US1410010A

US1410010A - Mechanism for converting rotary into reciprocatory motion

Info

Publication number: US1410010A
Application number: US501987A
Authority: US
Inventors: Goldschmidt Rudolf
Original assignee: DET TEKNISKE FORSOGSAKTIESELSK
Current assignee: DET TEKNISKE FORSOGSAKTIESELSK; DET TEKNISKE FORSOGSAKTIESELSKAB
Priority date: 1921-09-20
Filing date: 1921-09-20
Publication date: 1922-03-21
Anticipated expiration: 1939-03-21

Description

R. GOLDSCHMIDTa IIIIECHANISIVI FOB CONVERTING ROTARY INTO RECIPROCATORY MOTION.

APPLICATION FILED SEPT.20, 1921.

LMQQJIQID Fab embed. 2119 1922,

FIG.

2 b'HhETS-SHEET 1-- R. GOLDSCHMIDT MECHANISM FOR CONVERTING ROTARY INTO RECIPROCATORY MOTION,

APPLICATION FILED sEPT.20.1021. lAlQGlQL Patented Mar. 2L 1922..

2 SHlzETSSHEET 2- UNITED STATES PATENT OFFICE.

I RUDOLF GQLDSCHMIDT, OF BERLIN, GERMANY, ASSIGNOR TO DET TEKNISKE FOBSGS- AKTIESELSKAJB, OF ORDRUP GHARLOTTENLUND, DENMARK, A COMPANY OF DEN- MARK.

MECEANISM FOR CONVERTING ROTARY INTO RECIPROCATORY MOTION.

Patented Mar. 21, 1922.

Application flied September 20, 1921. Serial No. 501,987.

' a citizen of Germany, and a resident of Berlin, Germany, have invented certain new and useful Mechanism for Converting Rotary into Reciprocatory Motion, of which the following is a specification.

This invention relates to improvements in mechanism for converting rotary into reciprocatory motion, applicable to reciprocatory or percussive tools or other reciproc'atory apparatus.

According to the present invention, the member which is reciprocated by means of a centrifugal Weight or Weights or the journal of said weights is capable of movement at right angles to the path of reciprocation or spirally and a spring or othermeans is provided for yielding restraining this movement.

The object of the present improvements is to mitigate or eliminate the vibrations due to the lateral forces set up in the reciprocatory member by the rotation of the centrifugal weights and also to reduce the consequent friction on the lateral guides of the reciprocatory member.

The invention is hereinafter described with reference to the accompanying explanatory drawings whereon:

Fig. 1 is a sectional view of a percussive hand tool in its preferred form.

Fig. 2 is a diagrammatic viewillustrating a modified form of my invention.

Figs. 3 and 4: are side and cross-sectional views respectively of mechanism illustrating how the lateral forces are set up.

Fig. 5 is a longitudinal section and Fig. (i an end view showing the application of my improvements to such mechanism.

Fig. 7 is a plan view (partly in section) of the mechanism shown in Fig. 5.

Referring firstly to Fig. 2 of the drawings, the mechanism shown therein is of the type described in my prior patent specification (Serial No. 436206) and comprises a member a having a journal 0 for the arm 8 of a centrifugal weight 0 and capable of sliding between guides f and spring buffers 01 and e. In this arrangement, the member is reciprocated b a force H and subject to a lateral force which gives rise to friction on the guides f and vibration of the mechanism. In order to overcome this friction and vibration, the journal 0 may be carried by a blocka movable in relation to the member a in a direction at right angles to the path of reciprocation. The-force V is then absorbed in displacing the block a transversely and the movement of the latter may be limited by springs g.

Figs. 3 and at illustrate an arrangement similar to that of Fig. 2 of my aforesaid prior patent specification in which, although the two centrifugal weights 0' and 0 are so arranged that the forces V are balanced, a turning moment M is set up ?which changes in direction at every half revolution. In order to minimize the effect of this turning moment, the member a may be so mounted that it can follow the turning moment M by turning on its own axis. In this manner unilateral pressure on the guides f is over-1- come. The turning movement of the memf ber a is preferably yieldingly restrained'by a spring.

Such an arrangement is illustrated in Figs. 5, 6, and 7 wherein the member a is supported by spindles Z) and b the spindle Z) sliding in a bearing f and the spindle 6 being keyed to a bush h which is slidable and rotatable in a bearing 7, the bush h projecting through the bearing so as to receive a gear wheel r slidably keyed thereto by means of a key r and key way r in the bush h. The bush It carries a bevel wheel 7:; gearing with a pair of bevel wheels $3 each rigidly connected to the arm 8 of the centrifugal weights 0 and 0 and rotatable on a crosspin p. Between the bearing f and the crosspin p is fitted a helical spring a fixed at its end to the bearing f at n and at its other end at n? to the cross-pin p.

