Chapter II: Preface (2)

Exact register and accurate trimming can be secured only by working from the same edges of the paper at every operation and the edges must be straight and squarely cut. When the edges are thus trimmed they should be marked with a red crayon, or in some similar manner, in order to be readily identified at each handling.

A pile may be tested for squareness by jogging it in the cutter table against both the back gage and the side gage, if the machine gages are themselves in perfect adjustment. If it is difficult to see whether the sides of the pile are close against the gages at all points, narrow strips of paper put between the pile and gages will show whether the pile touches the gages uniformly.

When cutting lithographed work or similar close-register printing, where large sheets are apt to come with an irregular edge, a small wooden block against the back gage or the side gage at points on the sheet where the original register guides of the press were placed, will usually insure cutting on an accurate line with the printing. In this manner the same points of contact as were used in the press feeding may be secured.

To cut a pile of paper in half, fold over the top sheet and fold at the middle, carefully matching the edges. Crease this fold distinctly and use the crease as a guide when the sheet is opened out and laid on the pile. To cut into thirds or fifths it is better to measure the sheet exactly with a rule and make clear pencil marks at the points of cutting.

Hand-made papers have rough, uneven edges which are thicker than the rest of the sheet and, therefore, require particular care in jogging and clamping. They should be handled in small piles.

Gummed and varnished papers require special care even when perfectly dry, but more so in a moist atmosphere. Varnished stock if it is very dry may nick the knife, and a clean oily (but not too oily) swab run over the bevel of the knife before the cut will make a smoother, safer cut. It is not well to use soap on the knife, especially on lithographic work.

Freshly printed work which tends to offset on the next sheet may be cut where necessary by placing strips of reglet or thick card around the margin close to the line of the proposed cut, so as to keep the pressure of the clamp off the printed matter.

Tissue paper requires to be firmly clamped to cut accurately. A clamping motion that will first exert a gentle pressure to squeeze the air out between the sheets and pack the pile down evenly all over and then apply a powerful pressure before the knife strikes the pile, gives the best results.

Accuracy is required in manifold duplicate work, where absolute register must be made, to secure the proper location of dollars in dollars columns and cents in cents columns. The ruling and printing both depend entirely on the square and accurate cutting of the stock to secure proper register.

The cutting of waxed and oiled manifold stock, if carefully jogged up, is not difficult with the newer types of clamping mechanism, especially on that type of cutting machine where the pressure of the automatic clamp is applied at first gently and then with maximum pressure, similar to the hand-clamp.

_To Cut a Pile into Strips of Equal Width_

This is sometimes required to be done for a large quantity of stock and it is desirable to do it with economy of time and labor. The obvious method is to first trim one edge of the stock, then set the back gage to the required width and jog the pile up to it for each cut. This method is usually accurate but requires a great deal of handling of the stock--almost three times as much as is necessary by some other methods.

The following methods require the pile of paper to be first trimmed with a true edge in order to jog it against the back gage, and also with a true edge on the opposite or front side.

1. Make a mark or place a thin paper sticker on the top surface of the front table the exact distance in front of the cutting edge of the knife to correspond with the required width of the strip. Place the pile of paper on the back table with a trimmed edge against the back gage. Move the gage forward so that the front edge of the pile comes to the mark on the front table. Make the cut. Repeat this until the pile is cut up. This requires only one jogging of the pile into place.

2. Same as the method just described, except that a small hinged metal gage is used instead of a mark on the table. This requires a special device. The front flange of this device or gage may be slotted and fastened to the table by a thumbscrew. The vertical angle part must be hinged to the part fixed to the table so that it can be swung upward and back far enough to leave the cut pile room to move forward on the table when the knife passes down through the pile.

3. Use a hand automatic spacing device, gage screw movement.

4. Use a template placed on top of the pile. Run the clamp down to the pile, place a card or fiber template on top of the pile in front of the clamp. Draw the pile forward until this front edge coincides with the front edge of the template. Make the cut and repeat the operation until the pile is cut up.

