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The purpose of this paper is to investigate the process of jamming of the hollow parts on the shaft and to derive a mathematical model for jamming in an assembly process.

The mathematical model for jamming of parts on the shaft in an assembly process is based on the sizes, geometry, angular declination of part and shaft axes, and the frictional factor.

The equation for angular positional tolerance of coaxial parts and shafts, based on their geometry and sizes and leading to jamming, was derived.

A mathematical model of parts jamming on the shaft is developed for assembly mechanisms. This research does not consider flexible deformations of components in assembly mechanisms, which results in the axis concentricity of part and shaft in the assembly process.

The results presented in the form of angular positional tolerance for coaxial parts and shafts based on their geometry and sizes make it possible to avoid the jamming of the parts. The results allow for formulating the angular positional tolerance of the assembly mechanisms that clamp the parts.

The proposed method for calculating the angular positional tolerance of coaxial parts and shafts for the assembly process should allow for increasing the reliability of the assembly process in the manufacturing industry.

The purpose of this paper is to investigate theoretically the process of jamming in the peg‐hole type parts and to derive a mathematical model of jamming.

The mathematical model of the jamming of the peg‐hole type parts in assembly process was performed and its boundary conditions, which lead to jamming, defined.

The equation of the critical angles of declination for the peg, which leads to the peg‐hole jam, was derived. The boundary condition of the angles of declination and the depth of the peg insertion into the hole were defined.

A mathematical model is developed for rigid parts with a hole and for the peg clamped in the rigid assembly mechanisms. The research has not considered flexible deformations and stiffness of the assembly mechanisms, which result in the peg's declination in the assembly process.

The results are represented in the form of the peg's critical angles of declination and critical depth of insertion into the hole, which leads to jamming of the peg‐hole type parts to be assembled. On the basis of the obtained results, it is possible to formulate the tolerances of the declination angles for the assembly mechanisms, which clamp the peg‐type parts.

The proposed method calculating the critical angles of the peg's declination and critical depth of the peg's insertion into the hole for assembly of the peg‐hole type parts, enables one to increase the reliability of the assembly process in the manufacturing industry.

Stiffness adjusting ability is essential for soft robotic arms to perform complex tasks. A soft state enables dexterous operation and safe interaction, while a rigid state enables large force output or heavy weight carrying. However, making a compact integration of soft actuators with powerful stiffness adjusting mechanisms is challenging. This study aims to develop a piston-like particle jamming mechanism for enhanced stiffness adjustment of a soft robotic arm.

The arm has two pairs of differential tendons for spatial bending, and a jamming core consists of four jamming units with particles sealed inside braided tubes for stiffness adjustment. The jamming core is pushed and pulled smoothly along the tendons by a piston, which is then driven by a motor and a ball screw mechanism.

The tip displacement of the arm under 150 N jamming force and no more than 0.3 kg load is minimal. The maximum stiffening ratio measured in the experiment under 150 N jamming force is up to 6–25 depends on the bending direction and added load of the arm, which is superior to most of the vacuum powered jamming method.

The proposed robotic arm makes an innovative compact integration of tendon-driven robotic arm and motor-driven piston-like particle jamming mechanism. The jamming force is much larger compared to conventional vacuum-powered systems and results in a superior stiffening ability.

