives write requests for transferring data to a logical volume. The control program determines whether the write request is directed to a track that is in a read/write or read-only operating mode. Only requests to tracks having a read/write operating mode are enabled to continue. A system administrator or user controls the operating modes for each track in the disk operating system.