Tool holding

Drills and similar tools with parallel shanks are held in a drill chuck, Fig. 8.4. Many different types of chuck are available, each being adjustable over its complete range, and give good gripping power. 

By rotating the outer sleeve, the jaws can be opened and closed. To ensure maximum grip, the chuck should be tightened using the correct size of chuck key. This prevents the drill from spinning during use and chewing up the drill shank. 

A hazard in the use of chucks is the possibility of leaving a chuck key in position. When the machine is then switched on, the chuck key can fly in any direction and cause serious injury. When you remove a drill from the chuck, always remember to remove the chuck key. Never leave it in the chuck for even the shortest time. 

Better still, use a safety chuck key. Fig. 8.5, in which the central pin is spring-loaded and has to be pushed to engage. When the force is released, the pin retracts and the key falls from the chuck. 

To remove a shank from the spindle, a taper key known as drift is used. The drift is inserted throu a slot in the spindle as shown in Fig. 8.6. 

Drills and similar tools with parallel shanks are 

Drills are available with Morse-taper shanks which fit directly into the spindle without the need for a chuck. The size of Morse taper depends on the drill diameter, and the range is shown in Table 8.1. 

It is essential that tapers are kept clean and in good condition. As already stated, the drive is by friction through the tapered surfaces, and any damage to these surfaces puts some of the driving force on the tang. If this force is excessive, the tang can be twisted off. When this happens the drill has to be discarded, as there is no way of easily removing it from the spindle. 

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A critical wrinkling strain depends on the dimensions of the specimen and tooling, hold-down force, and lubrication. Any change in these factors that diminishes the radial stress (i.e., an increase in the die radius, improved lubrication, or a reduction in the blank diameter or the hold-down force) increases the risk of the formation of wrinkles. 

In this work, Comos FT (innotec, 2002), a tool holding design data, has been integrated with the model repository Rome (von Wedel, Marquardt, 2002) which is capable of storing and organizing the models which are created and used during process design activities. 

Metal injection mol ding (MIM) holds great promise for producing complex shapes in large quantities. Spray forming, a single-step gas atomization and deposition process, produces near-net shape products. In this process droplets of molten metal are coUected and soHdifted onto a substrate. Potential appHcations include tool steel end mills, superalloy tubes, and aerospace turbine disks (6,7). 

In selecting an appropriate tool, two other factors may also be important. First, it may be beneficial to leverage higher initial cost for a more full featured tool, if future appHcations are likely to need those capabiUties. Second, more than one tool may be necessary to serve the needs of different types of apphcations, ie, the adage "one size does not fit all" holds well in the tool business. Available tools in the market can be categorized into roughly three classes. 

It is well known that the resources available on the Internet are in constant flux, with new sites appearing on a daily basis and established sites disappearing almost as frequently. This also holds true for the dedicated tools used in biochemical and biophysical studies. New tools are constantly becoming available, and established tools, obsolete. Such rapid change makes it difficult to stay current with the state-of-the-art technologies in the areas of bioinformatics and computational biochemistry and biophysics. 

Fig. 18 shows a trio of autoclaves. In the foreground is a bond assembly on a wheeled tool ready to be placed in the autoclave. A technician stands at a control console next to a two-level rack used for holding multiple bond tools in the autoclave. 

The goal of COST is to ensure that Europe holds a strong position in the field of scientific and technical research for peaceful purposes, hy increasing European cooperation and interaction in this field. Ease of access for institutions from nonmember countries also makes COST a successful tool for tackling topics of a truly global nature. 

The computer simulation of models for condensed matter systems has become an important investigative tool in both fundamental and engineering research [149-153] for reviews on MC studies of surface phenomena see Refs. 154, 155. For the reahstic modeling of real materials at low temperatures it is essential to take quantum degrees of freedom into account. Although much progress has been achieved on this topic [156-166], computer simulation of quantum systems still lags behind the development in the field of classical systems. This holds particularly for the determination of dynamical information, which was not possible until recently [167-176]. 

Isotope effect between the HH, HD, DH, and DD isotopomers was used as an important tool to determine the mechanism of the double-proton transfer. For concerted degenerate double-proton transfers in the absence of tunneling, the rule of the geometrical mean (RGM) should hold in good approximation, which states that /chh/ hd = /cdh/ dd-Tunneling may lead to a breakdown of this rule but the relation /chh > hd = dh > dd should remain valid. In the absence of secondary isotope effects the relation /chh HD = DH = 2 /cdd sliould liold for a stepwise pathway, even if tunneling is involved. 

Figure 10.2 MDGC-MS differentiation between the enantiomers of theaspiranes in an aglycone fraction from puiple passion fruit DB5 pre-column (25 m X 0.25 mm i.d., 0.25 p.m film thickness canier gas He, 0.66 ml/min oven temperature, 60-300 °C at 10 °C/min with a final hold of 25 min) permethylated /3-cyclodextrin column (25 m X 0.25 mm i.d., 0.25 p.m film thickness canier gas He, 1.96 ml/min 80 °C isothermal for 20 min and then programmed to 220 °C at 2 °C/min). Reprinted from Journal of High Resolution Chromatography, 16, G. Full et al., MDGC- MS a powerful tool for enantioselective flavor analysis , pp. 642-644, 1993, with permission from Wiley-VCH.

The tool Joint holds drill pipe together, and the shoulders (similar to drill collars) form a metal-to-metal seal to avoid leakage. The tool Joint threads are designed to be made up with drilling fluid containing solids. Clearance must be provided at the crest and root of threads in order to accommodate these solids. Therefore, the shoulder is the only seal. To keep the shoulders together, proper makeup torque is required. 

L = half the distance between tool joints, L = 180 in. for Range 2 drill pipe. Equation 4-75 does not hold true for Range 3 drill pipe. 

Check slip areas for longitudinal and transverse cracks and sharp notches. Check tool Joints for wear, galls, nicks, washes, fins, fatigue cracks at root of threads, or other items that would affect the pressure holding capacity or stability of the Joint. 

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