US3900974A

US3900974A - Portable surface-treating machine with improved platen-mounting construction

Info

Publication number: US3900974A
Application number: US442518A
Authority: US
Inventors: Jr Elmer C Klebe; Timothy J Looper
Original assignee: Singer Co
Current assignee: Ryobi Motor Products Corp
Priority date: 1974-02-14
Filing date: 1974-02-14
Publication date: 1975-08-26
Anticipated expiration: 1992-08-26
Also published as: CA1008671A

Abstract

An electrically-driven portable surface-treating machine having the motor and means driven thereby for oscillating a platen mounted within a clam shell housing. The oscillatable platen is connected to the housing through securement to a plurality of resilient posts connected to the housing. The posts are formed with flanges which are retained within recesses formed transversely in the housing and there are pairs of such posts at respective ends of the housing, a flange of each pair of posts being in abutting relationship.

Description

1 51 Aug. 26, 1975 United States Patent 1191 Klebe, Jr. et al.

[ PORTABLE SURFACE-TREATING MACHINE WITH IMPROVED PLATEN-MOUNTING CONSTRUCTION P i Exa iner-Donald G. Kelly Inventors: Elmer C. Klebe, Jr., Easley;

Attorney, Agent, or FirmMarshall J. Breen; Chester Timothy Looper, PiCkBnsy both f A. Williams, J11; Harold Weinstein SC.

ABSTRACT [73] Assignee: The Singer Company, New York,

An electrically-driven portable surface-treating ma- Filedi 1974 chine having the motor and means driven thereby for oscillating a platen mounted within a clam shell hous- 21 Appl. No.: 442,518

ing. The oscillatable platen is connected to the housing through securement to a plurality of resilient posts connected to the housing. The posts are formed with flanges which are retained within recesses formed 4 m0 3 m2 m I m m2" .l C St Um NH 55 Field Of Search-m 51/170 170 170 R transversely inf-the housing and there are pairs of such posts at respective ends of the housing, a flange of each pair of posts being in abutting relationship.

[56] References Cited UNITED STATES PATENTS 2,885,833 5 1959 51 170 MT 2 Clams 5 Drawmg Flgures PATENTED IQYB PORTABLE SURFACE-TREATING MACHINE WITH IMPROVED PLATEN-MOUNTING CONSTRUCTION BACKGROUND OF THE INVENTION It has been knwon heretofore to provide electricallydriven portable surface-treating machines such as sanders, polishers, buffers and the like with an oscillatable platen which is connected to the housing of the machine through securement to a plurality of resilient posts. Generally, pairs of such posts are positioned at opposed ends of the machine. The housing for such ma chines is frequently formed by a pair of complementary mating halves which are detachably secured along the longitudinal axis of the machine. Such housings, are known in the art as being of the clam shell type.

In order to impart the desired motion of the platen of such a machine as hereinbefore referred to it has been found desirable to connect the platen to a plurality of such resilient posts. However, to insure proper initial seating and avoid subsequent accidental displacement of the posts during normal operation of the machine, as well as to facilitate integration of the platen subassembly with the housing, various expedients have been adopted. One such prior construction utilizes a specially deformed back plate for the platen subassembly in combination with a bracket in order to locate the base flanges of the resilient posts with respect to the platen and permanently affix them in place. A spacer member is used at the top of adjacent posts which posts also act in concert with a specially designed groove and annular tongue in the housing for positioning of the upper segments of the posts. Thus, there has been a long standing need for improving the constructional arrangement by which the platen is secured to the housing through the use of the resilient posts.

SUMMARY OF THE INVENTION It is one object of the invention to provide a electrically driven portable surface-treating machine in which an oscillatable platen is supported by a plurality of resilient posts without any substantial risk of unintended post displacement and without requiring the use of a separate spacer element, which overcomes the prior art deficiencies and is simple, economical and reliable.

It is another object of the invention to provide an electrically driven portable orbital sander having an oscillatable platen s ubassembly which can more easily be mounted to a clam shell housing and which uses posts which are self locking in pairs within the clam shell housing.