The member a is thus capable not only of reciprocation under the influence of the rotating weights 0 and 0 but also of rotation as indicated by the double arrows I in Fig. 6 under the influence of the turning moments. These oscillations are resiliently absorbed or reduced by the spring n which also serves to eliminate any slight variations in the angular velocity of the bush h, due to irregularity in the power supply. Also, when the mechanism is applied to a hammer or ram, a pause occurs in the movement of the member a during the impact, this pause reacting on the mechanism. The reaction in such case is also absorbed by the sprmg n,

whilst the gear wheels 70 roll upon the ear] of which is mounted a gear wheel 11 meshing with a gear wheel 12. The wheel 12 is loose upon a shaft 13 journalled in the casing and drives the shaft 13 through a coil spring 14 which thus absorbs irregularities due to variation of the electric power supply. The shaft 13 extends into a hollow bush 15 which is splined thereon and which carries a pinion 16 and an extension 17. The latter supports a bush 18 and a pair of arms or tubes 19 on which are rotatably mounted a pair of eccentric weights 20 carrying gear teeth 21 which mesh with the pinion 16. The outer extremities of the arms 19 support rings or eyes 22 formed upon or carried by a rlng or collar 23 which is a loose fit in the casing'8. The collar 23 is shown cut away to allow for the rotation of the weights 20. A spring 24 is interposed between the collar 23 and a web 25 which extends across the casing and supports the journal of the shaft 13. The spring 24 is fixed at one end to the web 25 and at the other end to the collar 23. Centered at one end by the extension 17 and slidably supported at its other end in a sleeve 26 is a tup or hammer 27 adapted to strike againsta button 28 in the centre of a flexible diaphragm 29. The sleeve 26 has a disc-shaped extension 26* which serves to clamp the diaphragm 29 upon a tool holder 30 which encases a spring 31 hearing against the button 28. The tool holder 30 has a central hollow guide 32 for the tool 33. The guide 32 also serves to center a sleeve or bush 34 carried by the button 28. A nose 35 having a threaded portion 36 screwed into the head of the tool holder 30 serves as an abutment for-a shoulder 37 on the tool 33, so that by adjustment of the nose 35, the distance between the inner end of the tool 33 and the button 28 can be varied, thus varying the length of stroke of the tool. The tool holder 30 is shown threaded into the end of the casing 8 at 38, so that it may be removed together with the diaphragm 29 and sleeve 26, whereupon the reciprocatory mechanism is readily accessible.

The hand grip 9 is shown fitted with a prlng thumb piece 39, whose spring 40 ugal weight pivoted presses against a slide block 41 carrying a plug or pin 42, which when inwardly pressed, establishes electrical contact between two spring contacts 43 and thus closes the motor circuit.

Claims- 1. Mechanism for converting rotary into reciprocatory motion com rising a recipio catory mem er, a journa carried thereby and movable in a direction at right angles to the path of reciprocation, a centrifugal weight mounted on said journal, means for rotating said weight and means whereby said journal is ieldingly restrained in its movement at rig t angles to the path of reciprocation.

2. Mechanism for converting rotary into reciprocatory motion, comprising a reciprocatory member capable of spiral motion around its axis of reciprocation, a centrifthereto and means for yieldingly restraining said spiral motion.

3. Mechanism as specified in claim 2 in Y which the means for restraining spiral motion consists of a helical spring fixed at one endand secured at its other end to the reciprocatory member.

4. In a reciprocatory tool, a'reciprocatory tup, a centrifugal Weight pivotally mounted on the tup, means for rotating said weight, a casing for the tup and a spring connected at one end to the casing and at the other end. to the tup.

5. In a reciprocatory tool, a casing, a drivlug shaft journalled in said casing, means for driving said shaft, a gear wheel splined on said shaft, arms journalled on an extension of said gear wheel, eccentric weights rotatable on said arms and geared to said gear wheel, a tup supported by said arms and slidable in a journal in sai casing and means for yieldingly restraining spiral motion of the parts about said extension.

6. A tool as specified in claim 5 in which the restraining means comprises a collar said arms and a spiral spring fixed at one end to said collar and at the other end to said casing.

7. A tool as specified in claim 5 having a nflotgr within the casing, for the driving s a;

8. A tool as specified in claim 5 having an electric motor within the casing, a handle for the casing and a push switch on the handle for controlling said motor.

9. A tool as specified in claim 5 having a tool socket on the end of the casing, a flexible diaphragm between said tool socket and the tup and a spring for pressing said diaphragm towards the tup.

In testimony whereof I hereunto ailix my signature.

RUDOLF GOLDSCHMIDT.