ACME thread

The actuator mechanism for the horizontal stabiliser was located high in the tailplane area. A critical component was an acme threaded rod running in a bronze bush, difficult to lubricate owing to its small access hatch. The airline had extended the intervals for this task. 

Figure 8-22. Modified Bridgman ciosure, threaded, with ACME threads.

Most slurry pumps use a threaded shaft. The length of the shaft thread Z, is used in calculations of axial load transmitted from the torque. Some pumps use BSW and others use ACME thread, and some manufacturers have also their own thread designs to make it difficult to pirate their impellers. 

TABLE 8-13 Limiting Dimensions of American National Standard General Purpose Single Start ACME Threads. External Threads (for Shafts), Class 2G... 

A = height of the thread tooth = (major diameter - minor diameter)/2 in the case of ACME threads h = p 2 b, = thread width at the root... 

THREADED CLOSURES - TYPE OF THREADS ACME BUTTRESS MODIFIED OTHER ... 

Moulded-in internal or external threads can be used with PP. The design of threads is important to avoid the possibility of thread jumping. Thread jumping may occur if high torque is applied to the screw. If this happens, the moulded thread is still usually unharmed and can still be used. Acme or buttress type threads can be used to decrease the possibility of thread jiunping. 

ACME external thread (Table 8 13) is used for the shaft and the ACME internal thread (Table 8 14) is used for the impeller. Because the impeller thread is cast, particularly with hard metals, Class 2G is suggested because it has a wider range of tolerances than the 3G, 4G, and 5G Classes. BSW shaft threads are used on the smallest sizes. Figure 8 32 repre... 

That a company like Acme will have multiple partnership options, as listed in Chapter 17, is not unusual. When a company reaches a certain size, it will face complexity in deciding where to focus its improvement efforts. This chapter points to ways to "partition" the various supply chain "threads" into manageable parts. We include this discussion in our partnership task because we believe it is a prerequisite to devising sound partnership strategies. 

Launchbury, J., Jones, S.L.P. Lazy functional state threads. In Proceedings of the ACM SICPLAN 94 Conference on Programming Language Design and Implementation (PLDF94), pp. 24-35. ACM Press, New York (1994)... 

Probable cause was found to be a loss of airplane pitch control resulting from the in-flight failure of the horizontal stabiliser trim system jackscrew assembly s acme nut threads. The thread failure was caused by excessive wear resulting from Alaska Airlines insufficient lubrication of the jackscrew assembly. 

Contributing to the accident were Alaska Airlines extended lubrication interval, which increased the likelihood that a missed or inadequate lubrication would result in excessive wear of the acme nut threads. Alaska Airlines also extended the end play check interval, which allowed the excessive wear of the acme nut threads to progress to failure without the opportunity for detection. 

B1.5-1988(R1994) Acme Screw Threads Order No. N02788 45.00... 

Before moving on to the dynamic models of lead screw systems, the effect of thread geometry on the contact forces is considered here. The force interaction shown in Fig. 2.7 is essentially correct for the square threads where the normal force is parallel to the lead screw axis. For Acme or other types of threads, a slight modification is needed to take into account the thread angle. 

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