Search

A mechanics-of-materials theory of the nonlinear deflection of helical spring within and beyond the elasticity limit was developed. The theory examined the nonlinearity due to the combined stresses of the torsion and bending of spring element by assuming the elastic–perfect plastic material obeying Tresca yield criterion. Free rotation of spring around the spring axis was taken into account. It was shown in experiment that the stress–strain curve of a piano wire was close to elastic–perfect plastic one. The outcome of the theory was compared with the experimental result of nonlinear load–deflection curves in plastically extended helical spring made of the piano wire.

The investigation on the fractured surface of steel wires in the tensile test and torsion test has been carried out using stereomicroscopic technique. The analysis has been done on cold drawn wires subjected to different pass schedules. Investigation revealed that pass schedule having optimum true strain resulted in the best mechanical properties. Hot rolled piano wire rod having carbon percentage 0.87% has been used in the investigation. The fully pearlitic microstructure is developed during lead patenting process of wire rod at 950 ℃. The wire rod has been reduced from 7.00 mm diameter to 2.6 mm wire diameter by subjecting it to three different pass schedules. The investigation revealed that highest UTS and TS properties are achieved in pass schedule-1 and pass schedule-2 respectively in the cold drawn wire of diameter 2.60 mm. The high reduction rate per die in pass schedule-1 has a negative effect on torsion strength whereas the low reduction rate per die in pass schedule-3 has negative effect on torsion strength as well as tensile strength.

Already in the late 1880’s, there were patents for systems (f.e. Jackson and Doehring) which can be seen as pre-stressed concrete. Further system developments followed well into the 1920’s, but all the systems failed because of the steel quality, and of its inherent limited strength. Some researchers (f.e. Wettstein-Boards) used steel wires with small diameters. In the 1920’s and 1930’s, Hoyer utilized very small diameters, called piano wires, as pre-stressing steel, which had a higher strength as the ones used at that time. At the same time, the French engineer Freyssinet established a pre-stressing system that made use of thicker bars. To transfer the high pre-stressed forces to the concrete, defined anchorage points were necessary. In contrast, these anchorage systems were not necessary in the Hoyer system because of the force and surface ratio of each single piano wire (known as the Hoyer effect).

High resolution 200 kV scanning electron microscopy has been used to study in situ the tensile deformation and fracture of a range of pearlites, from relatively coarse of mean interlamellar spacing about 400 nm, to very fine of mean spacing about 90 nm. The coarse pearlites contained colonies in random orientation, whilst the fine pearlites were from both the lead patented condition (containing randomly oriented colonies) and patented and drawn rod (containing colonies aligned along the rod axis). The latter samples in particular contain a structure similar to that of high strength piano wire. It was found that there were considerable differences in the tensile deformation behaviour between fine and coarse pearlites. The coarse pearlites deform by rather coarse slip in the ferrite, inhomogeneous slip in the cementite and whole colony rotation, final fracture being a relatively clean process in which crack growth is aided by brittle fracture of cementite lamellae. The fine pearlites deform by relatively homogeneous slip in both the cementite and ferrite. In the case of the axially aligned fine pearlite, as in drawn rod, the cementite is so ductile that it may even neck down to produce small fragments. The final fracture of fine pearlite is much more complicated than the coarse, with considerable branching and little sign of cavity growth to aid the crack growth process. A model is proposed to account for the differences in behaviour between coarse and fine pearlites. based upon a combination of pile-up and fibre loading stresses, in which the operating deformation mode is largely determined by which type of mechanism is dominant.

The purpose of this study is to develop a new type of coated wire electrode for fine-wire EDM. A piano wire with a very high tensile strength is coated with an electrically conductive brass layer to achieve high-speed and high-precision wire EDM. In our previous studies, by using a thin wire of 50 μm in diameter, the thickness and quality of the brass coating layer were optimized, and the effect of surface unevenness was also discussed. In this paper, the effects of the oxidation of the wire surface and high-resistance layer on the wire electrode were experimentally investigated. It was found that more sparks occur selectively in front of the wire and less sparks on the side surface of wire with the high-resistance layer on the wire surface. Consequently, the kerf width decreased and the removal rate increased with the optimum thickness of the layer. Also, the occurrence of a short circuit between the wire and the machined surface was reduced because of presence of a high-resistance layer on the wire surface.