5. Draw the front edge of the pile forward to dimension on the regular graduated rule set in the front table.

6. Draw the pile forward the distance desired by reading the steel tape scale overhead, or the dial, or the graduation on the gage movement wheel.

7. Use a hand automatic spacing device, chain movement.

_To Cut a Pile Rectangular_

To trim a pile with perfectly true corners first jog its straightest edge against the back gage, and make the first trim. Then jog this cut edge against the back gage and make the second trim, keeping the pile away from the side gage. This trimmed edge should be exactly parallel with the edge trimmed first. Then jog either of these cut edges against the side gage, and push gently (but do not jog) to the back gage, for distance. This cut will be at exact right angles to the first and second. Turn the pile and make the last cut with the trimmed edge against the back gage keeping the pile away from the side gage.

Do not try to jog a pile against both side gage and back gage at the same time, for, although these are at right angles, the attempt to force a pile against both will slue the pile.

Turn the pile on the table with the greatest care; do not lift it between cuts or jog it vertically. To test a pile for rectangularity, turn part of it one-half way around and match the edges.

_To Square a Pile_

_First_--Set the back gage about one-eighth inch further from the cutting edge of the knife than the desired dimension of the square. The extra distance the back gage is set beyond the dimension of the square will depend upon the amount necessary to trim it to a true, clean edge.

_Second_--Jog an uncut edge of the pile against the back gage and make a clean trim.

_Third_--Jog this clean trim against the side gage and just "feel" the back gage for distance. This trim is at right angles to the first.

_Fourth_--Now draw the back gage up to the exact dimension of the square desired.

_Fifth_--Jog either of the clean trimmed edges against the back gage (keep the pile away from the side gage). This trims three sides.

_Sixth_--Jog the pile against the back gage and trim the remaining uncut edge, keeping the pile away from the side gage. This completes the square.

To test a pile for squareness, turn part of the pile one quarter way around and match the edges.

_To Cut Unusual Shapes_

Any odd shapes having straight lines may be cut by the following method: Make a sample of the shape and size required; then take a piece of No. 70 strawboard a little larger than the pattern. The board must be squared up, and the odd-shaped card laid on it; then put the two pieces under the clamp and adjust the strawboard against the back gage and the sample card even with the clamp in front; then run the clamp down and draw a pencil line around the sample card on the strawboard. A piece of wood can then be glued on to the strawboard along the pencil line at the back and another at the end. If a bunch of cards is laid into this box gage and the board pushed up against the back gage of the machine, a narrow strip of wood or board must be glued on the clamp right over the card, so that a pressure may be secured on the stock. This clamp-stick must, of course, fit into the box gage, so that it will take up the difference in thickness between the pile of stock and the height of the box gage. These gages may be made by means of a square and a pair of dividers, as well as in the machine.

Celluloid may be cut into narrow strips by using the method described above. A sharp knife and rubber bands are all that are necessary.

_Trimming Books_

A common error made by printers is to make up forms nearly the full measurement of the leaf, thereby leaving the binder very little trim margin. A standing rule of every printing and binding establishment should be to allow one-eighth of an inch trim margin for the fore-edge, head, and tail of all stitched tablets and quarter-bound cut-flush books. All sewed books should have three-sixteenths of an inch for the fore-edge, and one-eighth of an inch for the head and tail trim margins. The trimming of letter-press work should be standardized, so that paper-covered books are trimmed a trifle larger to permit a retrim when books are returned for a substantial cover. To illustrate this, a sheet 24 x 38 inches made up into thirty-two-page signatures, when folded, is 6 x 9-1/2 inches. The paper-covered books should be trimmed 5-7/8 x 9-1/8 inches; one-eighth of an inch is trimmed off the head, the balance off the tail, while the fore-edge has one-eighth of an inch trim. These books, when returned for permanent covers, as they frequently are, have one-sixteenth of an inch trimmed off the head and tail; and one-eighth of an inch off the fore-edge. This gives the standard book size, 5-3/4 x 9 inches for the bound volume.

