Engineering Drawings & Data

Part Numbers F-* (Molds and Liners Only)

Mergenthaler Linotype Company

image link-topic-sf0.jpg

1. Anatomy of a Linotype Mold

A Mergenthaler Linotype Company ("MLC") Mold part number such as F-2930 (Mold, Recessed, Job Shop Type, 10-14 point) designates an assembly, not an individual part. There is no single piece of metal which is an F-2930. It is necessary, therefore, to understand what the parts of a Mold are.

[click image to view larger]

image link-to-linotype-mold-main-components-RGB-sf0.jpg

The MLC Mold has two basic parts (three in older molds):

The Keeper, in turn, is attached to the Mold Body with (2) Keeper Screws. But in later practice [from the 1940s on?] the Keeper and Body were made as a single piece and called simply the Body.

[click image to view larger]

image link-to-linotype-mold-secondary-components-RGB-sf0.jpg

The Linotype mold also has several smaller parts. On the left and right are two upright posts which keep the Mold Cap in proper position relative to the Mold Body. These are called the Mold Cap Guides (Star Parts called them the Mold Posts).

(As an aside, MLC Drawing F-2930 contains this note: "Dress Mold Cap Guides so as to fit slightly loose in Cap, but not to exceed 0.00025." It is worth thinking about this statement. It means that to a Mergenthaler engineer, "slightly loose" meant a clearance of less than 25 hundred-thousandths of an inch.)

The two Mold Cap Guides were secured in place by two Mold Cap Guide Screws. (These are shown and identified in drawings such as Dwg. F-2930, but are not even shown in the generic mold drawing in Linotype Machine Principles.) Since the Mold Cap Guides were hand-dressed at the factory, they were not fully interchangeable parts. The Mold Cap, Mold Body, and two Mold Cap Guides (with their Mold Cap Guide Screws) had to be supplied as an assembly.

The mold would be used with various Mold Liners. The Parts Catalogs specified the Liners to be used with particular molds. Each Liner was designated by a single part number (example: F-517 Mold Liner (R.H.)), but this part number designated multiple similar Liners of varying dimensions. All R.H. Liners for a given Liner part number were the same width but varied in height (body size). L.H. Liners for a given Liner part number varied not only in height (body size) but in width (measure).

For certain styles of Mold, the Mold Body was also equipped with (2) Mold Liner Banking Screws.

[click image to view larger]

image link-to-linotype-mold-attaching-screws-RGB-sf0.jpg

The Mold assembly is attached to the Mold Disk by (4) Mold Fastening Screws. These are shown in the parts catalogs along with the Molds (e.g., on pp. 42-43 in Catalog No. 52).

The Mold Cap is tightened down with (3) screws:

These are really a part of the Mold Disk, not the Mold, but the parts catalogs show them along with the Molds.

The Mold is located on the Mold Disk by a Mold Disk Locking Stud. This is really a part of the Mold Disk, not the Mold, so it is shown in the parts catalogs along with the Mold Disks.

2. Finding the Parts of a Linotype Mold, For Service

How, though, do you find all of these parts? Let's work through a specific example: Mold F-2930 (Mold, Recessed, Job Shop Type, for "Blue Streak" Models 5 and 29 - 36). I'm using this example simply because it is the first one that I came across, not because this mold is in any way special.

If you just wished to acquire and install this mold, then you would look in Parts Catalog No. 52 ("Casting and Driving Mechanisms") for Blue Streak era machines. (At present I'm not addressing the question of using this Mold for pre-Blue Streak Model 5 machines.)

The Parts Catalog will tell you, first, that this is a Recessed, Job Shop Type Mold for a four-pocket Mold Disk. to be used for bodies in the range 10 to 14 points (p. 43). You would have ordered it by this part number (F-2930). This would get you the entire Mold (Body, Cap, Cap Guides (2), Cap Guide Screws (2) and Liner Banking Screws (2)), assembled. It would not get you Liners or the various attaching screws.