The purpose of this paper is to modify the resin binder for developing resin-bonded diamond wire saw. The optimization of components with different ratios in the resin binder was investigated using orthogonal design experiments. Besides, the resin-bonded diamond wire saw was developed using the piano wire (the diameter is 0.2mm), the modified resin and the diamond abrasive (the diameter is 20~30μm). Good surface quality and slicing performance were obtained when slicing silicon crystal using the resin-bonded diamond wire saw we made in the experiments.

This report deals with an innovative method (Own-Weight Cantilever Method) to measure Young’s modulus of flexible thin materials. A newly developed method is based on the large deformation theory considering large deformation behaviors due to own-weight in flexible thin materials. Analytical solutions are derived by using Bessel Functions. By means of measuring the horizontal displacement or the vertical displacement at a free end of a cantilever, Young’s modulus can be easily obtained for various flexible thin and long materials. Measurements were carried out on a piano wire. The results confirm that the new method is suitable for flexible thin wires.

The construction of The Engineering Materials Diffractometer, TAKUMI of J-PARC has been finished on March 2009, and the commissioning has been started from September 2008 being parallel with the final stage of the construction. In the commissioning, after checking the validity and the stability of the detectors and the data acquisition system, powder diffraction data of an austenitic steel alloy with 10 mm diameter without beam collimation (high intensity mode) was measured, and the resolution Δd/d of 0.4% was confirmed, as designed. Further commissioning was done also with 2 mm diameter of annealed piano wire with combination of beam collimation (high resolution mode), and the resolution Δd/d of less than 0.2% was confirmed to be achieved. TAKUMI adopted an event mode data recording method. It was found that the recording method is very useful to manipulate data as we like, for instance, detector range, time of flight binning width and time resolved data, even the experiment has been finished.

The purpose of this study is to develop a new type of coated wire electrode for fine wire EDM. Piano wire with a very high tensile strength is coated with an electrically conductive brass layer to achieve high-speed and high-precision wire EDM. In our previous papers, using a thin wire of 50μm diameter, the thickness and quality of the brass coating layer were optimized and the effect of the tensile strength of the piano wire used as the core wire was discussed. In this report, the effect of unevenness of the brass wire electrode surface was experimentally investigated. As a result, it was found that by using wire with relatively large surface unevenness, the machining rate increased because of the high discharge frequency. Also, a more uniform distribution of the discharge location was confirmed by high-speed observation of the working gap during the process. In addition, the electrostatic field in the gap between the wire electrode and workpiece surface was analyzed and the reason for the high machining rate for the wire with relatively large surface unevenness was discussed from the viewpoint of the distribution of electric intensity distribution on the wire surface.

Wool fibers are “impact cut” with a rotating blade made from piano wire at various positions along the fibers. The force transmitted to the base of the fibers decreases markedly when a critical velocity (from 140 to 270 m/s) is exceeded, with corresponding improvement in the cut surface. The velocity of the wire required for impact cutting varys according to the length of the fiber above and below the impact position; fibers with long lengths above the wire impact position are impact cut at lower wire velocities than shorter fibers. Fibers impact cut above the critical wire velocity are cut by tensile failure of the fiber, produced by the inertia of the fiber being accelerated by the impacting wire. To prevent damage to the fiber tip, the feed rate of the cutter into the wool should be high. Impact cutting may be a viable means of harvesting wool from skins or even live sheep.

An apparatus for fabricating diamond powders by means of arc-discharge plasma jet CVD (chemical vapor deposition) method was developed with an attachment for collecting the fabricated powders. It was found that a nickel substrate is the best material for fabrication and a scratching brush made of piano wire of diameter 0.2mm is fit for collecting diamond powders. With this apparatus, diamond powders of diameter 15μm can be fabricated in 5 minutes, and the collecting ratio is 60%, that is 12.4mg per hour.