When the entire edition is to be bound with a permanent cover, provision is made for three-sixteenths of an inch trim at the head. This enables the printer to standardize forms without varying the head margins, and gives the binder sufficient margin to trim inaccurately folded sheets.

To trim books on a cutting machine, take as many as will make a pile about three inches high, and jog at the head and back. Set the back gage the exact size to which the book is to be trimmed; put the books in the machine with the head against the side and the back against the back gage. Run down the clamp, provided the machine has a hand clamp; an automatic or self-clamp requires nothing more than to pull the lever. When the cut has been made and the machine stops, remove the books and put to one side. Repeat this operation until all books are trimmed on the fore-edge and lay aside in piles with the backs out.

To trim the heads and tails, fillers must be made to take up the thickness of the back. Cut strips of straw or binders' board about four inches wide; glue them together; fan out and press. Put the books in the machine with the heads against the back gage and the trimmed fore-edges against the side; then lay the board filler on top in such a way that the fanned-out ends are sufficiently away from the back to permit an even pressure of the clamp on the books. Pull the lever, and repeat the operation for subsequent books. The filler can be glued to the clamp and the books put directly under it.

For the head, the gage is set forward and the trimmed tail is placed against the back and side gage. The board filler is placed on top in the same manner as above described and the operation continued. On thin books the board filler may be dispensed with by reversing the backs of the books alternately, so as to distribute the thickness of the back on both sides of the pile.

If there are two splits in the back gage, _i.e._, if it is a three-part back gage, set the center for trimming the fore-edge, the left for trimming the tail, and the right end for the head. This, however, should be done only when the quantity to be trimmed justifies it. When the back gage is set, tighten the thumbscrew with the hand. To guard against the marking of the book by the pressure of the clamp, cut a piece of binders' board somewhat larger than the width of the clamp face and glue it on the clamp.

Waste leaves should be placed on the top and bottom of enameled or glazed stock to keep it clean.

To trim quarter-bound cut-flush tablets or pads which are bound two or more on a sheet, as in the case of receipts, trim the fore-edges, cut all the tails alike, then the heads. The knife should cut against the back. In making up books to be bound two or more on, one-fourth of an inch trim must be provided for, to clear the bevel caused by the knife. This is provided for if books are made up with one-eighth of an inch trim for the head and tail. Thick books can be bound two or more on until the stitching is completed. Then cut apart and proceed with the rest of the binding in the regular way.

Blank books are trimmed so that the standard sizes are reduced one-fourth of an inch for the length and three-sixteenths of an inch for the width. The paper for a medium book is 18 x 23 inches; when folded, 11-1/2 x 18 inches. If such standard sizes are adopted the work of forwarding is greatly facilitated, as cases and boards can be made in advance without fear of the books being trimmed too large.

In trimming spring-back account-books, sewed straight or on guards, the fore-ends are trimmed, then forwarded until the books are in straps. Sharp knives are indispensable in trimming books which are concave on the fore-edge. Deep rounds should be filled in with waste paper to prevent the top sections and the back from breaking. Board fillers are always laid on top and the book placed so that the knife will cut against the back.

Brochures with extended cover should have the stock first cut to size of cover before printing, and sufficient extra stock allowed for an all-round trim of the inset after, especially at the fore-edge where after folding in sections the inner sheets are apt to bulge forward. The printer should know how much will be taken off in the after trim to enable him to allow uniform widths of margin. After a job is bound, the cutting machine cannot remedy any defect of edges.

_Paper Cuttings and Waste_

Cuttings and waste may be disposed of by throwing them into a large bag attached to or placed near the machine. When filled, this can be taken away and another substituted. Throwing waste on the floor should not be tolerated. It is untidy, costs time and labor to gather up, and is dangerous.

