Handle Size Research Articles

Reduction of manufacturing lead-time through selection of machining rate and unit handling size

When parts are on the shop floor and in manufacture, they are either waiting for or are being attended by a machine or a material handling equipment. When several workstations are required to process a job, the machining and moving of the parts between the workstations can be very time consuming unless it is properly planned. When poorly planned, the processing and handling decision can significantly affect the length of time the job spends in the shop. In this paper, a methodology for planning the machining and the material handling activities for the manufacture of small to medium size batches in a job shop is presented. The model determines the machining rate at each workstation and the unit-load size to use in handling the batch through the production system in order to minimize the total production time. The procedure is easy to implement on a microcomputer for use in planning shop production activities.

Subjective Worker Assessments of Hand Tools Used in Automobile Assembly

A pilot study was conducted to determine if worker assessments of tool mass, grip force, handle size, and work location were related to corresponding tool and task variables. The workers (13 women and 10 men, who collectively used a total of 33 tools) were asked to rate the tool mass, grip force, handle size, and horizontal and vertical work locations of their own tools on continuous scales of 0 to 10. Significant findings included the following: (1) the weight of nearly all tools with 0.9 to 1.75 kg mass were rated “just right,” (2) the grip force required to use tools of 0.9 to 2.0 kg mass was rated as comfortable, (3) pistol-shaped tools were rated as more comfortable than right-angle tools, (4) workers wearing glovers gave tools a more comfortable grip force rating than workers with bare hands, (5) all tool sizes with handle circumferences less than 12 cm were rated as “just right,” (6) the most comfortable vertical location for using tools was between 102 and 153 cm, and (7) the most comfortable hori...

Grasp fatigue as a function of handle size and shape : Natarajan, J., Cochran, D.J., and Riley, M.W. In: Proceedings of the Human Factors Society 28th Annual Meeting ‘New Frontiers for Science and Technology’, San Antonio, Texas, 22–26 October 1984, Edited by M.J. Alluisi, S. De Groot and E.A. Alluisi. The Human Factors Society, Santa Monica, California, 1984, Vol 2,

Grasp fatigue as a function of handle size and shape : Natarajan, J., Cochran, D.J., and Riley, M.W. In: Proceedings of the Human Factors Society 28th Annual Meeting ‘New Frontiers for Science and Technology’, San Antonio, Texas, 22–26 October 1984, Edited by M.J. Alluisi, S. De Groot and E.A. Alluisi. The Human Factors Society, Santa Monica, California, 1984, Vol 2,

Ergcncmic Shovel Design

In spite of increased automation, there still is a need for ergonomically designed manual tools in the modern consumer and industrial environment. For example, many studies have examined the work physiology involved in shovelling but few have referred to the shovel design parameters needed to make the task more efficient. Thus the effects of such parameters as handle length and size and shape of blade, were examined on shovelling performance, energy expenditure and subjective ratings of perceived exertion. The results indicated the following recommendations in shovel design: a long tapered handle for efficient digging and shovelling, a square-point blade for shovelling, a round-point blade for digging, a large blade for low density materials and a small blade for high density materials.

Grasp Fatigue as a Function of Handle Size and Shape

This study investigated the influence of handle characteristics on fatigue of the gripping muscles while doing a slicing task as in using a knife in cutting meat. Subjects actually cut cylinders of modeling clay as a simulated meat-cutting task. Immediately after completing the cutting task the time to fatigue for the grasp muscles was estimated using the electromyographical technique developed by Petrofsky and Lind (1980). The handles evaluated were all rectangular ones with cross-sectional height to width ratios from 1:1.25 to 1:2. Each ratio was tested in four sizes. No significant differences in time to fatigue were found for the different handles. Time to fatigue was, however, significantly correlated with six anthropometric measures.

An Examination of the Speed of Manipulation of Various Sizes and Shapes of Handles

This research examined the effects of handle size and shape on two types of manual manipulation of handles. The first task evaluated was one in which the subject rotated a handle 180° in his/her hand one way, then reversed the rotation for 180° in the opposite direction. On this task smaller handles could be manipulated faster. Also triangular handles were significantly slower to manipulate than all other shapes tested except the square ones. The second task evaluated the speed of flipping a handle in the hand. For this task shape had no significant effect on the time but size did. Once again, the smaller handles could be manipulated quicker than the larger ones.

Sex differences in strength — some observations on their variability

One hundred and twelve datasets, which allowed a direct comparison of the strengths of men and women, were located in the published literature. For each of these, three indices of sex difference were calculated: the ratio of the mean female strength to the mean male (F/M), the proportion of the total variance in strength attributable to sex (R 2) and the “percentage of chance encounters between members of the opposite sex in which the female is stronger” (%CEFS). Sex difference was shown to be very variable, the values of these indices being both task and population specific. An experiment was conducted in which male and female subjects gripped and turned knurled cylindrical handles of 10, 30, 50 and 70 mm diameter. Maximum isometric torques were recorded. Sex differences became more pronounced as handle size increased. The optimal handle-size was 50 mm for both male and female subjects. Data concerning whole body exertion (Pheasant et al, 1982) were also analysed for sex differences. It was concluded that very similar tests of strength could exhibit very different levels of sex difference. The task or equipment designer should not make assumptions about sex differences in strength for a particular action, but should rely on empirical investigation.

An Evaluation of Handle Shapes and Sizes

In many industries there are numerous hand tools in use which vary considerably in handle size and shape with no apparent reasons. This research sought to investigate capabilities of males and females on two thrust maximum force tests, using various shapes and sizes of handles. To accentuate the characteristics of each size and shape, the force tests were conducted with the coefficient of friction between the hand and the handle surface reduced by the use of a disposable plastic glove and the application of a slippery film.

Three Studies of Parameters of Consumer Products: Pillow Softness, Cup Handle Size and Clothing Stripes

Three experimental studies of consumer products were conducted. A U-shaped relationship between pillow (dis)comfort and softness was found. Thermal discomfort and fatigue were found to be related to the width and the area of the coffee cup handle openings, respectively. While judgments of people's height and weight were affected by vertical and horizontal clothing stripes, judgmental accuracy was so high as to negate any practical benefits.

The determination of an optimum size cylindrical handle by use of electromyography.

An experiment was designed using muscle electromyography to determine if an optimum cylindrical handle size exists. The experiment had two phases. One phase was concerned with an experimental task ...