This paper demonstrates a low stiffness compliant joint design obtained by balancing the energy stored within individual components of the mechanism. As a step toward a fully-compliant zero-stiffness joint, this paper presents the design of a partially-compliant joint. A wireform torsion bar partially compliant joint was optimized using a pseudo rigid body model. A low stiffness design was obtained by balancing the energy stored within individual components of the mechanism. The joint was then fabricated using piano wire, polypropylene and Delrin®. During testing it was found that friction in the joint was greater than any internal forces allowing the joint to be neutrally stable in all positions. Dynamic force deflection data on the joints was collected in order to investigate the friction characteristics. The Delrin® joint exhibited only Coulomb friction while the polypropylene model exhibited both Coulomb and viscous friction.Copyright © 2011 by ASME

1. There is an extreme-form relationship of the mechanical (σ0.01, σ0.01/σt) and physical (δ, γ) properties of carbon steel cold-drawn wire to carbon content (0.51–0.92%). The maximum in these properties corresponds to a carbon content close to the eutectoid. 2. The integral acoustic parameter Y characterizing the sound quality of the string has a similar concentration relationship. 3. There is a correlation relationship between the levels of mechanical and physical properties and the acoustic parameter. The highest correlation relationship is observed between σ0.01 and σ0.01/σt and Y. 4. A close level and uniform residual macrostress distribution in the section has a favorable influence on the acoustic parameter Y. This is obtained by a special postdeformation treatment, a short temper under load at 350–400°C for 1–2 sec with simultaneous elongation of the wire by 2%. As a result Y increases by 15–22% and the quality category of the string increases.

In the present paper, piano wire on which spiral grooves are ground continuously is developed and it is used for a multiwire saw as a tool. The spiral-grooves ground round about the wire possess a sort of “abrasive grain carrier effect”. Accordingly, the abrasive grains can easily enter into the part being processed. This report deals with the mechanism of a trial apparatus to make the spiral-grooved wire tool and with the slicing characteristics of the spiral-grooved wire tool. The results obtained through the theoretical analysis and a series of experiments are as follows : (1) Theoretical results considered on the basis such assumptions that a holding effect of abrasive grain in slurry is related to volume in the hollow of spiral grooves are approximately confirmed by experiments (when the grain size is same or less with grooves depth). (2) Machining efficiency used the spiral-grooved wire tool shows two times as much as the normal wire tool. (3) Wear of multigrooved pulley used the spiral grooved wire is slightly larger than the case of ordinary wire. (4) Thickness of the sliced wafer used the spiral grooved wire is as thick as the case of ordinary one.

A device to measure soil penetration resistance in a root box (24cm×2cm×40cm) was developed, and its validity was examined for the revised root box method. The device was constructed with the metal probe (2.3 mm diameter and 50 cm length piano wire), strain gauge, linear displacement transducer, reversible motor and X-Y recorder. The main characteristic of this device is to push the needle type probe into the soil continuously about 40 cm downward at a constant rate to measure the penetration resistance easily and quickly as a function of soil depth.Edge effect was examined using probes with different diameters ranging from 0.95 to 2.3 mm. Edge effect was found to be negligible for any measured soil resistance value. Comparing spot resistance and continuous resistance, the skin friction was almost statistically constant (meaning it did not accumulate) under around 10 cm soil layer. The trend of the variation of both resistances as a function of soil depth was similar especially in the pattern of their peaks. Thus, the measured values were considered to be valid and therefore practical to use in determining penetration resistance as a function of soil depth, as a relative value.Age hardening process of the soil in the root box as a function of soil depth was examined under submerged condition. Penetration resistance tended to get bigger as soil depth increased.

At present, wire saws are widely used for the hard brittle material in semiconductor and photovoltaic industry. Though many developments have been made using new types of abrasive grain and bond developments to increase the performance, there still are disadvantages in the existing wire saws. Therefore, this paper presents a new method using ultraviolet-curing resin as a bonding agent to develop a new fixed-abrasive wire saw. It makes that the manufacture of wire saw are low cost, high efficiency and environment friendly. In addition, this paper discusses some pretreatment measures in the manufacturing process. The experimental results proved that the surface pretreatment plays an important role in improving the adhesion between resin layer and piano wire.

