Wood Screws Research Articles

An inexpensive, quickly built shock grid for use with humans

To make a smooth, comfortable shock grid for use with barefooted human subjects, adhesive-backed aluminum tape may be applied to a wooden board and connected to a shock source through solder lugs secured to the tape grid with wood screws.

Disposable syringe techniques for obtaining small quantities of pore water from unconsolidated sediments

ABSTRACT Disposable plastic syringes, fitted with screen discs and circles of filter paper, can be used to extract small amounts of pore water from unconsolidated sediments. A wooden screw frame or large C clamp supplies pressure for field use. Supplementary techniques enable small volumes of fluid to be recovered and handled easily. The Goldberg compensating refractometer provides a useful companion tool for field studies. It can determine, in less than a minute, total dissolved solids in brackish to salt waters to an accuracy of 0.5 parts per thousand on a drop of fluid.

Active thin-film devices, Part 1

To make a smooth, comfortable shock grid for use with barefooted human subjects, adhesive-backed aluminum tape may be applied to a wooden board and connected to a shock source through solder lugs secured to the tape grid with wood screws.

The Smith-Petersen Nail

To the Editor:— Unfortunately we do have cases in which threaded Knowles pins, wood screws, and other devices have been used, with essentially the same results seen in this article. Therefore, I see no reason to change my statement that the choice of a fixation device is less important than the skill with which it is employed. My experience with the problem of the slipped capital femoral epiphysis may not be so great as that of others, but I have not found adequate reasons for discarding the proper use of a ground-down and sharpened Smith-Petersen nail. (In the case presented, a normal-sized Smith-Petersen nail was used.) I have no quarrel with the use of any device or method, provided its damage to the head is minimized (there is always some damage done to the head regardless of the surgeon or the apparatus). The extent of the original displacement and the

The industrial arts in the high school

Time and space will not permit a detailed history of the development of Industrial Arts in the high schools, therefore I will limit my discussion to a brief history of its development and of its merits as a subject worthy of its place in our American High Schools. There have been changes in the name and purposes of Industrial Arts. It probably owes its beginning to the desire and need of the early man to fashion a weapon or weapons for gathering food and for his personal protection. Hence the cave man made his crude wooden club. Then a lighter club with a sharp rock in the end, similar to the tomahawk used by the American Indian. Woodwork, or manual comes from a desire on the part of the young boy to whittle with a knife or fashion play things by the use of hammer and saw. Manual or woodwork simply aided in directing the natural desire of most boys through the use of woodworking tools. Closely correlated with the development of woodworking was the development of tools, machines, and implements to facilitate and extend its possibilities. Axes to fell the trees; adzes to hew and shape great timbers for roofs and frames for ships; saws to cut more evenly and expeditiously; knives, gauges, and carving tools to decorate; planes and files to smooth; bits to bore holes for wooden pegs or screws and bolts. Next came the development of the various labor saving machines to do most of the work that was done by hand. As an educational term, manual includes all work used as a means in general education. It differs from trade education through the apprenticeship systems in that it emphasizes the educational element rather than the commercial or industrial element. This hand training or manual emphasizes manual skill. This developed habits of accuracy, judgment and observation formed through manual activities. There are differences in opinion as to when and what country in-