The Parts Catalog then specifies the part numbers for the two Liners to be used: F-872 (L.H.) and F-517 (R.H.) You would order (or find from your stock) these parts in the body size and (for the left Liner) measure you desire.

If your machine was in good shape, that would be it. But you might also find that you need to renew the various screws used to attach the mold.

Parts Catalog No. 52 lists only one kind of Mold Fastening Screw for Molds for all of the models it covers, so this must be it: F-65 Mold Fastening Screw.

Parts Catalog No. 52 lists the Mold Cap Clamping Screws twice, first on pp. 26-27 with the Mold Disk and again on pp. 42-43 with the Mold. (Actually, it also lists them separately for Six-Pocket Molds, but I'm ignoring that here.) Four screws are listed, short and long, regular and oversize:

(It is my assumption, although I do not know this from experience, that the oversize versions would be installed to compensate for wear.)

The Mold Disk Locking Stud is p/n F-1264 for all Molds in this catalog, but since it is properly a part of the Mold Disk rather than the Mold it can be ignored for this example.

3. Finding the Parts of a Linotype Mold, For Manufacturing

If instead you wished to manufacture or remanufacture any of these parts, you would have to go further. The general procedure is to identify by part number every part required (this can be complicated in the case of assemblies such as F-2930 because the parts catalogs do not list their constituent parts). Then consult the Dave and Beth Seat Archive of Mergenthaler and Star Parts Engineering Documentation (you're reading it now) to see if detailed manufacturing documents survive for the parts (checking first for MLC parts and then for compatible Star Parts parts). If/when this is unsuccessful, a new part would have to be reverse-engineered from an existing part.

Let's start with the attaching screws, because they're the easiest.

F-65 Mold Fastening Screw. This is called out in an abbreviated form in Catalog No. 52 as: 1/4" - 24 x .715" (p. 43). It is not further described in the "Tables of Screws, Dowels, Nuts, Etc." in the back of the book. of the Catalog (it is used in only this one application). The MLC detail drawing for it does not survive. However, the drawing for the Linotype Parts Company (Star Parts) equivalent, also (their) p/n F-65, does survive. This is important because the abbreviated specification in the MLC Parts Catalog does not give details about the head dimensions. For the Star Parts drawing, see F-65 in Linotype Parts Company / Star Parts Engineering Drawings & Data.

F-14 Mold Cap Clamping Screw, Short. This is called out in an abbreviated form in Catalog No. 52 as: 1/4" - 24 x 1/2" (p. 43). It is described in Table 3 (p. 156) in the "Tables of Screws, Dowels, Nuts, Etc." in the back of the book, but in this case the description there contains no new information (it's a set screw without a head). The MLC detail drawing does not survive. However, the detail drawing for the Linotype Parts Co. equivalent does survive (their p/n F-14 as well). See: Star Parts F-14

F-6679 Mold Cap Clamping Screw, Short (0.005 Oversize). This is called out in an abbreviated form in Catalog No. 52 as: 1/4" - 24 x 1/2" (.005 oversize) (p. 43). It is described in Table 3 (p. 156) in the "Tables of Screws, Dowels, Nuts, Etc." in the back of the book, but in this case the description there is not entirely accurate, since it does not indicate an oversize screw. The MLC detail drawing does survive: F-6679 (see below). In case you should think that these screws are "just hardware," note that this drawing for an apparently simple set screw went through four versions (that is, three revision levels) from 1937 to 1960. The Linotype Parts Co. detail drawing for their equivalent part, their p/n F-14-A, also survives. See: Star Parts F-14-A.