Fluid-elastic instability (FEI) is the cause of mechanical failures and expensive damage in tube bundle heat exchangers. The purpose of this experimental study is to develop a methodology to analyze the vibrations due to fluid-elastic instability in a tube array. The motions of a square array of 15 stainless steel vibrating tubes (∅ 25.4mm) in water cross-flow, suspended using stainless steel piano wire have been recorded with a CCD camera. The captured images are analyzed using two different methods. The individual motion and relative motion of the tubes are reported and can be used for computational model validation. The relative displacement of the tubes allows identification of the most potentially damaging patterns of tube bundle vibration. A critical reduced velocity may be determined by specification of an allowable limit on tube motion amplitude. Eventually, critical velocities for various tube array configurations and flow conditions can be measured and compared with existing criteria for heat exchanger design and operation.Copyright © 2003 by ASME

The experimental identification of a long flexible rotor with three magnetic bearing journals is presented. Frequency response functions are measured between the magnetic bearing journals and the sensor locations while the rotor is suspended horizontally with piano wire. These frequency response functions are compared with the responses of a rotor model and a reconciliation process is used to reduce the discrepancies between the model and the measured data. In this identification, the wire and the fit of the magnetic bearing journals are identified as the sources of model error. As a result of the reconciliation process, equivalent dynamic stiffness are calculated for the piano wire and the fit of the magnetic bearing journals. Several significant numeral issues that were encountered during the process are discussed and solutions to some of these problems are presented.

This demonstration will use a piano wire stretched between two pieces of aluminum exactly 100 cm apart. Plucking this wire will set it into vibration, generating sound waves that we can hear. Touching the wire at different locations along its length will change the way the wire vibrates and, therefore, change the sound we hear.

In the process of studying sound absorption in magnesium sulfate solutions as a function of pressure, a 100 L titanium sphere (a spare ballast tank for the WHOI researc submarine ALVIN) was used up to 300 atm. In calibrating the losses due to the sphere with pure water, Hsu found a resonant mode at 25 kHz (using a HP microHz synthesizer) with a very long decay at 1 atm and 25 °C; a straight line 50 dB decay of 70 s. This means that ultrasonic absorption in the titanium sphere (4 Al, 6 Va alloy) filled with water is 5.5 exp(−7) N/cm. This is four times greater than that of water at 25 kHz. Therefore, subtracting the absorption of water yields an upper limit for absorption in titanium of 4.1 exp(−7) N/cm. The 0.9 m sphere was suspended from two loops of piano wire in a steel vacuum chamber. The resonance (Q=955 000) required considerable attention to insuring pressure, temperature, and frequency control, as well as the usual degassing of the liquid. Discussion of results and details will be presented. [Research supported by ONR.]

Pure sound piano wire is a stainless‐steel wire that has only recently entered the U.S. market. Because of its different composition, which makes the wire more malleable, it should have a considerably lower amount of inharmonicity compared to regular steel wire. Measurements were conducted on several pianos with regular piano wire (Rosslau and Mapes) and pure sound in order to assess their differences in inharmonicity and tonal qualities. The pure sound wire produced measurably less inharmonicity than regular wire on the same kind of piano. However, this difference is much smaller compared to the difference between small and large pianos. This presentation will explain the methods of measurement and analysis, as well as simulations that were implemented in order to analyze the effect that inharmonicity has on the temperament, octave stretching, and interval patterns. [The Brigham Young University Department of Physics is acknowledged for the funding it provided for this research.]

The purpose of this study is to develop a new type of wire electrode, in which piano wire with very high tensile strength is coated with electrically conductive layer, such as brass or zinc, in order to attain high speed and high precision wire EDM. In this report, using a trial-made thin wire of 50μm in diameter, the optimum thickness and quality of brass layer were experimentally investigated for higher performance fine wire EDM. Furthermore, the influence of the tensile strength of piano wire used as a core wire was discussed. As a result, the coated brass with copper content of 60-70% is effective and the thickness of coated brass is needed to be more than 1.45μm for high removal rate.

Piano wire is a specific elastic element, which in most musical instruments is a source of sound vibrations of a specific frequency. In the production of such wire much attention is paid to an analysis of technological methods providing high functional properties for it. The present work concerns the effect of steel purity with respect to nonmetallic inclusions on the parameters of the acoustic properties of wire used for the production of strings of musical instruments.

Due to certain nonideal characteristics, namely stiffness, the overtones produced by piano wire deviate from a perfect harmonic series. The mechanism by which this occurs is well understood for the plain wire that is used in the treble region of a piano. The problem becomes much more complex, however, when considering the wound wire that is used in the bass section. Previous methods of analysis have had varying levels of agreement with my experimental data but they all lose correlation when applied to the lowest five to ten notes. [H. Fletcher, J. Acoust. Soc. Am. 36, 203–209 (1964)] There are certain assumptions or simplifications in these methods that breakdown for these large wires. Through finite element analysis techniques and further experimental investigation, it is hoped that an understanding of how the physical properties of bass piano wire affect its inharmonicity. This research may lead to a new wire design that may resolve tuning and tonal quality problems present in pianos today.