A NEW TYPE STANDARD SIZE CAGE FOR RATS AND OTHER SMALL ANIMALS

This type of cage was designed in our laboratory for conducting experiments with small animals. It has been used here for several years and has proven very satisfactory for raising rats, mice, guinea pigs and other small animals. The chief advantages of this cage over other homemade cages is that it lends itself to prefabrication and easy assembly. We cut and assembled 60 cages in a few hours. It is sturdy, well constructed, materials economically priced, and easily obtained. Materials, locally purchased, cost $1.90, and this compares very favorably with that of other well constructed but much more expensive cages. The interior of this cage is so well protected with hardware cloth that gnawing of wood is no problem. Wild rats, while well known for their excellent gnawing ability did no appreciable damage to the cages even though they were kept in them for a period of several weeks. Instrzuctions for building: For purposes of efficiency, it is suggested that all of the various parts of the cage be cut out before assembling is begun. The sides and bottom units are put together separately. The sides, except the bottom unit, are covered with l2 mesh hardware cloth, using 4 penny nails for the wood and small staples to secure the hardware cloth. The bottom unit is assembled in a similar manner, but ?4- mesh hardware cloth is used. The completed sides and bottom units are assembled as shown in the photograph and drawings. The interior of the cage is completely covered with hardware cloth to protect the wood from gnawing of the animals. Metal angle irons are nailed to the tops of the end pieces; these form the groove in which the sliding top moves. A ?/4 space is allowed for the sliding top and a portion of the angle iron is bent and nailed down in the back to form a stop for the sliding top. This type of top was used because it may be completely removed and thus facilitates handling animals and cleaning the cage. It also saves on the cost of hardware because hinges, hasp and woodscrews are not needed. A steel door button to avoid accidental opening of the cage is fastened with a wood screw as is shown in the drawing. Our experience, using 60 of these cages over a period of 5 years, leads us to believe that they can be highly recommended for raising and studying small laboratory animals. . ~~~~~~~~~~~~~ ~ ~ ~ ~ ~ .... '..X :..::

Common pitfalls and complications in hip nailing

I T is not the purpose of this paper to discuss the advantages of early open reduction of fractures of the hip, anesthesia or preoperative care, alI of which have been treated thoroughty in previous papers presented before the American Association for the Surgery of Trauma, but (I) to discuss a simplified method for the accurate introduction of a nai1 into the neck of the femur and (2) to discuss the complications encountered in the treatment of open reduction of fractured hips. In our hands, the use of a guide wire accurately placed and good x-ray technic has been suficient to insert a nail properly in the neck of the femur. As soon as the patient has been prepared for surgery, the first essentia1 is an accurate reduction of the fracture obtained by a Leadbetter reduction if necessary. The injured leg is then pIaced in traction with the Ieg sIightIy abducted and the foot in interna rotation. Now a point mid-way between the pubic tubercIe and the anterior superior spine of the ilium is Iocated. This point wiIl be directIy over.the head of the femur. Then the greater trochanter of the femur is palpated and a Kirschner wire is Iaid on the anterior surface of the thigh between the mid-point and a point about I inch beIow the greater trochanter. Anteroposterior and Iateral x-rays are taken, and white the films are being deveIoped, this line is marked on the skin with a soIution of siIver nitrate, the wire is removed and the area prepared and draped for surgery. In taking the anteroposterior x-ray it is important that the x-ray tube be directly over the wire so that the tube, wire and neck of the femur are in the same pIane, and in order to do this a pIumb line is used. If this is not done and the tube is at an angle, there wiI1 be considerable error on the x-ray pIate. If the reduction as shown on these preliminary x-rays is satisfactory, the operation is then carried out. A 6 to 8 inch incision is made on the IateraI surface of the thigh extending downward from the greater trochanter and parallel to the shaft of the femur, the fascia and muscles split and the upper end of the femur exposed. A hole is driIIed through the cortex of the femur and, using the line marked on the skin with siIver nitrate as a guide, a guide wire heId paraIIe1 to the top of the tabIe is drilled into the neck and head and into the acetabulum in order to transfix the head. This is important especially in high intracapsular fractures; for when the head is first struck by the reIativeIy blunt point of the nail, it may twist around and be displaced. A second series of anteroposterior and IateraI x-rays are now taken and if they show a proper pIacement of the guide wire, a Johannson modification of the Smith-Petersen nai1 of the proper length, which is determined by measuring the length of the wire projecting from the cortex and subtracting it from the known length of the wire, is driven over the guide wire. Care must be exercised in driving the nail over the wire so that the wire is not bent at the point of the nail, and subsequently driven ahead of the nai1 into the peIvis. After the nai1 is driven, anteroposterior and lateral x-rays are again taken; and if the position of the nai1 is satisfactory and if it is necessary, a 4or j-holed Thornton flange is attached to the nai1 and then securely screwed to the shaft of the femur. AI1 screws must traverse both cortices of the femur. As stated before, accurate reduction of the fracture, insertion of the nai1 and impaction are essentia1. In spite of a11 this, the foIlowing complications, in our experience, have occurred. In two cases there was evidence that the materia1 used was defective. The first case was a sIipped femoral epiphysis in which a stainless steel wood screw was broken on insertion. The proximal fragment was removed and the case treated by fixation with two Kirschner wires. The second was a fractured hip which was treated by the insertion of a Smith-Petersen nail and Thornton flange in which the machine screw used to attach the ffange to the naiI broke and had to be replaced by a new screw. These compIications, at Ieast in part, can be prevented by better controt in manufacturing. There was one case in which there was a