F-584 Mold Cap Clamping Screw, Long. This is called out in an abbreviated form in Catalog No. 52 as: 1/4" - 24 x 19/32" (p. 43). It is described in Table 3 (p. 156) in the "Tables of Screws, Dowels, Nuts, Etc." in the back of the book, but in this case the description there contains no new information. The MLC detail drawing does not survive. However, the detail drawing for the Linotype Parts Co. equivalent does survive (their p/n F-584 as well). See: Star Parts F-584

F-6678 Mold Cap Clamping Screw, Long (0.005 Oversize). This is called out in an abbreviated form in Catalog No. 52 as: 1/4" - 24 x 19/32" (.005 oversize) (p. 43). It is described in Table 3 (p. 156) in the "Tables of Screws, Dowels, Nuts, Etc." in the back of the book, but in this case the description there is not entirely accurate, since it does not indicate an oversize screw. The MLC detail drawing does survive: F-6678 (see below). The Linotype Parts Co. detail drawing for their equivalent part, their p/n F-584-A, also survives. See: Star Parts F-584.

Proceeding to the Mold Liners ...

F-872 Mold Liner (L.H.) This presents the first serious problem, because no detail drawings for it from either MLC or Star Parts survive. (More general Star Parts manufacturing information for liners does survive, however, and this may be of use. See Star Parts Mold Liners.) It must otherwise be reverse-engineered from existing physical parts.

F-517 Mold Liner (R.H.). The MLC drawing for this part does survive. See F-517, below.

Finally, the Mold itself...

F-2930, Mold, Recessed, Job Shop Type, 10-14pt. The assembly drawing for this Mold does survive. See F-2930, below. It identifies the following parts

(Note: The drawing for Star Parts F-3664-B survives, but it bears a note indicating that its '-B' suffix was adopted because it was not, in fact, interchangeable with the Linotype part.)

It illustrates, but does not identify by part number:

(Although their name is suggestive, I had to check an old Rich & McLean catalog to confirm the identify of these screws.)

The Changes on Drawing F-2930 indicate that the following parts were removed (at Revision Level 5, 1947-09-03):

(One of F-5232 or F-495 was certainly the Keeper.)

(Knowledge of these removed parts might be of interest if you were refurbishing an older version of this mold.)

Finally, Drawing F-2930 contains a note which says: "F-6383 Made from this part." I have not been able to locate F-6383 in the parts catalogs yet.

Summary:

The following parts must be reverse-engineered from surviving physical pieces; drawing survive for the rest:

4. Mold Assemblies

When possible, each part number will link to digitized surviving drawings or other reference material.

Note that Mold assemblies were fitted at the factory and were interchangeable only as an assembed unit. Individual parts within a Mold assembly are not necessarily interchangeable.

F-2930. Mold, Recessed, Job Shop Type, 10-14pt.

5. Mold Component Parts

When possible, each part number will link to digitized surviving drawings or other reference material.

When "F-*" parts are used only as Mold component parts (e.g., F-65 Mold Fastening Screw), they are shown here. When they are used in various locations (not just in Molds - e.g., F-14) they will be found in ../ Part Numbers F-* (Except Molds and Liners).

F-65 Mold Fastening Screw

F-495 [unknown]

F-496 Mold Keeper Screw

F-514 Mold Cap Guide [1, 2, 3, 4, 5, K, L, [etc.?]]

F-1110 Mold Liner Banking Screw

F-2929 Mold Cap (Recessed)

F-3373

F-3664 Mold Cap Guide

F-5232 [unknown]

F-8160 Mold Body

6. Liners

F-516. Mold Liner (L.H.), 4-pocket, 30 Em.

F-517. Mold Liner (R.H.), 4-pocket, 30 Em.

F-872 Mold Liner (L.H.), 4-pocket, 30 Em.

F-6787. Mold Liner (R.H.), 6-pocket, 30em

F-6788. Mold Liner (L.H.), 6-pocket, 30em

F-6855. Mold Liner (L.H.), 6-pocket, 30 Em.

F-7549. [probably a mold liner blank]

F-7553. [probably a mold liner blank]


Select Resolution: 0 [other resolutions temporarily disabled due to lack of disk space]