Improved Means for Guarding or Protecting Rotating or other Moving Parts of Machines to Prevent Accidents.
Year: 1898

page_text: Date of Application, 28th May, 1898
Complete Specification Left, 21st Jan., 1899-Accepted, 25th Feb., 1899
1
Improved Means for Guarding or Protecting Rotating or other
Moving Parts of Machines to Prevent Accidents.
I, HENRY JAMES PRYCE, of 54, Filey Avenue, Stoke Newington, London, N.,
Locomotive Superintendent, do hereby declare the nature of this invention to be
as follows:
The object of this invention is to prevent persons being struck and injured by
portions of machinery in motion.
For this purpose, according thereto, there are combined with a hinged or
pivoted cover or guard, a locking shaft or spindle able to be turned about its
axis to a certain extent (say through 90° or thereabout) and projections or stops
carried by or attached to the rotatory or moving part of the machine to be guarded,
the arrangement being such that when the cover is opened, the rotatory or moving
part of the machine will be locked, so that it cannot rotate or move, and when it
is free to rotate or move the cover or guard will necessarily be closed and locked.
In one arrangement, the locking shaft or spindle is furnished with projections
which, in angular positions of that shaft or spindle corresponding to the open
condition of the cover, will be in the path of the projections or stops of the rotatory
or moving part of the machine to be guarded or protected which will then be
uncovered and locked so that it cannot rotate and the locking shaft or spindle
and the (or a) hinge pin or equivalent of the cover are so recessed and relatively
arranged that the locking shaft or spindle cannot be turned so as to free the
rotatory or moving part of the machine without the closing and locking of the
cover.
The invention may be adapted and applied to machines of various kinds.
The following is an outline description of one arrangement as applied to a hollow
spindle stud lathe.
In such a lathe the hollow rotating spindle, open at the sides and through which
the metal bar to be operated upon is manipulated by the attendant, is a source of
danger to the operator.
Now according to this invention, a plain cover or guard which may be of metal
plate or wire work or other suitable material, is arranged so as to (when closed)
entirely cover the rotatory parts, being provided with a couple of sockets, to
which is rigidly fixed a pin about whose axis the cover can be turned as on a
hinge.
The central portion of this pin passes through a metal casting or lock-box bolted
to the lathe, in such wise as to form a rigid portion of the cover hinge.
A shoulder and washer and pin or equivalent arrangement hold the cover hinge
pin in a fixed position longitudinally with reference to the lock box.
The locking shaft or spindle is arranged transversely to the lathe bed and passes
under the centre of the lock box. At the near side of the machine is a handle by
which the locking spindle can be turned about its axis to a certain extent, say 90°.
To that part of the locking spindle that is under the rotatory part to be protected,

page_text: Referring to the accompanying illustrative drawings,
Fig. 1 shows, in front elevation, an arrangement according to this invention as
applied to a hollow spindle stud lathe. Fig. 2 shows a plan and Fig. 3 is a
view partly in cross section.
Fig. 4 illustrates partly in section and partly in elevation the interlocking of
the hinge pin and the locking spindle. Fig. 5 shows a detail of the cover hinge
and Fig. 6 is a transverse section of the lugs upon the locking shaft showing
the eccentric curvature of the ends whereby they serve to jam or wedge against the
two sides (forming stops) of the hollow spindle or mandrel.
In such a lathe the hollow rotating spindle a, open at the sides and through
which the metal bar to be operated upon is manipulated by the attendant, is a
source of danger to the operator.
Now according to this invention, a plain cover or guard A which may be of
metal plate or wire work or other suitable material, is arranged so as to (when
closed) entirely cover the rotatory parts, being provided with a couple of
sockets B B, to which is rigidly fixed a pin C about whose axis the cover can be
turned as on a hinge.
The central portion of this pin C passes through a metal casting or lock-box D
bolted to the lathe in suchwise as to form a rigid portion of the cover hinge.
Collars C¹and washers and pins or an equivalent arrangement hold the cover
hinge pin in a fixed position longitudinally with reference to the lock box.
The locking shaft or spindle E is arranged transversely to the lathe bed and
passes under the centre of the lock box. At the near side of the machine is a
handle E* by which the locking spindle can be turned about its axis to a certain
extent, say 90°. To that part of the locking spindle that is under the rotatory
spindle a, are attached two lugs F F which are formed with inclined or cam-like
surfaces F F eccentric to the locking spindle that can be raised into such a
position under the hollow rotating spindle a of the lathe as to jam or lock it and
prevent its rotation.
The further end of the locking shaft or spindle E passes under (but it might
pass over) the hinge pin C and so as to partly intersect it. In the hinge pin C
there is a groove or recess C2 having a part cylindrical form in which the locking
spindle fits, and there is a similar groove or recess E¹ in the locking shaft or
spindle, the axis of which groove passes directly under (but it might pass over)
the axis of the hinge pin C. When the angular positions of the locking shaft or
spindle E and hinge pin C are respectively such that the locking spindle E lies in
the transverse groove C2 of the hinge pin C, the hinge pin C cannot be rotated
and consequently the cover A which must then necessarily be closed cannot be
opened, and the position of the cam-like projections F on the locking shaft or
spindle will be such as to leave the hollow spindle a free to rotate.
If now the lathe be stopped and the handle E* turned so as to cause the locking
shaft or spindle E to leave the transverse groove C2 of the hinge pin C, this turning
will effect the locking of the hollow spindle a of the lathe, at the same time freeing
the hinge pin C so that the cover A can be opened.
The description above given will suffice without further explanation to enable
the invention to be readily applied to other machines wherein it is desired to
guard or protect moving parts to prevent accidents.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed. I declare that what
I claim is:-
:—
1. For guarding or protecting a rotating or other moving part of a machine to
prevent accidents, the combination of a hinged or pivoted cover or guard, a
locking shaft or spindle able to be turned about its axis, and projections or stops
(or a stop) carried by, formed on or attached to the rotatory or moving part to be
guarded, the arrangement being such that, when the cover is opened, the rotatory
or moving part of the machine will be locked, so that it cannot rotate or move, and