STANDARD DEMENSIONS OF ALUMINUM BUILDING MATERIALS

This essay is on the proposed dimensions of various aluminum building materials discussed on the committee of architecture in the Light Metals Society of Japan, consisting on the standard size and weight of plate, strip, bar, wire, foil, pipe, structural angle, I beam, channel, band, rivet, wood screw, bolt, washer, nut, nail, etc.

An internal fixation device for the treatment of intertrochanteric fractures of the femur

A simple internal fixation device for the treatment of intertrochanteric fractures of the femur is described. This device consists of (1) a three-flanged, vitallium nail, with a channel throughout the length of its shaft and a right angle hole in its head, and (2) a vitallium wood screw. When assembled, the nail and the screw form a 90 degree angle support which makes possible early weight bearing. Included also is a detailed description of the relatively simple technic of inserting both the nail and the screw. The management of the patient before as well as after the operation is discussed. And a procedure for shortening the processing of roentgenograms during the course of the operation is outlined. Thirteen patients have been treated by this method. All but one of them were able to start weight bearing, with the aid of crutches or a walker, approximately two weeks after operation and to discard all walking aids at the end of four weeks. There was no displacement of bony fragments. Morbidity was of little or no significance. Only one patient died; death in this instance occurred a month after operation as a result of bronchopneumonia.

The Newcomen Society

THE Newcomen Society, which this year attains its majority, has recently issued its syllabus of meetings in Great Britain for the session 1941–42. The presidential address of Col. C. E. Davies will be read on November 12 after the annual general meeting. Thirteen papers are included in the syllabus. Among the subjects to be dealt with are automobiles, Suffolk windmills, spring balances, wood screws, and natural draught furnaces. Dr. Thurston is giving a paper on “The Evolution of Rider Planes for Aircraft”, Dr. Herbert Chatley one on the “Development of Mechanism in China”, and Dr. Dickinson is giving papers on Robert Stuart Meikleham and Joseph Bramah. Other papers relate to early engineering and iron–founding in Cornwall, the French civil engineers of the eighteenth century, and the famous firm of shipbuilders, Messrs. Normand of Havre. In the Newcomen Quarterly Bulletin, probably the last to be issued for the time being, are some interesting quotations from letters received from rilembers in the United States.

Origin and Manufacture of Wood Screws

(1941). Origin and Manufacture of Wood Screws. Transactions of the Newcomen Society: Vol. 22, No. 1, pp. 79-89.

