hey everyone i would like to need a solution for 1.9D, 1.15D and1.18D from chapter 1 book fundamentals of machine component design5th edition
1.9D An incident occurred resulting in a worker’s hand beingamputated in a machine called a “pallet notcher†that cuts notchesin 2 in. 4 in. lumber (boards), used to build pallets. The boardsmove on a conveyor to the notcher where they drop into a coveredarea about four feet long. The covered area houses two sets ofstaggered rotating knives. The boards go through the first set ofknives, notching one end, then through the second set, whichnotches the opposite end. At the time of the accident, Problems 31c01.qxd 8/3/11 9:16 AM Page 31 the worker was collecting thenotched wood from the exit area of the machine. He was pulling theboards outward as they exited the machine. He felt something hithis fingertip, and when he pulled back, his hand had been removednear the wrist. Additional facts in this accident include: (a)Prior to the day of the accident, the employee had not beenstationed at the incident pallet notcher. (b) The incident palletnotcher machine was not the employee’s usual station. (c) Theemployee was working near the exit area of the notcher at the timeof the accident. (d) The area where the boards exit the machine isapproximately 7 in. high and 19 to 20 in. from the point ofoperation. This distance is easily reachable by an employee workingat the machine exit. (OSHA report) (e) A piece of “hung†carpetlocated toward the exit of the machine hindered the visibility ofthe blades and allowed an employee to reach under it and access theblades. (f) The pallet notcher was not guarded to protect theemployees from the point of operation. (OSHA report) (g) Theemployer knew that guarding was required and was aware that thepallet notcher was not guarded. (OSHA report) (h) The employeereportedly was not informed of the location of the blades for theincident machine. (i) At the time of the accident there was nowarning label on the machine to alert the employee that a cuttingblade was within his reach. (j) The employee was not instructed touse a pull stick to retrieve boards that do not exit the machine.(k) A “willful†citation (issued when the employer knowinglycommits a violation) was proposed for a violation of1910.212(a)(3)(ii). (OSHA report) Search the OSHA regulations athttp://www.osha.gov and specifically review the section 29 CFR1910.212(a)(3)(ii). Write a paragraph relating this section to theabove incident. Also, list ways in which this accident could havebeen prevented.
1.15D D According to an OSHA director of field programs, adriller was in the process of raising the traveling block and theattached kelly and swivel assembly when an oil drilling rigaccident occurred. During an oil drilling operation, an air-chuggerwinch cable was attached to the kelly pipe as a tag line to preventit from swinging. Two of the rig hands were monitoring the kellypipe as it was pulled out of the rat hole. The chain hand picked upthe spinning chain and positioned himself near the drawworks drumas he waited for the kelly to be positioned over the hole. When hetossed the end of the spinning chain over his shoulder it becameentangled in the fast line cable as the cable was spooled onto thedrum. The spinning chain wrapped around the worker’s wrist andpulled him into the drum as the chain’s slack was drawn up. Thespinning chain also struck the worker in the groin area andfractured his leg and severed his femoral artery. The drillerstopped the drawworks before the worker was completely pulled intothe drum encasement, but the worker was seriously injured. His legwas amputated and injuries to his hand resulted in a permanentdisability. The drawworks drum was equipped with metal casing thatenclosed the drum on the lower front, top, and sides. However,there was an opening of approximately 4' 3' to allow the fast lineadequate clearances to spool back and forth onto the drum that hasno barrier guard. (See Figure P1.15D.) Apparently, the drawworksdrums used on oil well drilling sites were designed and constructedas described above without any barrier guard to protect workers inclose proximity to the drawworks drum from the hazard of theingoing nip point between the moving fast line and the drum. Searchthe OSHA regulations http://www.osha.gov and specifically reviewthe regulation 29 CFR 1910.212(a)(1), General requirement for allmachines. Write a paragraph explaining how this section would applyto the drum. Also, suggest a guard (design) that could haveprevented this accident. Problems 35 4 3 Fast line cable
1.18D An incident occurred in which a cantilevered section of awalkway under demolition fell in a bagasse warehouse area at asugar mill, resulting in the death of a worker positioned on top ofthe walkway. The incident walkway was constructed of two 2.625 in.by 10 in. steel C-channel main beams spaced three feet apart withmetal floor grating welded to the top of the C-channel beams. Thecantilevered walkway had welded-on hand rails and was approximatelythree ft in width, 11 ft in length and located at a height of 40 ftfrom ground level. This section weighed more than 800 lbs. Theworker was positioned on the cantilevered portion of the walkwaycutting through the floor grating of the walkway when thecantilevered walkway section unexpectedly gave way and fell to thearea below. The demolition of the walkway left one section of thewalkway cantilevered and supported by the metal floor grating andby an undersized weld. Demolition proceeded without an engineeringstudy of the structural integrity of the bagasse walkway as well asan adequate plan for demolition. A proper engineering study of thestructural integrity of the bagasse warehouse walkway as well as anadequate demolition plan in reasonable engineering probabilitywould have prevented the accident. Search the OSHA regulation athttp://www.osha.gov and review the sections 29 CFR 1926.501(a)(2)and 29 CFR 1926.850(a). Write a paragraph relating each section tothe above incident and describe how following the regulations wouldhave reduced the risk to employees.