A light box on wheels is also a good plan for caring for waste of this kind. In some places where there is a great deal of trimming, a chute in the floor next to the machine provides a convenient method of disposing of waste from a number of machines. This chute leads into a large bin or baling machine below, from which the material is carted away.

The worth of a paper-cutter operator can be measured by an examination of the waste cuttings. A careless operator can waste a large sum of money in a year. Many persons make a good living from the waste paper of large printing and binding plants by buying it at a nominal price and selling it again at a considerable advance.

There is unavoidable waste, of course, but there is often a great deal of unnecessary trimming. When the necessary trimming runs up into hundreds and thousands of pounds, as it does in all large plants, it is worthy of notice, especially when it is realized that this waste has been paid for at the same rate per pound as the stock that is actually used. Some printers and binders sort and bale their waste and dispose of it so as to make a considerable saving, but few understand how a little care and system can be made to return a good profit.

There is another waste, sometimes far greater in amount, caused by the careless cutting of stock. A thoughtless operator will often try to save ten minutes by hasty calculation and then waste stock through inaccurate cutting that costs several dollars.

In some binderies the operator is instructed to sort his trimmings according to the kind of stock; that is, clean white edge trimmings kept by themselves are worth more than when mixed with miscellaneous colored trimmings. By having two or more bins at hand into which these different kinds can be thrown as they come from the knife the sorting can be done without extra handling.

An intelligent inspection, segregation and saving of the waste cuttings will well repay the effort. The larger pieces of waste can be kept for pads or other use. White stock should be kept separate from colored and where the quantity will warrant the cost, all waste should be baled in a baling press.

_Depreciation of a Paper-Cutting Machine_

Deterioration takes place in a paper-cutting machine chiefly in the knife, friction clutch, driving-shaft bearings, knife-bar guide ways, and knife pull-down connection. Depreciation in the entire machine occurs rapidly when it is not kept oiled, adjusted, and clean. Neglected bearings which run dry are ruined in a short time. The times for the daily oilings and weekly cleaning and polishing should be fixed and faithfully attended to.

On modern machines the worn knife and the friction-clutch bearings may be easily replaced or repaired. Knife-bar guide ways and the guide slot for the back gage are made with adjustments for taking up wear, for which the maker will give correct instructions on request. The knife-bar pull-down connections are not so easily corrected for wear, and the simpler and more direct these connections are, and the fewer slots and rolls, pins, etc., the better. The general design of the machine also affects its value, especially if it is not adapted for the addition of improvements or attachments for increasing its production.

The depreciation that comes from natural evolution due to the constant effort by machine makers to render their product more efficient, and the impossibility of attaching to the older machines new and improved devices, is more serious for two reasons: _first_, that it is apt to be overlooked by the owner; _second_, because of the greater cost of operating the machine, as compared to one of a later and improved design with attachments especially adapted to the particular work in each case, which in some cases permit three, four, five, and six times as much work being produced as can be obtained on a machine not so equipped.

A well designed and built paper-cutting machine will last with care nearly half a century. The prudent manager, however, will find he is obliged to discard most of the machines of various kinds in his plant in much less than twenty years in order to keep pace with the newer shops starting with the advantage of later-designed machines.

SUGGESTIONS TO STUDENTS AND INSTRUCTORS

The following questions, based on the contents of this pamphlet, are intended to serve (1) as a guide to the study of the text, (2) as an aid to the student in putting the information contained into definite statements without actually memorizing the text, (3) as a means of securing from the student a reproduction of the information in his own words.

A careful following of the questions by the reader will insure full acquaintance with every part of the text, avoiding the accidental omission of what might be of value. These primers are so condensed that nothing should be omitted.

In teaching from these books it is very important that these questions and such others as may occur to the teacher should be made the basis of frequent written work, and of final examinations.