History of Derbyshire Industries

THE Newcomen Society held its summer meeting in Derbyshire on June 6–9, and the members were able to pay visits to many interesting works. These included the Old Crown Derby China Works, the quarries of the Clay Cross Lime Co., the hosiery works of Messrs. George Brettle and Co., Ltd. and the Mill Close Lead Mine, Darley Dale. At various places, some interesting machines and engines were inspected and at the works of the D.P. Battery Co. two very fine water wheels were seen. After the Society's dinner on June 7, two papers were read, one on the High Peak Railway, and the other on the history of some Derbyshire industries. The latter was by Mr. Rhys Jenkins, who gave in it brief reviews of the lead, iron and other industries from the earliest records. Lead mining and smelting was carried on in Derbyshire by the Romans, and a number of pigs of lead with Latin inscriptions have been found. It is stated that there are no fewer than 4,000 disused lead mines in the county, and that some seventy years ago the output was 4,000 tons per annum. The lead smelting works near Lea appear to be the last in the county. Definite evidence of iron working go back to the twelfth century, and Mr. Jenkins traced the development from that time onwards. One interesting feature was the records of distinct industries in various localities, chains being made in one place, sickles and scythes in another, and so on. About a century and a half ago, there was a flourishing industry at Hartshorn, when hundreds of gross of wood screws were made weekly. Of Lombe's famous silk mill erected two centuries ago, nothing now remains; but its erection was an outstanding event in the history of machine building.

Month in the Patent Office

Each rib of an aircraft wing comprising upper and lower flanges connected by inclined bracing is connected to each spar at one place only. A metal wing is shown in which shaped channel members 26, 27 of the ribs are connected together by shear bracing 28, 29 certain of the members 28 being connected to gusset plates 33 secured to the centres of vertical struts 16 of the spars which have no other connections to the ribs. The metal covering of the wing is connected to the spars through wooden blocks 35, Fig. 5, secured to the flanges of the spars by wood screws passed through hollow rivets 37. Alternatively the blocks 35 may be secured to the spars by long hollow rivets 38, Fig. 6, which alternate with short rivets 37, strips of plywood 39 being inserted under the rivet heads. The spar is constructed as described in Specification 367,048, or it may have shear bracing comprising a lattice work of channel members crossing one another back to back.

MOULDS FOR MAGNESITE, CHROME AND SILICA BRICK1

Shrinkage.—Determination of allowance for shrinkage in mould manufacture is of prime importance. Design comes next. Types of Moulds.—Slip moulds including the open slip and vent bottom types, steel slip liner moulds, and the wooden knock-down screw mould. Materials Used.—Soft steel, cold rolled steel, galvanized iron and hard woods. Moulding Tools.—The slicker, short scoop, smacker, putty knife, rammer and hammer. Manufacture of Moulds.—Relation to the manufacture of all kinds of brick made from these special refractory materials. The treatment of each type of mould includes materials and method of manufacture, the materials and kinds of brick, the manufacture of which it is best suited, together with the manipulation best suited to turning out a uniformly good product. Correction of mould faults and suggestions for overcoming difficulties encountered in moulding brick find their place wherever the discussion of the various moulds and operations suggests any of the common troubles of the moulder.

An Improved Lateral Traction Splint for Fracture of Femur in Children.

In the treatment of fracture of the femur in children, we are often confronted with the fact that there is a necessity of a change of scene for those little patients that will keep them more contented during their enforced confinement in bed, and also by the frequent changes prevent the liability, especially in hot weather, of pressure ulcerations, etc. The objection to the lateral splints that I have heretofore used is that the amount of traction in a given case was not known, so I have introduced between the traction screw—which is a long wooden screw from a joiner's "set-screw"—and the block of wood—to which is fastened the two adhesive strips which extend from the lateral sides of the leg—a small pair of spring balances. such as are found in nearly every household, for weighing packages, thereby having an indicator to measure the amount of force desired. The ease

Wood-working machinery

Screwed-in threaded rods with wood screw threads feature high axial capacity and stiffness and can be used as fasteners in highly resistant and stiff timber connections. The purpose of the present paper is to review the existing literature and design rules in the present version of Eurocode 5 (EN 1995-1-1) and European Technical Assessments, to identify gaps of knowledge and to provide some proposals for the strength and stiffness of threaded rods. A collection of experimental results is used to derive simple expressions for the withdrawal capacity and stiffness. Finally, theoretical expressions for the stiffness and the capacity of laterally-loaded threaded rods are provided.