This paper proposes a method for making wire tools. It has been known that wire tools are used for lapping, EDM, etc. But their removal rate is very low. Then a wire tool is developed to which 10μm diamond grains are adhered by nickel plating. φ0.2mm nude wire, copper wire or piano wire, is wound from the first drum to the second one at a given speed. On the way it is plated nickel in the grains pool and diamond grains are taken in the niekel layer. By this method the number of adhered-grains can be increased. The followings are obtained. The higher the current density is, the more the number of adhered-grains are. But when it is too high, either the wire tools surface becomes rough or cracks occur on the nickel layer. The higher wirevelocity is, the less the number of adhered-grains are. When it is too high, diamond grains aren't taken in the nickel layer. On 2.27-4.55A/dm2 and 7.24-18.1mm/min, the expected wire tools can be obtained.

In the second paper, some remarkable results concerning the modification of the machine itself are described.Summary and Conclusions :1) To test the lathe for the accuracy concerning the bed surface and the carriage travel, a fine steel piano wire was stretched longitudinally above the bed under a certain amount of tension the deviation with regerd to the bed surface was observed with a micrometer microscope. Previously the wire was heated electrically under less tension to get rid of its initial distorsion to a great extent.2) The bed surface was scraped so as to get the readings within the limit of 0.05 mm (over 7.6 m length in the vertical plane).3) The readings of the carriage travel were within the limits of +15μ and -10μ (over 3 m length in the horizontal plane).4) A crowning mechanism which is simple and reliable was deviced.5) The error in the diameter of the rubber roll finished by this machine tool was within ± 0.03mm.

The problem here treated is that of finding the longitudinal motion of a long coil spring suspended vertically from a rigid support: the spring being sufficiently ``soft'' and long that it stretches appreciably under its own weight. Thus the tension and linear density each vary from top to bottom of the spring. A general solution involving displacements from the stretched static position is obtained and applied to three specific sets of boundary conditions; first, the lower end free, second the lower end rigidly fixed and lastly with a weight attached to the lower end. The natural periods corresponding to the first three fundamental modes of motion for each of the three conditions mentioned above have been determined experimentally for a long coil spring of piano wire and the results compared with the theoretically computed values. Before experimental results are given it is shown, by a second form of the equation of motion, that the natural frequencies of a spring are not affected by stretching.

The Autotrephon, described in Stanley, 1951, though very carefully designed, is somewhat complicated, and the experience of two years has shown that there are some points with respect to its operation and maintenance which should be placed on record. Warm-chamber controls. The setting of the thermostat for the humidifier heater (Stanley 1951, TH-3, Fig. 11) is very important. If it does not cut in and out within about 0..10 C., of the warm-chamber temperature, quite pronounced surges will occur in the temperature of that chamber. These will show as rather regularly spaced spikes or peaks on the temperature record. Under dry room conditions, where humidification is frequent, these spikes may run together to form a saw-tooth record. Dirty contacts on the warm-chamber thermostat (ibid., TH-1, Fig. 3) produce a very irregular variation in the temperature record. When the heater of the warm chamber (ibid., H, Fig. 3) operates, it causes a small rise of temperature (about 0.30 C.) in the air flowing down the lateral airchannels of the warm chamber. As the wet-bulb thermometer is set in this stream (ibid., WBT, Fig. 3), readings should not be taken when the heater is operating. A neon pilot light should be wired in parallel with the heater to act as an indicator. When running with the warm-chamber temperature very close to that of the surrounding room, it will be found that the chamber tends to control on the cooling system during the day, and on the heater at night. This produces a reiterated "step" effect on the record. This cannot be eliminated, but it can be minimized by making the differential on TH-1 as small as possible. The differential should be reduced to the point where the cooling system just fails to operate from the minute overshoot of the heating system. This will give a differential of perhaps 0.15 to 0.20 C. The differential of the humidistat (Ibid., Fig. 5) should not be set too fine, as the contact arm (ibid., CA, Fig. 12) naturally has a rather large swing. Experience is the only guide, but the total gap between the contact arm and the fixed contacts can be about 1/32 in. If the apparatus is shut down, the tension on the hairstrand should be released by turning the adjusting nut AN (ibid., Fig. 12) until the strand is limp. If this is not done, the hairs may break on a dry day. To prevent the hair-strand twisting when the adjusting nut is turned, a small cross-pin should be put through the rod R (ibid., Fig. 12). This should be located just where the end of the dotted pointer touches the rod, R, in Figure 12. It can be installed by sweating a brass sleeve (1/16 O.D.) over R, and drilling through this assembly, and sweating in a 34-in. length of piano wire. If this wire is held between finger and thumb of the left hand while AN is turned with the right, adjustments are readily made. The end-clips of the hair-strand were not clearly shown in Stanley 1951, and one is therefore shown herewith as Figures 1A and 1B. The clip should be milled out of non-thermoplastic bakelite, and cannot be re-used. The hairs are ordinarily human hair. We have not found that blond hairs are essential. The hairs need only be washed with ether prior to use, to wash off grease. Any good grade celluloid cement will do for cementing the hairs into the clip, but it is important that they be stretched evenly before cementing. This may be done by cementing into one clip, threading through the holes of the second clip, and hanging

