Abstract: A dowelling jig (1) comprises a through-hole (5) for guiding a drill (18), abutments (12, 12) and cantilever springs (13, 13) for clipping the jig to one edge (10) of boarding (11) for drilling dowel-holes (2, 2, 2) in the edge, and a peg (9) for insertion in each dowel-hole (2) in turn for drilling the corresponding dowel-hole (3, 3, 3) in a face (14) of a second piece of boarding (15). The through-hole (5) extends between parallel faces (6) to which face (7) is perpendicular. Through-hole (5) axis is perpendicular to faces (6) and (19) while peg (9) is perpendicular to face (7). Abutments (12, 12) align face (19) of boarding (11) with face (7) for drilling of holes (2, 2).

Abstract: A measuring rule has a coilable steel measuring blade extensible through an opening in a housing and is marked along its length with regularly spaced dark areas separated by light areas. Two pairs of light sensors are located near the rule each associated with a light emitter. Each sensor is 180.degree. out of phase with the other sensor of the pair and 90.degree. out of phase with the other two sensors. The outputs of each pair of sensors are used to produce a difference signal. The difference signals are used by a counter to measure the magnitude and direction of movement of the blade. Each sensor output signal is divided by voltage divider to give a divided signal and each sensor output signal is compared with the complementary divided signal at the instant the difference signal of the other pair of sensors changes state and a fault signal is generated if its minimum is larger than the maximum of the complementary divided signal.

Abstract: The plastics handle 21 of a retractable blade knife 20, which also comprises a blade 22 and a blade-slider 23, is molded in one piece in a two-part molding tool 50 which can mold several such handles simultaneously. The handle has a series of wall portions, 39, 40, 27 and 43, 44, 28, 48 alternating with apertures 45, 46, 29, 49 and 41, 42, 30 along each side 25, 26 respectively, each wall portion on each side being directly opposite a respective aperture on the opposite side, so that molding tool portions 54, 55 of the molding tool can form the inside surfaces of the wall portions for guiding the blade. Wall portions 27 are formed by molding tool portions 56 with gaps 31 for passage of a manually operable part 32 of slider 23, and also act as detents for the slider.

Abstract: A guide assembly for sawing an elongate member accurately to length to form the sides of a picture frame comprises two saw-guide units which are adjustably clamped to two guide roads by means of screws. The picture frame glass is placed between reference surfaces of blocks on the saw-guide units to determine the required distance apart of the two saw-guide units. Each saw-guide unit has two pairs of posts defining slots therebetween for the blade of a saw, to hold the saw-blade accurately at 45.degree. to the direction of elongation of the wooden member, for the eventual formation of mitred joints between the sides of the picture frame. Each saw-guide unit includes a special ridge to abut that surface of the wooden member which is to surround the edge of the glass.

Abstract: A retractable blade knife 10 comprises an elongate handle 11 which is in two halves 14, 15 clamping therebetween a replaceable blade 12 which can be extended and retracted by means of a cursor 18 and which has "break-lines" 32 for breaking off successive end portions 33. To clamp the blade 12 firmly in use, a screw 27 at the rear end of the handle can be turned to produce relative longitudinal sliding between the two handle halves 14, 15, whereupon an inclined "wedging" surface 17 at the front end of the handle 11 clamps the two halves 14 and 15 together with the blade 12 between them.

Abstract: An elongate substantially rectangular abrading tool blade, which can be used either for smoothing or for heavy stock removal, is formed of sheet metal and has a multiplicity of ground and hardened cutting teeth distributed over a cutting face of the blade and a multiplicity of associated through-the-blade apertures. The cutting teeth and associated apertures extend in several parallel rows across the blade at an angle other than perpendicular to the longitudinal axis of the blade, with several cutting teeth and associated apertures in each row, all the said cutting teeth facing the same way, namely, perpendicular to the said rows. Each said aperture is directly in front of and adjacent its associated cutting tooth relative to the direction in which the teeth face. Two longitudinal side edge portions of the blade are bent back through an acute angle relative to the cutting face from a longitudinal, substantially flat, middle portion of the blade.

Abstract: A retractable blade knife adapted for use selectively with either the long narrow standard type of blade having score lines for breaking off successive end portions when worn and a large hole at its rear end or the shorter wider type of blade, sometimes double ended, with one or more smaller holes. The knife has a two part blade carrier. One part slides longitudinally relative to the other into two click positions. In each of these positions the upper part can pivot at its front end relative to the lower part. The rear end of the upper part is spring-biased away from the lower part to engage detent means on the upper part with detent means on the casing to locate the blade carrier. The front part has two bosses of different diameters, the small diameter boss projecting above the large diameter boss. All the blades lie in the same plane in the casing when in use respectively.

Abstract: A cutting tool for sheet material, especially for opening cardboard cartons, has a disposable blade removably fixed to a handle and a guide member of bent wire also fixed to the handle for keeping the blade in cutting engagement with the sheet material and away from the contents of the cartons. A nose of the guide member is rounded to avoid damaging the carton contents and projects ahead of the cutting edge of the blade. One arm of the guide member is above the blade tip so as to keep the blade from disengagement from the sheet material. Another arm of the guide member is below the tip of the blade for preventing cans or other cartons contents from being cut by the blade. A hard point is provided for puncturing cartons which are too tough to be punctured by the rounded nose of the guide member.

Abstract: A folding blade knife comprising a blade member and two U-shaped guard members, the free ends of both U-shaped guard members being pivoted to the rear end of the blade member on mutually perpendicular non-intersecting axes, such that in storage the point of the blade member is enclosed in the folds of the two guard members, one guard member covering the blade edges of the blade member and the other guard member covering the faces of the blade member, characterized in that the two guard members and their pivotal axes are adapted and arranged so that the first guard member to be unfolded from the blade member is the guard member covering the faces of the blade member, the second guard member to be unfolded from the blade member being the guard member covering the blade edges of the blade member.

Abstract: A plane for use with disposable blades (whose longest dimension is parallel to the cutting edge) has a blade-holding part in which the blade can be released by a quick-release lever from being clamped between a rigid member and a spring-biased sheet metal member, the quick-release lever releasably supporting a bar member which engages a clamping bolt. Depth of cut is controlled by a rotary knob engaging an element intermediate the knob and the blade-holding part to move both the intermediate element and the blade-holding part up and down. Slewing of the lever is achieved by a lever which slides the blade-holding part sideways in its rib-and-groove engagement with the intermediate element.

Abstract: A blade holder, for use when sharpening and honing a blade, to hold the blade at a fixed angle to the abrasive surface, comprises a frame, one or more rollers and clamp. The frame has a front plate, against the inside surface of which is clamped the front face of the blade. Since the blade's sharp edge is between its front face and its relatively narrow underneath face, (which extends obliquely to the thickness of the blade), the location of the blade's front face by the frame's front plate enables location of the sharp edge irrespective of whether the blade has parallel faces and irrespective of how thick the blade is. The roller is mounted on a shaft at the back of the frame. One or more clamping screws extend transversely of the shaft axis through one or more screw-threaded holes in the shaft to engage a clamping wedge member which is slidably guided in the frame for clamping the blade to the front plate of the frame.