The importance of written work cannot be overstated. It not only assures knowledge of material but the power to express that knowledge correctly and in good form.

If this written work can be submitted to the teacher in printed form it will be doubly useful.

REVIEW QUESTIONS

1. For what is a paper cutting machine used?

2. How does it increase printing output?

3. What is its great importance?

4. What were the first methods of cutting paper, or its earlier
substitutes?

5. How were piles of paper first cut?

6. How was the process improved?

7. Describe the development of cutting machines down to Samuel R.
Brown's invention.

8. Describe that invention.

9. Give the lines of evolution of the cutting machine.

10. What are the characteristics of the best paper-cutting machines?

11. Describe a plough and press cutter.

12. Describe a card cutter.

13. Describe a hand lever cutter.

14. What are the differences between hand and power cutters, and what are the advantages of the latter?

15. Describe two forms of hand-clamp power cutters.

16. What do automatic clamp machines do?

17. How is an automatic power cutter operated?

18. How is continuous running effected?

19. For what are vertical stroke machines used?

20. What results from the great power needed to operate cutting machines?

21. Give some idea of the amount of power needed for these machines.

22. What is the most important part of the machine and why?

23. How do these parts vary?

24. How can you judge the temper of a knife?

25. How can you tell whether a knife has a correct face?

26. How should you hone a knife?

27. What is the rule for the length of the bevel on knives?

28. How is this rule modified by stock?

29. What can you say of the face of the knife?

30. What is desirable in the thickness of the knife?

31. What precaution should be taken as to the setting of the knife?

32. What should you look at if the work is not cut true?

33. Tell all you can about grinding knives.

34. Tell all you can about the use of the hone.

35. What causes are liable to prevent the proper seating of the knife, and what is the result of improper seating?

36. How can the best knives be obtained, and why?

37. How is the paper held in place?

38. Describe the mechanism used.

39. What is the relation of the power exerted by the operator to the power obtained at the clamp?

40. What was the characteristic of the first automatic clamp cutting machines, and how have they been improved?

41. Describe the cutting stick and its substitutes.

42. What is the back gage, and how does it work?

43. Mention some improvements which have been made on the back gage.

44. How is the distance of the back gage read in hand-operated gages?

45. Describe an appliance for reading the movement of a back gage operated by power.

46. What contrivances are in use for cutting at any time duplicates of a given job?

47. How is the back gage locked?

48. How may piles of different widths be cut at the same time?

49. What device is used on the larger sizes of cutting machines?

50. What special devices have been applied to the back gage to increase production?

51. How is the width of the cut measured?

52. Describe some modern patented spacing devices, and tell what they accomplish.

53. What is a clamp face?

54. What is a snake gage?

55. What special contrivance is used for large pamphlets, etc., and for what purpose?

56. What safety devices are required by some states?

57. What five methods of applying power are in use?

58. Give the four great rules for the care of the machines.

59. What advice is given about adjustment, stroke of the knife, pressure of the clamp, use of oil?

60. What is the right time to jog stock, and why?

61. How should you oil the parts above the table?

62. How can you make the stock handle easier?

63. How can you keep stock clean?

64. What wrenches should be used and why?

65. What things should be done periodically?

66. What does a cutter operator need to work with, and how should he care for them?

67. What can you say about belts?

68. How should you care for waste, especially when oily?

69. How should you use oil?

70. What is the best sort of oil?

71. Upon what three things does the character of the cutting depend, and why?

72. How may accidents be prevented?

73. How is time consumed in cutting stock?

74. How can labor saving be accomplished?

75. What safety rule applies to cutting?

76. Why is a sharp knife an economy?

77. How can you keep the machine clean and bright?

78. How should you care for the clamp strap ways?

79. What care should be taken of the friction brake band?

80. How can you prevent rust?

81. How can you keep the gage screw wheel graduation true?