The trial design and manufacture have been made for a transducer useful to measure the surface roughness. For this purpose a slender beam was set. This was soldered on a piano wire it the center of gravity as shown in Fig. 1., in order to give an oscillating motion to the stylus. The stylus was fixed on an end of the beam oscillating around the Piano wire with its natural circular frequency ω.When a test piece was put under the oscillating stylus and touched to it, the phase of the oscillation changed abruptly and led to the original phase by an amount of phase angle φ.Where φ was a function of the situation of the test piece. Then by measuring φ (Pulse Time Modulation) the situation of the test piece could be detected.

In the previous papers, the authors reported on the experiments of the coiled springs of steel wire under pulsating compressive load, and obtained the fatigue strength and the deformation due to fatigue. Through the tests, the authors found that the deformation limit diagram of miniature coiled spring differed from that of the ordinary round steel bar.In the same way as reported in the previous paper, the authors wanted to find the effect of three different conditions, that is, untreated, heat-treated and set conditions of the coiled compression springs of piano wire (PI). The authors also examined the deformation due to fatigue under various mean stresses of the coiled springs of piano wire, heat-treated and annealed at 800°C in vacuum, and compared this with the previous results.The results of these tests are as follows:1) The proportional limits, the fatigue limits and the creep limit of the three kinds of coild springs are as follows:The untreated spring showed the lowest values in all these, the heat-treated one was the second, and the set spring was the higher than the others.2) The residual shear strain of coiled springs under repeated compressive load was the largest in the pulsating test (τa=τm), but it decreased gradually as the mean stress increased up to τa/τm=0.6, and it appeared to increase more or less for the values of τa/τm smaller than 0.6.3) A stress amplitude τa at endurance limit decreased gradually as mean stress increases.4) τa in the fatigue creep limit diagram of the heat-treated spring kept approximately constant when τa/τm=1-0.6. While, τa began to decrease rapidly when mean stress increases beyond such a range, and the slope was about 60° to the abscissa τa=0.5) In the coiled spring, annealed in vacuum at 800°C, the deformation limit diagram kept almost horizontal when τa/τm=1-0.6 and began to decrease remarkably beyond such a range and the inclination was approximately 45° to the abscissa τa=0.6) It seems that the endurance limit diagram consists of an inclined line, and the fatigue creep limit diagram consists of a horizontal line (τa/τm=1-0.6) and an inclined line (τa/τm

To obtain the data for manufacturing and use of precise small ball bearings which are used for gyroscopes, high speed drilling spindles etc., the friction, at 8-100 r.p.m. under thrust load 0.1-2.0 kg, was measured by a measuring apparatus for small ball bearings, in which a piano wire was used as the tortion bar. It was made clear that there were some characteristics of them which were not known yet. If the accuracy and the surface finish of balls, races and cage are good, and if the cleaning of them and the protecting from dust are performed carefully, the frictional moment of small ball bearings will be very little, about 0.3 g-cm (thrust load 0.5 kg), 0.5 g-cm (thrust load 1.0 kg), and steady. Then such bearings will generally have good character at high speed.

