Abstract: A turbine blade having labyrinth of internal channels for circulation of coolant, the novel labyrinth geometry includes; inlet arranged on axially upstream face of terminal portion leading to an upstream duct portion having first section adjacent the inlet and a second section, the second section having reduced cross section compared to first section; a first passage intersecting first section and extending through the blade body towards tip of the blade, a proximal end of leading edge passage arranged to capture incoming air flow; a main blade passage intersecting a downstream duct portion, the downstream duct portion arranged in axial alignment with the upstream duct portion but separate from upstream duct portion; and a restrictor passage intersecting with the mid-blade passage and extending towards a mid-blade duct portion, the mid-blade duct portion in axial alignment with the upstream and downstream duct portions and in fluid communication with the upstream duct portion.

Abstract: A method of bi-casting a first component (10) to a second component (11), wherein the first component comprises a channel (13) having an opening at a surface of the component, the method comprising inserting a pin (12) into the channel (13) to a closure position to block a cross-section of said channel, positioning the first and second components to be adjacent such that at least one space is defined between the first and second components, pouring liquid bi-cast metal (15) into the at least one space between the first component and the second component such that the first component is joined to the second component by the bi-cast metal and the pin is secured in the closure position.

Abstract: A blade includes a root and an elongate portion extending to a tip, the elongate portion having an aerofoil-shaped cross-section. The aerofoil has leading and trailing edges, and suction and pressure sides. The tip includes a squealer defining a gutter at the tip, the squealer extending from the trailing edge along the entirety of a first of the suction and pressure sides, around the leading edge and partly along a second of the suction and pressure sides leaving a gap between the trailing edge and an end of the wall. A main trailing edge cooling channel extends within the elongate portion in a direction from root to tip adjacent the trailing edge and exits into the gutter. The main trailing edge cooling channel includes a bend just downstream of the exit, the exit displaced from a camber line of the blade elongated portion towards the second side.

Abstract: A turbine blade having labyrinth of internal channels for circulation of coolant, the novel labyrinth geometry includes; inlet arranged on axially upstream face of terminal portion leading to an upstream duct portion having first section adjacent the inlet and a second section, the second section having reduced cross section compared to first section; a first passage intersecting first section and extending through the blade body towards tip of the blade, a proximal end of leading edge passage arranged to capture incoming air flow; a main blade passage intersecting a downstream duct portion, the downstream duct portion arranged in axial alignment with the upstream duct portion but separate from upstream duct portion; and a restrictor passage intersecting with the mid-blade passage and extending towards a mid-blade duct portion, the mid-blade duct portion in axial alignment with the upstream and downstream duct portions and in fluid communication with the upstream duct portion.

Abstract: The inner surface of an underground tunnel defining structure, such as a culvert or pipe, is measured by apparatus including a portable hand held battery powered laser unit releasably attached to a rotor disk supported within the tunnel by an adjustable stand or tripod for rotation on a generally horizontal axis. The disk has peripherally spaced notches which receive a spring-biased latch member for positioning the disk and laser unit at predetermined angular positions about the axis. The laser unit emits a laser beam to a target on the inner surface of the structure and displays on the unit a precision distance reading from the laser unit to the target. The distance reading for each target is entered in a chart for comparison with a prior measurement reading to indicate changes in the shape or profile of the inner surface.

Abstract: A vibration damper (28) is disclosed for use in a turbomachine, the turbomachine comprising at least one turbine rotor (19) having a plurality of radially extending blades (16, 17). Each blade has an aerofoil (22), a platform (21) and a stem (20). The vibration damper (28) has a seal-region (29) which comprises a pair of sealing surfaces (24, 25) configured for engagement with respective contact surfaces (24, 25) provided on adjacent blade platforms (21). The vibration damper (28) also has a mass-region (30) which is configured to extend radially inwardly from the seal-region (29) and to terminate at a position located between adjacent blade stems (20) (FIG. 4).

Abstract: A vibration damper assembly for damping non-synchronous vibration between adjacent, spaced apart components comprises a vibration damper located in both of a pair of generally confronting passages in each of the components. The assembly comprises at least two spaced apart articulation surfaces for contact between damper and component, each of the articulation surfaces is arcuate in a first direction and is characterized by having a substantially linear portion in an orthogonal and second direction. Thereby the contact area is greatly enlarged and material loss minimized. The cross-sectional shape of the damper or passage is non-circular and there is a clearance between the damper and passage sufficiently small to prevent rotation of the damper in the passage during use.

Abstract: The inner surface of an underground tunnel defining structure, such as a culvert or pipe, is measured by apparatus including a portable hand held battery powered laser unit releasably attached to a rotor disk supported within the tunnel by an adjustable stand or tripod for rotation on a generally horizontal axis. The disk has peripherally spaced notches which receive a spring-biased latch member for positioning the disk and laser unit at predetermined angular positions about the axis. The laser unit emits a laser beam to a target on the inner surface of the structure and displays on the unit a precision distance reading from the laser unit to the target. The distance reading for each target is entered in a chart for comparison with a prior measurement reading to indicate changes in the shape or profile of the inner surface.

Abstract: A vibration damper assembly for damping non-synchronous vibration between adjacent, spaced apart components comprises a vibration damper located in both of a pair of generally confronting passages in each of the components. The assembly comprises at least two spaced apart articulation surfaces for contact between damper and component, each of the articulation surfaces is arcuate in a first direction and is characterised by having a substantially linear portion in an orthogonal and second direction. Thereby the contact area is greatly enlarged and material loss minimised. The cross-sectional shape of the damper or passage is non-circular and there is a clearance between the damper and passage sufficiently small to prevent rotation of the damper in the passage during use.

