AN IMPROVED METHOD OF MANUFACTURING SPRING WASHERS FOR SCREW BOLTS
Year: 1878

page_text: LETTERS PATENT to Carl Pieper, of Dresden and Berlin, for the Invention of
"AN IMPROVED METHOD OF MANUFACTURING SPRING WASHERS FOR SCREW
BOLTS." A communication from Theodor Springmann, Engineer, of Hagen,
Province of Westphalia, Prussia.
Sealed the 19th July 1878, and dated the 1st February 1878..
PROVISIONAL SPECIFICATION left by the said Carl Pieper at the Office of
the Commissioners of Patents on the 1st February 1878.
CARL PIEPER, of Dresden and Berlin. "AN IMPROVED METHOD OF MANUFAC
TURING SPRING WASHERS FOR SCREW BOLTS." A communication from Theodor
Springmann, Engineer, of Hagen, Province of Westphalia, Prussia.
This Invention relates to an improved method of manufacturing spring washers
for screw bolts. These washers consist of a piece of square or flat steel, bent into
a spiral-shaped ring, having its ends standing one above the other, and peripherically
at a slight distance from each other; they are principally applied to the bolts of
railway fish. plates for the purpose of preventing the nuts of such bolts from getting
loose.
Hitherto, washers of this kind have generally been made by cutting a bar of steel
of suitable section into pieces of the proper length, and subsequently bending them
into the desired shape.
According to the method forming the subject matter of this Specification, a bar
of steel of square or other suitable section, and of a length as it is manufactured, is,
at the onset, wound on a mandril, so as to form a spiral, having, by preference, its
windings close to each other. Into. this spiral, a cut is thereupon made either
parallel to its axis, or obliquely by means of a milling or a shaping machine, or
other suitable mechanical contrivance. The windings of the spiral are thereby all
detached from each other, each of them forming one of the desired washers.
}

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Carl Pieper in the Great Seal Patent Office on the 22nd July
1878.
CARL PIEPER, of Dresden, in the Kingdom of Saxony, Civil Engineer.
"AN
IMPROVED METHOD OF MANUFACTURING SPRING WASHERS FOR SCREW BOLTS."
(A communication from Theodor Springmann, of Hagen, Province of Westphalia,
Prussia, Engineer.)
This Invention relates to an improved method of manufacturing spring washers
for screw bolts, such as are applied principally to the bolts of railway fish plates,
for the purpose of preventing their nuts from becoming loose. These washers con-
sist of a piece of square or flat steel bent into a ring, which forms a single winding
of a spiral, so that its ends stand one above the other (or sideward of each other);
moreover, a small space is left between these ends in peripherical direction, as
shown by Fig. 1 of the annexed Sheet of Drawings.
When a washer of this description is placed between the nut of a bolt and a fish-
plate, &c., its edges a and a¹ will cut into these parts whenever there is a tendency
of the nut from turning backward, so that it is thereby prevented from becoming
loose. Of course, the washer when applied to a common bolt with right-hand
screw thread, must constitute a left-hand spiral, so that the nut upon being
tightened freely slides over the edge of the washer.
Hitherto, washers of this kind have generally been made by cutting a steel bar
of suitable section into pieces of proper length, and subsequently bending them into
the desired shape.
According to the method forming the subject matter of this Specification, however,
a bar of steel of square or other suitable section, and of a length as it is manufac-
tured on the rolling mill (or of any part of such length) is, at the onset, wound on a
mandril, so as to form a spiral, having its windings by preference close to each
other, as shown by Fig. 2. Into this spiral a cut is thereupon made lengthwise by
any suitable mechanical contrivance, whereby the windings of the spiral are all
detached from each other, each of them forming one of the described washers.
The cut which separates the windings of the spiral is by preference made
obliquely, as shown by Fig. 2, because the edges a and a' thus produced, are sharper
than when obtained by a cut parallel to the center line of the spiral. The said
cutting may be done on a milling, a shaping, or a planing machine, or by other
suitable mechanical means. The milling machine which the inventor prefers to use
for this purpose is shown by Fig. 3. The spiral d, after having been wound on the
mandril m, is secured by a nut n, whereupon it is placed with its mandril between
the centres of a saddle f, which, sliding on a suitable guide, may be moved forward
and backward by a hand crank g, with screw spindle (not shown in the Drawing),
in the same manner as a slide rest; h is a spur wheel fixed on an axle, revolving in
bearings attached to the saddle f. This wheel gears into a fixed rack i, and is con-
nected with a worm gearing into the worm wheel k.
When the crank g is turned, the saddle f with the spiral d will consequently be
moved lengthwise, while the latter is also slightly turned, thereby causing the cutter
e when revolving, to cut along the oblique line c, d. Of course, the cutter must be
placed at an angle corresponding to the line c, d. The cutter is driven by a strap
running on the pulley l.
When the inclined cut c, d, is made by means of a shaping or a planing machine,
a similar contrivance has to be applied for revolving the mandril slightly at every
stroke, which either the tool or the mandril itself makes, in case the cut is to be
. oblique.
The inventor, however, does not restrict himself to the application of any special
machine for the object in view, as many different known mechanical tools may be
adapted to the same purpose, either without any additional parts, or with such

page_text: slight alterations or attachments as will occur to any person of ordinary skill and
acquainted with mechanical engineering.
When a bar of steel is bent into a ring, its outside fibres are stretched, while the
inside ones are compressed; consequently, if the original section of the bar is a
square, its section after the bending will be a quadrangle, narrower on the outside
than the inside, see Fig. 4. The washer thus formed will therefore not bear equally
with its whole end surface respectively with its edges a, a', against the nut and the
fish plate, &c. For obviating this inaccuracy, the bar of steel may be rolled in a
shape which is the inverse of the one produced by the bending of a square rod, see
Fig. 5. When this rod is bent, its narrow side forming the interior of the ring, the
section will become square.
Having thus described the nature and object of this Invention, and the manner
in which it is to be or may be carried out in practice, as communicated to me by
the inventor, I claim as new and essential features of the same,-
1. The method of manufacturing spring washers for screw bolts, by winding a
rod of steel of any suitable section on a mandril, and thereupon making a cut
through all the windings by means of any suitable known mechanical tool, substan-
tially as and for the purpose described.
2. The manufacture of spring washers for screw bolts out of bars of steel of
quadrilateral section, the side intended for the interior of the washer being narrower
than the opposite side, as described and for the purpose set forth.
In witness whereof, I, the said Carl Pieper, have hereunto set my hand and
seal, this First day of July, in the year of our Lord One thousand eight
hundred and seventy-eight.
CARL PIEPER. (L.S.)