A nylon bar, with the head notched to make easy adequete contact with the short process of the malleus, was used for an acoustic probe.The first part of this paper deals with the acoustic properties of the nylon probe in comparison with those of a piano wire probe and a silver wire probe. The following results are obtained :(1) Clinically the most suitable length of the nylon probe was 8cm.(2) The nylon probe proved to be capable of transmitting undistorted wave forms of test pure tones at the intensity level necessary for clinical measurment at the frequencies of 500, 1000, 2000 and 4000cps. Amplitude of the output through the nylon probe was a linear function of the intensity of input signals.(3) The intensity of the output through the nylon probe was kept almost constant to the test signals of 500, 1000, 2000 and 4000cps, when the fixing pressure of the nylon probe was in the range between 0.02gr and ibgr.(4) The nylon probe with a notched head showed the best fixation with the short process of the malleus in a corpse as compaired to the piano and silver wire probes.(5) When auditory threshold was measured at the short process of the malleus in a normal subject by the acoustic probe audiometry, the nylon probe showed more reliable values than the other probes.The second part deals with the clinical appli. cation of the acoustic probe audiometry with this nylon probe. A total of 82 ears with middle ear involvements were measured before surgical treatment. Auditory threshold test was carried out by fixing the notched head of the nylon probe at the short process of the malleus.The following results are obtained:(1) It was concluded that the ossicle hearing loss of less than 21db should be indicative of the existence of the normal ossicular chain, more than 25db indicative of interruption of the ossicular chain, whereas the ossicule hearing loss from 22db to 24db would indicate no definite pathological change in the ossicular chain.(2) Function of the ossicular chain might be represented by the value of auditory threshold measured by the nylone probe at the short process of the malleus, (3) It is not possible by the present test to detect the existence of the slightly interrupted ossicular chain, in which conductive connection was maintained to some degree by granulations.(4) The ossicle hearing loss was elevated with an increase in the degree of stapes fixation, however, very slight stapes fixation shown by slight negativity of Tsunoda's liquid conduction test could not be identified by the nylon probe audiometry.

A reciprocating wire saw for the cutting of brittle material, such as tooth enamel, is described. It cuts 50 μm thick sections of tooth enamel routinely. The sections have planoparallel smooth surfaces and further grinding or polishing is not necessary subsequent to the cutting if the sections are to be studied in the light microscope. The cuts left by the wire in the specimen have a width of 130 μm. Ordinary 100 μm. thick piano wire is used, and a slurry of 600 grit carborundum suspended in oil is applied as an abrasive. The cutting speed of the machine is only 0.1 mm/hr., as the feeding is controlled and slower than the speed of abrasion through the material to be sectioned. The stress on the specimen is thus very low, and results in whole undamaged sections.

This paper presents the results of compressive fatigue and creep tests on piano wire coiled spring, setting-treated at elevated temperature conditions. The specimen is treated for 4min at a temperature of 250°C under the compressive load of 40kg, for this condition gives the material the highest values of proportional limit and spring constant.The results obtained are as follows;(1) The fatigue limit of setting-treated spring is about 14% higher than the conventional bluing-treated one.(2) The value of deformation limit is nearly constant for the value of τa/τm from 0.6 to 1.0, while it becomes higher as the value of τa/τm becomes lower.

Although the polymer impregnated concrete (PIC) has such excellent characteristics as high strength, small water permeability, high corrosion resistance and no shrinkage, it has such weak points as low impact strength, no plastic range in strain and low toughness.In the present paper, the mechanical properties of fiber reinforced polymer impregnated concrete have been investigated by using several fibers, made of glass, polypropylene and metal, and MMA-and SM-monomers. The main results obtained are as follows:Among the five kinds of fiber examined, piano wire with 0.2mm diameter and 35mm length was most effective. The strengths of FPIC reinforced by the piano wire were 2003kg/cm2 for compressive, 536kg/cm2 for flexural, 195kg/cm2 for tensile, and 186kg/cm2 for Charpy's impact strength, whereas those of plain mortar cured in water were 593, 73, 36 and 8.7kg/cm2, respectively. And from the fact that the tensile maximum strain at the ultimate strength obtained in repeated bending test for PW-PIC beam 2500×10-6, it is deduced that FPIC-material has large toughness and has far more useful properties than PIC.

