[0001] The present invention refers to a procedure for mounting elongated, principally cylindrical
elements such as expander pins in predrilled holes, for example.
[0002] Expander pins are resilient locking pins used for the demountable assembly of various
machine elements or mechanical components, e.g. for mounting wheels and the like on
shafts. The expanding capability is usually achieved by designing the expander pin
as a slotted, springy sleeve of alloy steel which is made resilient by heat treatment.
Expander pins are mounted in holes having a diameter less than that of the pin, with
the result that the pin is compressed when driven into the hole. Since the pin endeavours
to spring back to its normal expanding state it exerts sufficient pressure against
the inner surface of the hole to prevent axial movement.
[0003] Mounting of expander pins in holes is usually carried out manually by holding the
pin at the mouth of the hole and driving it into the hole with a hammer or other impact
tool. This form of mounting is time-consuming and troublesome, particularly in confined
spaces.
[0004] With the present invention a procedure and a tool has been achieved which has the
effect of substantially facilitating this mounting work. For this purpose the invention
has the characteristics specified in the following patent claims.
[0005] The invention will be described in greater detail in the following with reference
to the version shown in the drawing. The figure in the drawing shows a longitudinal
cross-section through a tool according to the invention.
[0006] The tool consists of a sleeve 1 which is provided with an axial through hole 2. A
striker 3 is so arranged in the hole 2 that it can move in an axial direction. The
end of striker 3 outside the sleeve 1 is designed as an impact head 4. The cylindrical
element which in the version shown consists of an expander pin 5 is arranged to be
accommodated in the hole 2 at the opposite end of the sleeve 1 to the aforementioned
impact head 4.
[0007] For retaining the expander pin 5 a chiefly radial hole 6 is provided in the sleeve
1 close to the end accommodating expander pin 5. Positioned in the aforementioned
hole is a loosely fitted locking pin 7 which rests against the expander pin. This
locking pin is retained and pressed resiliently against the expander pin 5 by a rubber
ring 8. The rubber ring 8 is fitted in an annular groove 9 in the surface of sleeve
1 adjacent to the radial hole 6. The resilience of rubber ring 8 is adapted so that
expander pin 5 is retained by the friction, even when the tool is pointed downward,
but not so that mounting of the pin is noticeably obstructed.
[0008] A corresponding locking device can be utilized to retain the striker 3 in sleeve
1. A return spring (not shown) can be arranged between the striker and the sleeve
to return the striker to the position of rest after each blow. Further, the aforementioned
striker can be provided with a means of restricting its outward movement.
[0009] The spring force applied to expander pin 5 from the side can naturally be arranged
in many ways and the version described above is only an example.
[0010] The tool can also be designed for easy connection to the pneumatic impact tool.
[0011] When using the tool described above for mounting an expander pin 5 in a predrilled
hole, the pin 5 is first fitted in the hole 2 in the sleeve 1. Locking pin 7 is pressed
against expander pin 5 by means of rubber ring 8. The sleeve 1 is then applied to
the predrilled hole and expander pin 5 is located in its mouth. Impact head 4 is subjected
to repeated blows with the effect that the striker 3 strikes expander pin 5 and drives
it into the hole.
1. A procedure for mounting elongated, principally cylindrical elements such as expander
pins (5) in predrilled holes, for example, characterized in that the element (5) before
mounting is fitted and resiliently retained in one end of an axial through hole (2)
in a sleeve (1) the other end of which is occupied by a striker (3) and said sleeve
(1) then being applied to an object with the element (5) against a predrilled hole,
following which the striker (3) is subjected to impacts so that it strikes the element
(5) and drives it into the aforementioned predrilled hole.
2. A procedure as in Claim I, characterized in that the sleeve (1) is fitted to a
pneumatic impact tool for achieving blows on the striker (3).
3. A tool for mounting elongated, principally cylindrical elements such as expander
pins (5) as in the procedure in Claim 1, characterized by a sleeve (1) provided with
an axial through hole (2) one end of which is arranged to accommodate a striker (3)
and the other end to accommodate and resiliently retain the aforementioned cylindrical
element (5).
4. A tool as in Claim 3, characterized in that the sleeve (1) close to the end accommodating
the element (5) is designed with a mainly radial hole (6) which extends inward to
the through hole (2) in the sleeve (1) in which hole a resilient device (7) is arranged
to press against the element (5) with a force so adapted that the element (5) is retained
even when the sleeve (1) is in a vertical position but so that movement of the element
is not noticeably prevented in connection with mounting.
5. A tool as in Claim 4, characterized by an annular groove (9) in the surface of
the sleeve (1) close to the radial hole (6) in which groove (9) a resilient ring (8)
is arranged to press a loosely fitted locking pin (7) present in the hole (6) against
the element (5) for the purpose of retaining it.
6. A tool as in Claim 5, characterized in that the resilient ring (6) is of rubber.
7. A tool as in any of Claims 3-6, characterized in that the striker (3) is provided
with a means of restricting its outward movement.
8. A tool as in Claim 7, characterized in that the striker (3) is designed with an
impact head (4) situated outside the hole (2) which serves as a stop to interrupt
the movement of the striker (3) into the sleeve (1).
9. A tool as in any of Claims 3-8, characterized in that a return spring is arranged
to counteract the movement of the striker (3) into the sleeve (1).
10. A tool as in any of Claims 3-9, characterized in that it is designed to be connected
to a pneumatic impact tool.