Threaded screws

Usually, in AFM the position of the tip is fixed and the sample is raster-scanned. After manual course approach with fine-thread screws, motion of the sample is performed with a piezo translator made of piezo ceramics like e. g. lead zirconate tita-nate (PZT), which can be either a piezo tripod or a single tube scanner. Single tube scanners are more difficult to calibrate, but they can be built more rigid and are thus less sensitive towards vibrational perturbations. 

If a self-threading screw can be substituted, it will not only appreciably decrease mold maintenance and mold cost but most likely, with proper type selection, also give better holding power. A screw that has a thin thread with relatively deep flights can give high holding power. If the screw or plastic is preheated... 

Self-threading screws are an economical means of securing separable plastic joints. They can be thread cuttings. To select the correct self-threading screw, the designer should... 

Reaction cell. 1 Cylindrical body with 80 mm o.d. and 30 mm i.d. 2 Sealing cones. 3 Threaded screws. 4 Sapphire windows. 5 Opening for the introduction of a burner. 6 Openings for a sheathed thermocouple and two capillaries... 

Schematic cross section of a burner, to be introduced into the reaction cell. A Threaded screw. B Cone to fit into the reaction cell opening. C Injector nozzle with two concentric tubes. D Twin valve for the inlet of two gases...

In flatwire form, they compete with beryllium copper for eyeglass frames, circuit boards, and electronic-contact clips. The alloys also have been used for rivets, self-threading screws, and a variety of coldheaded parts. 

Figure 5.30 Carbon-paste electrode with threaded screw to advance paste (a) electrode assembly with machined cylinder channel (T) and threaded piston (B) (b) bow with stretched wire for slicing off old surface after the electrode plug is advanced.

In view of its significance, an extract from the basic patent for the co-rotating threaded screw [13] is reproduced here (Figs. 2.6 and 2.7) ... 

Figure 2.6 Basic patent for threaded screws - title page and patent claims...

These three groups of patents, namely, the widely used threaded screws, the kneading elements, and the modular design principle paved the way for the development of a highly effective new machine type for process engineering and plastics technology. 

Meskat, W, Erdmenger, R., DBP 862 668 Gleichdrall-Doppelschnecke mit Dichtprofil. Basic patent for the threaded screw Priority, 1944 (transferred to West Germany 1953) Extracts from this key patent are included in the text and its importance emphasized. 

I 1/A"x7/I6" coarse thread screw (same thread as takedown screw in standard stock)... 

Chirality sense The property that distinguishes enantiomorphs such as a right or left threaded screw. For molecules, the chirality sense may be described by R, S or P, M. See also absolute configuration. 

FIGURE 45.3 Bone screws (a) a self-tapping V-threaded (has a cutting flute), and (b) a non-self-tapping, buttress threaded screw. 

Rotating threaded-tip sheath sheaths equipped with a rotationally powered mechanism that bore through and disrupt fibrotic adhesions with a threaded screw mechanism at the sheath tip. 

Inserts, which have a tapped iimer hole to accept a standard threaded screw, can be self-tapping, expansion, heat or ultrasonic and can be headed or unheaded. 

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