Abstract: A vibration damper (28) is disclosed for use in a turbomachine, the turbomachine comprising at least one turbine rotor (19) having a plurality of radially extending blades (16, 17). Each blade has an aerofoil (22), a platform (21) and a stem (20). The vibration damper (28) has a seal-region (29) which comprises a pair of sealing surfaces (24, 25) configured for engagement with respective contact surfaces (24, 25) provided on adjacent blade platforms (21). The vibration damper (28) also has a mass-region (30) which is configured to extend radially inwardly from the seal-region (29) and to terminate at a position located between adjacent blade stems (20) (FIG. 4).

Abstract: A multi-bladed mulching mower comprises a cutting deck having a peripheral skirt and side discharge outlet. A plurality of cutting chambers extend across the width of the deck and are defined by vertically extending shroud walls that depend downwardly from a top wall of the deck. A rotatable cutting blade is received inside each cutting chamber. The mower can be converted to a discharge/collection mode of operation by removing a portion of the shroud walls adjacent the side discharge outlet. The removed portion of the shroud walls extends laterally across the deck but is substantially less than the entire transverse width of the cutting chamber array to allow the removed portion of the shroud walls to be installed or removed through the side discharge outlet. A plurality of rotatable knobs removably attach the shroud portion to the deck with the knobs being accessible from above the deck to further ease the tasks of installing or removing the shroud portion.

Abstract: A processor array (2) employs an SIMD architecture and includes a number of single-bit processor elements. Each processor element includes an arithmetic unit (ALU) and at least one operand register (Q) for the arithmetic unit (ALU). Each processor element (PE) further includes a multi-byte bit-wise shift register. Data outputs are formed in said shift register for each byte position. Data is communicated from a selected one of the outputs to the arithmetic unit via a multiplexer (Z-MUX).In one example, the shift register is unidirectional and includes a cyclical data path which connects the least significant bit of the register to the most significant end. The register may output data from one of the outputs and shift data cyclically from the most significant to the least significant end in a single operation.

Abstract: A processor array system includes an n-bit scalar processor (2) and an m x m-bit processor array (1), m and n being integers, with m greater than n. The system also includes an array support circuit (3) which is connected between the scalar processor (2) and the processor array (1) and communicates data between them. The system may include an n-bit wide data path linking n-bit scalar processor registers in the scalar processor to the array support circuit (3) together with an m-bit wide data path linking the array support circuit (3) to the processor array (1). The array support circuit (3) includes a register interface arranged to interface the n-bit scalar processor registers to the processor array (1). The array support circuit (3) also includes an m-bit wide edge registers (ME) which is connected to the processor array (1) via the m-bit wide data path. The array may employ an SIMD architecture with each of a number of single bit processing elements having associated with it local store.

Abstract: A sequence generator for producing a sequence of binary numbers, comprises a counter, a priority encoder which encodes the contents of the counter, a memory addressed by the output of the encoder, an output register, and a logic circuit for modifying the contents of the output register as specified by the output from the memory. The generated sequence can readily be modified by changing the contents of the memory. The flexibility of the generator can be increased further by using as the counter a count register which is incremented by values from a further memory also addressed by the output of the encoder.

Abstract: A run-length decoder arranged to produce output signals in groups, each group being output in parallel. The decoder includes a position register which indicates the position, within a group, of the latest transition between signal values. The contents of this register are added to the incoming run-length code so as to calculate the number of groups to be output before the next transition and the position within the group of that next transition. The calculated number of groups is then output and a transition is introduced into the calculated position in the next group to be output.

Abstract: An array processor in which each sub-array of processing elements has a group of check-bit processing elements associated with it. The check-code processing elements have north-south interconnections, but have no east-west connections. Instead, the northernmost element of each group is connected diagonally to the southernmost element of the neighboring group, so as to permit serial transfer of check codes, over the north-south connections and the diagonal connections, between adjacent groups in the east-west direction.

Abstract: A data processing system is disclosed consisting of a plurality of data processing elements and parity processing elements. The parity processing elements hold parity bits for checking the contents of the internal registers and internal stores of the data processing elements and perform substantially the same operations on the parity bits as the data processing elements perform on the data. However, some of these operations may invalidate the parity bits. In particular, the carry result from an addition operation is not always valid. A parity valid logic circuit is therefore provided to generate a signal which indicates whether the parity bits from all the parity processing elements are valid, and hence whether the parity check performed using these parity bits is valid.

Abstract: An array processor is described consisting of a plurality of modules connected together in rows and columns. Each module has at least one special terminal which, as well as providing a connection for transfer of data between adjacent modules, also provides an output which is combined with similar signals from the other modules in the same row, to form a row response signal. Alternate modules in each row are rotated by 180.degree. with respect to each other, so that the special terminals on adjacent modules are connected in pairs. This reduces the complexity of the circuits for forming the row response signals.

Abstract: A binary adder circuit which, in response to a mode selection signal, is forced to operate as if two of its inputs were equal, irrespective of the actual value of those inputs. In this condition, the circuit acts effectively as a connector, coupling two of its inputs direct to the sum and carry outputs. The invention is useful in a circuit arrangement for performing adding and shifting operations.

Abstract: A binary adder has a switching circuit connected to one of its inputs. When activated by a mode selection signal, the switching circuit forces two of the adder inputs to receive the same input signal. In this condition the adder acts effectively as a connector, coupling two of its inputs direct to the sum and carry outputs. The invention is useful in an array processor, for performing additions and shifting operations.