82. Give the four devices which safeguard the knife.

83. What are the things to study in handling stock?

84. What can you say about each of these things?

85. What are the causes of inaccurate cutting when the machine is in good order?

86. What care should be taken in piling sheets?

87. What precaution is necessary in cutting printed sheets?

88. What is a mill edge and what does it require?

89. How can exact register and accurate trimming be secured?

90. How may a pile be tested for squareness?

91. What device is used in cutting lithographed work and the like?

92. How can you cut stock in certain fixed portions?

93. What peculiarity have hand-made papers?

94. What precautions are needed with gummed and varnished stock?

95. What precaution is desirable in the cutting of freshly printed stock?

96. Give several methods of cutting a pile into strips of equal width.

97. How can you cut a pile rectangular?

98. What are the processes for squaring a pile?

99. How can you test a pile for squareness?

100. What care has to be used in cutting tissue paper?

101. How can waxed and oiled manifold stock be managed?

102. What additional margins should be left on book pages for trimming after they are bound?

103. Describe the operation of trimming books on a cutting machine.

104. How are quarter bound cut-flush pads or tablets trimmed?

105. How are blank books trimmed?

106. How are spring-back account books trimmed?

107. How are brochures with extended covers trimmed?

108. What should be done with cuttings and waste?

109. By what can you measure the worth of a paper-cutter operator?

110. How would you apply the test?

111. How can waste be prevented, or waste paper utilized?

112. Where does a paper-cutting machine naturally show special wear?

113. What other consideration affects the value of a machine?

114. How does the invention of improved machines affect the value of old-style machines?

115. How long should a good paper cutter last?

GLOSSARY OF TERMS USED

AUTOMATIC CLAMPING--Means that the clamp descends upon any height pile and produces approximately the same clamping pressure for all heights and all kinds of material. Among the methods for producing this pressure for automatic clamping are devices which employ friction discs turned only one way by ratchets which produce the maximum pressure with the least expenditure of power; friction discs or friction plungers worked forward and reverse; surfaces sometimes combined with wedge-shaped ways for producing a resultant pressure from the knife; weights, oil and hydraulic and air plungers; springs, climbing gears and weights, etc.

BACK GAGE--A movable device against which the paper is placed for measuring the size of the sheet to be cut.

BRAKE, AUTOMATIC FRICTION--Generally a band with a lining which grips automatically the outside of a wheel fastened to the driving gear and stops it promptly after every cut when the knife rises to the top.

CHUG--The action of the knife that results from lost motion in the parts connecting the knife-bar to the parts that operate it. "Chug" is caused, first, by the looseness of fitting necessary to permit the parts to operate without heating, and second, by wear of these parts. "Chug" dulls knives and spoils stock and makes expense for grinding, sharpening, and knife replacement.

CLAMP--The part that presses the work firmly on the table to hold it while being cut.

CLAMP, ONE PIECE--Means a single casting used both for marking (or gaging) the stock where the knife is going to cut and also for pressing the pile to hold it.

CLAMP DWELL, LONG--Means that the clamp is held down a little longer upon the pile after the knife has cut, so as to allow the knife to rise to a safe height before the clamp is released. This prevents the knife rippling up the sheets on the return motion and disturbing the pile.

CLAMP FACE--A removable flat steel plate fastened underneath across the clamp fingers to prevent the indenting of soft stock.

CLAMPING, AUTOMATIC PRESSURE ADJUSTMENT--A device for varying the holding pressure easily and instantly for different kinds of work.

CLUTCH, FRICTION DRIVING--An improvement over the jaw clutch, because instead of starting the machine with a jar, it permits gradual engagement of the power.

COUNTERBALANCE WEIGHT FOR KNIFE-BAR--A safety device which, through constant and dependable action of gravity, always tends to keep the knife from dropping.

CUTTING STICKS--A wood or soft metal piece inserted in the table, on which the knife edge strikes; in shape usually square, but sometimes round and rotatable by hand or power to present fresh surfaces after a number of cuts.