In a previous article we had occasion to refer to and to condemn the standards for jams, jellies and marmalade which had been arrived at as the result of a conference which had taken place during the year 1930 between the Jam Panel of the Food Manufacturers' Federation and certain members of the Society of Public Analysts and other Analytical Chemists. There is another point in connection with these standards which we think might have received the attention of this Conference. At the present time everyone is being exhorted to buy British goods on the grounds, it may be supposed, that such purchases are patriotic in character and good for trade. But to speak quite frankly, if these jams are to be taken as a fair example of British skill and enterprise, the legend “Buy British” leaves us cold. What, then, is a British jam? Is there such a thing? If by the term we mean a jam made of sound British grown fruit which gives the name to the jam mixed with an equal weight of sugar, it would seem to be a rarity. Some fruits we cannot grow. Hence Scotch marmalade is a fair enough term to use, assuming of course that the orange is of the right sort and in the right quantity. The same thing applies of course to apricot jam. The greater number of our best known jams are made from fruit that, whatever may be its origin, can be grown here and grown better here than elsewhere— strawberry, raspberry, plum, gooseberry. We say unhesitatingly that there is no need under any circumstances to buy the pulp of these fruits or the fruits themselves abroad when it is of immediate interest to the health and pocket of the consumer, the prosperity of the home fruit grower and ultimately to the trade itself to buy them at home. In a report issued in 1927 on Fruit Marketing in England and Wales issued by the Board of Agriculture it is stated that the manufacture of jam is the “backbone” of the fruit‐growing industry. It is further stated that 90 per cent. of the home grown raspberry crop, 60 per cent. of the strawberry and 40 per cent. of the plum are or were at that time purchased by the manufacturers of jam. We say “at that time” because the figures in all probability relate to the conditions in force up to 1926, and that year it seems began to mark an increase in the amount of fruit pulp imported from foreign countries. The fact that pulp was being imported in large amount previous to that year is noted in the report whose title is given above, 90 per cent. of the home grown raspberry crop available for the manufacture of jam is used, but what is to be thought of the figure given for plums? In connection with this we need only quote the remarks of Lieut.‐Col. Ruggles Brise which he made during the debate in the House of Commons on the terms of the Resolution.

To investigate how jamming of particles in a solder paste varies as a function of the gap through which the particles flow, and to correlate this with skipping defects during the printing process.

Solder pastes with particle sizes of types 2, 3, 4 and 5 were sheared between the parallel plates of a rheometer. Jamming events that cause the solder particles to be forced against each other were detected by monitoring the electrical current flowing between the plates under a bias of 1.0 V or less. Solder paste printing trials were conducted with the same pastes, and solder paste skipping monitored.

Jamming was detected when the ratio of plate gap to largest particle diameter is reduced to a value between 3.8 and 5.0. Decreasing the gap further results in increased jamming. A strong correlation between levels of skipping and jamming was found.

More extensive printing trials are required before rheometric jamming detection can be used to predict printing performance.

The common rule of thumb used in solder paste printing that the aperture width should be no smaller than 4‐5 particle diameters is justified.

This paper presents a new technique for detecting jamming events which are too brief to be detected using normal rheometric techniques, but which have long been thought to be responsible for stochastic skipping defects during printing. Evidence supporting the link between jamming and this type of defect is presented.

The milk supply of our country, in one form or another, has been the subject of discussion year after year at Congress meetings. Its importance is an admitted fact, but, notwithstanding, I again venture to call attention to the matter. On this occasion, however, I do not propose to touch much of the ground already covered by former papers, but to consider the results of experiments and observations made while dealing with milk supply under the Sale of Food and Drugs Acts. For many years dairy regulations have been in force throughout the country which deal with the construction of floors and walls, and with lighting and ventilation. The owners of dairy farms in many parts of Scotland have spent large sums of money in improving their farms. Indeed, some enthusiasts have gone the length of introducing a system of heating and mechanical means of ventilation. It is only reasonable to pause and consider the practical results of these improvements, and to discover who are reaping the benefits from a milk supply standpoint. Do the owners of dairy farms receive anything like a fair return for their capital outlay? No. It is a well‐known fact that rents are on the down grade. Is the farmer of to‐day in a better financial position than formerly? No. He will tell you that the working of a “modern dairy” is more expensive than in the old steading, and that there is less flow of milk from the cows in the large airy byre than in the small old “biggin.” The price of milk is considerably less than it was fifteen or twenty years ago. At that time it ranged from 10d. to 1s. per gallon, and it is well known to you that hundreds of gallons of milk are now sent into our large cities for at least a distance of 100 miles, carriage paid, at 7½d. per gallon. In some cases the price is 9d. per gallon during the winter and 7½d. in summer. A farmer I know has a contract with a dairyman to supply him with 20 gallons of sweet milk, 16 gallons of skim milk, and 4 gallons of cream every day at an average rate of 7½d. per gallon all the year round. I have proved, by having test samples taken of the sweet milk, that it contains an average fat of 4.89 per cent. in 16 gallons. Neither the owner nor occupier of the farm can be any better off so long as such small prices prevail. Does the profit then come to the consumer? It does not.

