Abstract: A fastener comprised of longitudinally divided bolt pieces (1,2,3) inserted into the hole, with trailing tips of the bolt pieces connected to a string (5), which is pulled out of a hole into which the bolt pieces are inserted so that the divided bolt pieces are recoupled, with head portions of the divided bolt pieces halted at the other side of the hole. The forwardly exposed shank of the recoupled bolt is fastened by means of a nut or by applying a riveting.

Abstract: A mobile platform for attaching and detaching a snow plow to vehicles and providing mobile storage and displaying of such plows. This device also provides an off the ground service platform for plows. The mobile platform has a frame shaped to hold the bottom of a curved snow plow blade and having a portion disposed at an angle which is relative to the incline at the bottom of snow plows in order to support the plow on the platform, wheels mounted on the frame so that the mobil platform can be moved and including a swivel wheel at the front of the frame, and an adjustable support on the frame and positioned to support the push frame of a snow plow, and the height of which is adjustable.

Abstract: The present application discloses a book form picture or document holder. It consists of a pair of binder covers the front of which is a picture frame and the back a rigid flat which includes support and artwork. A length of thread that is nearly invisible links a plurality of pages in a manner that avoids page by page turning when in use. An automatic method of display of successive pages of a document using this invention is also disclosed and would be of use in document displays.

Abstract: A material has a reflective surface which bears a light diffracting pattern in the form of a series of well-defined grooves and ridges, wherein the transverse cross-section of the surface has a non-cyclical sequence of peaks and troughs. The pattern is produced by a method involving the interference of a first reference beam of coherent light with a second beam of coherent light, the second beam consisting of a bundle of divergent beams all of which illuminate the same area as the first beam. Apparatus for this method has a special lens system for producing the second beam.

Abstract: An engraving machine has a cutter head (18) on a mount (17) movable in X and Y directions above a platen for holding a workpiece, the mount with the cutter head being movable in the Z direction between a raised and a lowered working position. The cutter head has a cutter (32) variable projectable from a nose cone (33), and the cutter head is also movable in the Z direction on its mount.

Abstract: A device for opening an envelope which comprises a thread adhesively attached to the inside surface of the envelope, and non-tearable strips disposed on opposite sides of the thread and adhesively attached to the outside surface of the envelope, the thread and the strips being disposed substantially parallel to each other whereby when the thread is freed from the envelope and pulled away from the envelope, the envelope can be readily opened with a straight tear line which extends along the surface of the envelope between the non tearable strips.

Abstract: A video cassette recorder and taping system is disclosed in which two video cassette decks are included within a single housing. Selection switches are provided so that a prerecorded tape may be displayed from a tape located in one video cassette unit deck while one of a plurality of inputs is being recorded on another video tape located in the deck of the second video cassette unit.