DOUBLE-SHEAR STROKE--Means there are three motions taking place at the same time; first, the downward motion through the pile; second, the single "shear" motion across the face of the pile; and third, the double-shear motion which means that the cutting edge starts to cut higher at one side than the other and by rocking approximates parallel when it reaches the bottom of the cut at the table. The double-shear cuts more like a pair of scissors, the knife edge entering each sheet at its side and gradually cutting across it. Its advantages are less power required to cut, less strain on the machine and the knife, a more perfectly cut edge and a smoother face to the pile. See Fig. 10, Page 18.

DUPLICATING DEVICES, AUTOMATIC--See "Spacing Devices."

GAGE MOVEMENT, CABLE--A steel wire cable wound around a drum which when revolved pulls the back gage forward or backward.

GAGE MOVEMENT, CHAIN--A connection for operating the back gage to and fro; principally used with automatic spacing devices.

GAGE MOVEMENT, POWER--A friction drive variable speed connection from the main driving shaft to move the back gage forward and backward.

GAGE MOVEMENT, SCREW AND HAND WHEEL--This is used on the simpler, cheaper styles of cutting machine devices. It is slower than the cable device, but more reliable.

GAGE MOVEMENT, AUTOMATIC SPACING DEVICE--This quickly moves the back gage and the pile forward a given distance without measuring for each cut, thus largely increasing production.

GREASE CUPS--Receptacles with a screw top containing lubricating grease, which is forced a little at a time upon the bearing when the screw top is turned, or which starts to melt and flow if the bearing warms.

GROOVED TABLE--Means slight rounded depressions lengthwise in the back table in which the back gage fingers travel, extending slightly below the table surface to catch the lowest sheets and prevent them from wedging under the back gage.

HAND CLAMPING WHEEL--Is generally connected to the clamp by a worm and gears (or directly by a screw). A force of one pound exerted on its rim holds the work with about one hundred and fifty pounds pressure and correspondingly more for each additional pound.

INDICATOR--Generally a steel ribbon ruled to sixteenths of an inch, reading the distance from the front face of the back gage to the cutting edge of the knife.

INTERLOCKING CLAMP AND BACK GAGE (also called fingered clamp and fingered back gage)--Recesses in the clamp permit projections on the back gage to push the work farther forward than if both clamp and back gage were solid and the clamp of sufficient width to hold the stock firmly.

JOG--To jog a pile against the gage is to strike it with a blow just sufficient to bring every sheet in the pile so that it touches the gage and in the same relative location with each other if all the margins are uniform.

KNIFE--A piece of tempered tool steel about one-half the width and thickness of the whole blade, forged into a piece of less expensive soft steel, in which holes can be drilled more easily for the bolts that hold it to the knife bar.

KNIFE ADJUSTMENT--Devices for lowering the knife-bar to compensate for the wear of the knife and for tilting it in case the knife edge is ground out of level.

KNIFE-BAR--A rigid carrier for the knife. The best style takes the down thrust and side thrust of the knife directly upon a solid shoulder planed in it, instead of the knife back abutting against the points of adjusting screws.

KNIFE-BAR MOTION--A mechanical way of imitating the action of a draw shave in pulling down the knife. The nearer it is to the hand method, the more simple and successful it is. Rods connected to each end of the knife-bar and pulled down by simple cranks at each end approach nearest to the method of human hands.

LIFT--The pile of paper or other stock cut and handled at one time.

MARKER--A part of the clamp on some machines, separate from the pressing part, that may be pulled down by a treadle to show where the knife is going to cut.

MOTOR BRACKET--A support attached to one side or top of the cutter to which the electric driving motor is firmly bolted.

OIL BOXES--Channels containing oily waste which allows the oil to seep slowly upon the bearing.

OIL CUPS--An oil feeding device requiring careful attention.