The mechanical properties of a low carbon steel have been very much improved by the help of rapid quenching, such as induction hardening. Low carbon steel has enough ductility to be worked in cold state even after being quenched. The mechanical properties are more improved by cold working after quenching than by quenching only. The author tried to get a high tension steel wire of low carbon content by making a practical application of a low carbon steel to give the excellent properties. The mechanical properties of a low carbon steel wire are very much affected by the factors, such as the temperature and speed of heating and cooling. In this paper the investigation of the effects of these factors on the mechanical properties of a low carbon steel wire is described. From the results the author comes to the conclusion that a high tension steel wire of low carbon content may be used in practice instead of a high carbon steel wire or piano wire.

It is well known that the fatigue failures of the valve springs in internal-combustion engines often give rise near both ends of them by surge in the springs in service, even though they have no defect in the material. To protect the strings against surge and to prevent fatigue failures the writer coated them with damping materials. The presence of damping causes the wave of torsional vibration of the wire of the spring to die out, and the high repeated shearing stresses in the coils of the spring are avoided. Three piano wire springs of almost the same dimensions A (uncoated), B (coated with lead) and C (coatde with copper) are compared in this experiment, and the following results are obtained. (1) Surge in the spring coated with lead is avoided and resonance in the spring coated with copper diminished considerably. (2) The ranges of repeated shearing stresses in the coated strings under repeated loading are notably smaller than those of uncoated springs and fatigue failures of springs may be avoidable by coating with damping materials. (3) As coating material, copper will stand for use in this rate of the angle of shear in the wire of the spring. (4) As for uncoated spring, maximum range of repeated shearing stress is measured about 5 times that of corresponding to the lift of cam. (5) By coating, a sping may be also protected against failures due to flaws on its surface.

The elongations and natural frequencies of conically‐shaped coil springs are derived theoretically for several dynamic boundary conditions. Frequencies are verified experimentally on nickel and piano wire springs, attesting the reliability of the computations.

In this paper, the writer reports the result of investigations of 82 paino wire concrete girders of 32 kinds which were carried out during the years from 1944 to 1948.By referring to literature on the subject published in foreign countries the writer has determined the subjects to be studied hereafter and has investigated experimentally the method of manufacturing piano wire concrete girders and their properties.From these experiments conclusions have been drawn on1) the girder manufacturing equipment and the essential points of its manufacturing, 2) required properties of concrete and piano wire which are to be used for piano wire concrete, 3) method of calculating the initial stress and cracking load, 4) effect of the contraction and creeping of concrete upon the girders, 5) bond strength between piano wire and concrete, 6) method of calculating the breaking load of the girders, 7) strengthening against breakage due to diagonal tension of the ribs, 8) standards for designing and manufacturing of the girders.For a piano wire concrete railway bridge of 2.75m span which is designed on the basis of the result of the writer's investigations, concrete of 46% and steel of 20% of an ordinary reinforced concrete bridge have been found sufficient.

In the deflection formula of a coiled spring δ=η8DPn/Gd, the different values of correcting factor η have been obtained by several authors for the small values of index D/d. Authors made experiments in order to determine a dependable value of η using steel and piano wire helical springs.In the above formula, d, D and G are the constants determined uniquely if the type and the dimension of the spring are given as to the material. The number of effective coils n is N-2, N being the total number of coils, and δ is the deflection of the helical spring obtained under the action of axial load P.Two correcting factors were considered as follows:ηt is the correcting factor for the case where the total deflection of the spring is considered. η1 is the correcting factor when only one coil in the middle section of the spring is considered in relation to deflection.We conducted some experiments on helical springs with various materials, types and dimensions.First, the modulus of rigidity G of the wire was measured. Then the relation between load and deflection were obtained for the whole coils of spring and for the middle one coil with no effect of the ends. The changes of the diameter D of the coil under various loads were also measured.The results obtained are as follows:(1) ηt is smaller than unity for small values of D/d, but it become larger than unity for larger values of D/d.(2) η1 is smaller than ηt by about 0.02. And they all tend to become constant for large values of D/d.(3) The manner in which the values of η1 change matches well with the result given by Gohner.(4) It is concluded that as the deflection factor for small helical springs, Gohner's one may be properly used.