In his letter which appeared in the April number of this Journal, Mr. Edward Hinks, B.Sc., F.I.C., criticises our remarks on the jam standards set up by the Food Manufacturers Federation in conjunction with the Society of Public Analysts and Other Analytical Chemists, and the tone of his letter seems to indicate that he has not appreciated the position we take with regard to standards, a position which is consistent with the policy we have always followed, namely, to deprecate the making of a standard which lowers or tends to lower the quality of any product, and especially to deprecate it when the label does not adequately disclose any additions which have been made to the article in question. Whatever Dr. Johnson may have thought about jam in 1755, his definition undoubtedly agrees with what the British public considers jam should be to‐day, and that is, that it should be made from the fruit from which the jam derives its name and sugar—and nothing else.— It is hardly necessary to add that beet sugar—sucrose derived from beet, could be used as well as cane sugar —sucrose derived from cane.—Any extraneous addition should be properly described on the label. With regard to the standards which have been put forward by the Jam Section of the Food Manufacturers Federation in consort with the Society of Public Analysts and Other Analytical Chemists, we certainly take exception to the proportion of fruit permitted, which in many cases is so low, that pectin, derived from apple or some other source, has to be added to make a jam of saleable consistency. This addition means a shorter boil and a lower fruit content, a distinct gain to the manufacturer in the cheapening of the production of his article. How it can be contended that the public will get a good article if the manufacturers make jam according to these standards we cannot understand. In our opinion the public will get a poor jam, and may and probably will, in fact purchase a product containing added fruit juices, citric and tartaric acids and foreign colouring matter, and further they will have no opportunity of learning that these additions have been made, because no declaration need be made on the label. On the contrary such jam may be labelled “Full Fruit Standard.” Why no disclosure is to be made of such additions to First Quality Jam while the disclosure of the presence of added fruit juice is insisted on in Second Quality Jam—which doubtless no manufacturer will be too anxious to make —is difficult to understand. It appears to us that the Federation has had its own way too much in the fixing of these standards and that in its anxiety to reach agreement the Society of Public Analysts and Other Analytical Chemists, or its representative committee has allowed itself to be led much too easily. Again the country of origin of the fruit may perhaps not be regarded as relevant but what an excellent thing it would have been to have insisted that first quality jam should be made from home‐grown fruit. It is true that analysis cannot prove the country of origin of the fruit any more than, with our present knowledge, it can show that any jam contains for instance 42 per cent. of a particular fruit, but on the other hand there are methods of ascertaining whether imported fruit is used in a jam factory. As to the spirit in which we approach this matter we have felt it our duty to criticise, somewhat severely, standards which as it seems to us, give to a certain class of manufacturer permission to do the very thing he wants to do in the way of making extraneous additions to jams without imposing the necessity of declaration on the label. Such standards accordingly afford practically no protection to the unfortunate public, but tend ultimately to lower the general quality of the jam made in this country.

This case provides insights about the importance of market research, market segmentation, distribution, product positioning, branding and advertising for a small but growing enterprise. This case provides insights into nuances about organizing and running a family-owned small business –Bhuira Jams has to objectively decide on its way-forward which can be a pure social enterprise or a pure commercial enterprise. This case provides understanding regarding the differences between the two models in terms of funding, accounting, legal, marketing and operational aspects.

In January 2017, Linnet Mushran had just won an award from the PHD Chamber of Commerce for her work in generating local employment for rural women in the village Bhuira, Himachal Pradesh, India. This award did make her feel happy. However, more than happiness, it got her thinking as to how would Bhuira Jams – the child born out of her passion for mountains and out of the desire to do something good survive in the coming years? Bhuira Jams was never designed like a formal business. Being a family run socially relevant business, Bhuira Jams faces the challenge of operational efficiency, along with an uphill task in marketing and distribution. Almost 35 per cent of its sales comes from Fabindia, which re-sells the Bhuira products under the Fabindia label. Thus, currently there is very little focus and expenditure in Bhuira on marketing and distribution. Another challenge faced by Bhuira Jams is driven by the health and lifestyle changes occurring in the Indian society. Consumer preferences are shifting towards low fat diets, and there is growing Americanization of the Indian society. This can be a double whammy for Bhuira’s main product line of preserves, which are high on calorie and are traditionally British.

Bhuira Jams conceptually is close to a family owned business due to the involvement of husband, daughter-in-law and son-in-law of Linnet. Thus, this case provides insights into nuances about organizing and running a family owned small business.

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CSS 11: Strategy