PLAIN CLAMP AND BACK GAGE--The under face of the clamp is a solid broad surface without any recesses; consequently the back gage has no projections but is simply a solid smooth front.

PILOT CLAMPING WHEEL--A wheel with handles projecting from the rim to give a firmer grasp.

POWER ATTACHMENTS--For hand-power cutters. These may be put only on machines designed and built originally for them.

SAFETY BOLT (LOCK STOP)--A steel bar which must be unlocked each time before the machine can make a cut.

SIDE GAGES--Flat guides bolted to each side of the table, front and back, accurately set at right angles to the knife and the table, against which the stock may be set to cut square.

SINGLE-SHEAR STROKE--The stroke of a knife which has a side-wise motion at the same time that it descends, with its edge always parallel with the table top. The single-shear cuts the entire width of each sheet at the same time all through the pile.

SOLID KNOCKER FOR THROW-OUT--This is a part solidly fastened to the shaft (or gear) making one revolution for each cut of the knife and that throws the clutch out positively and puts on the brake throwing in the safety bolt after every stroke of the knife.

SPACING DEVICES, AUTOMATIC--See "Gage Movement, Automatic Spacing Device."

STARTING BAR--A rod extending clear across the front of the larger size of the machines to start and stop the machines.

STARTING LEVERS--Preferably two, one at each side, on medium size machines, to start and stop the machines.

TABLE--A slab of metal upon which the stock is laid and handled for cutting.

TABLE, FRONT SIDE EXTENSIONS--Wings bolted on the front table upon which work may be handled before and after cut without having to turn around.

TOGGLING CRANK--A device on hand-lever cutters that increases the power as knife goes down and eliminates jumping on the lever to get the knife down through the lower part of the cut.

TREADLE, FOOT (for clamping)--A convenience which leaves the operator's two hands free to handle the work while locating the line of the cut by pulling down the clamp with foot treadle.

VERTICAL STROKE--An attachment for shear or double-shear stroke cutting machines which brings the knife down vertically, instead of side-ways. It is used with knives of a special shape to cut irregular or fancy edges or to pink cloth samples. See Fig. 9, page 17.

TYPOGRAPHIC TECHNICAL SERIES FOR APPRENTICES

The following list of publications, comprising the TYPOGRAPHIC TECHNICAL SERIES FOR APPRENTICES, has been prepared under the supervision of the Committee on Education of the United Typothetae of America for use in trade classes, in courses of printing instruction, and by individuals.

Each publication has been compiled by a competent author or group of authors, and carefully edited, the purpose being to provide the printers of the United States--employers, journeymen, and apprentices--with a comprehensive series of handy and inexpensive compendiums of reliable, up-to-date information upon the various branches and specialties of the printing craft, all arranged in orderly fashion for progressive study.

The publications of the series are of uniform size, 5 x 8 inches. Their general make-up, in typography, illustrations, etc., has been, as far as practicable, kept in harmony throughout. A brief synopsis of the particular contents and other chief features of each volume will be found under each title in the following list.

Each topic is treated in a concise manner, the aim being to embody in each publication as completely as possible all the rudimentary information and essential facts necessary to an understanding of the subject. Care has been taken to make all statements accurate and clear, with the purpose of bringing essential information within the understanding of beginners in the different fields of study. Wherever practicable, simple and well-defined drawings and illustrations have been used to assist in giving additional clearness to the text.

In order that the pamphlets may be of the greatest possible help for use in trade-school classes and for self-instruction, each title is accompanied by a list of Review Questions covering essential items of the subject matter. A short Glossary of technical terms belonging to the subject or department treated is also added to many of the books.

These are the Official Text-books of the United Typothetae of America.

Address all orders and inquiries to COMMITTEE ON EDUCATION, UNITED TYPOTHETAE OF AMERICA, CHICAGO, ILLINOIS, U.S.A.

TYPOGRAPHIC TECHNICAL SERIES _for_ APPRENTICES