Other objects and advantages of the invention will become readily apparent upon reading the following description of the invention.

The present invention thus, provides in an electrically-driven portable surface-treating machine in which the motor and means driven thereby for oscillating a platen are mounted within a longitudinally divided clam shell housing and said platen is connected to said housing by being secured to a plurality of resilient posts connected to said housing, the improvement which comprises:

a. transversely, extending recesses formed in the ends of one of said platen and housing;

b. a plurality of resilient posts each of which i vided at one end thereof with a flange dimensioned t fit within said recesses to secure said one end of th post therewithin;

c. said posts being provided at the other end thereof with a locking element cooperable with a locking element associated with the other of said platen and housing to secure said other ends of said posts thereto;

d. an oscillatable platen connected to an end of each of said resilient posts; and

e. said posts being positioned between said housing and platen in pairs with a first post of each pair secured to said platen and housing on one side of the longitudinal division in said housing and the second posts of each pair secured to said platen and housing on the other side of the longitudinal division in said housing such that the contiguous end faces of the flanges of each of said first and second posts are in abutting relationship.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be fully comprehended it will now be described, by way of example, with reference to the accompanying drawings in which:

FIG. 1 is a perspective view of a surface-treating machine embodying the invention;

FIG. 2 is a side elevational view in larger scale, with the housing partly broken away and partly in section, of the machine shown in FIG. 1;

FIG. 3 is a sectional view of the machine shown in FIG. 2 taken along line 33 thereof;

FIG. 4 is a bottom plan view, in smaller scale, of the resilient post structure shown in FIG. 3 taken along 44 thereof; and

FIG. 5 is an exploded view, partly in section, of an end of the housing with one resilient post in position and the other post of the pair removed from the housing.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 1 and 2, there is shown an electri- Cally-driven portable surface-treating machine 8 which, as depicted, is a sander. The machine is provided with a clam shell housing 10 comprising a pair of complementary halves 11, 12 which are detachably connected by fastening means such as carriage bolts 13 which are desirably spaced at intervals which will assure close mating of the shells l1, 12. The machine is provided with slots 14 for the entry of cooling air for the motor and with at least one slot 15 for the exit of the air from the machine. A handle 16 is desirably formed integral with the housing 10. An electric switch l7,is mounted in the handle 16 whereby the operator can energize the motor M through switch connection with a source of electric power (not shown). A forwardly positioned hand support 18 is also provided, preferably formed integral with the housing, so that the machine may be grasped by the operator with both hands for easy manual control. An oscillatable platen sub-assembly 19 is connected to the housing at the bottom thereof. It will be understood, of course, that the platen assembly can be so controlled as to provide for reciprocatory and/or orbital movement as desired.

FIG. 2 shows that the motor M is mounted within the housing and the' armature shaft 20 thereof is furnished with a fan 21 to induce cooling air through slots 14. A pinion 22 is formed at the lower end of the shaft 20. A

3 reduction gear mechanism 23 is seated within the housing and i s provided with a gear 24 engageable with the pinion22. The gear 24 is mounted on a shaft 24a which rotates with gear 24 and has an eccentric crank 25 formed at its lower end to connect into the eccentri- {lly drive a bearing bracket 26 which is mounted on Wile back plate 27 of the platen sub-assembly to thus impart the oscillatory motion to the platen 19.

As is depicted more clearly in FIGS. 3 and 5, the platen subassembly 19 comprises a resilient pad 28 which is bonded to the rigid back plate member 27. Both the pad and back plate are preferably essentially planar except for the terminal longitudinally extending edges of the back plate which are turned up along at least a substantial portion of their lengths. The platen sub-assembly 19 in its preferred form is rectangular in plan view as can be seen most clearly from FIG. 1. The pad and back plate are provided adjacent each of their four corners with through

apertures

30, 31 for a purpose to be hereinafter set forth. A plurality of resilient posts 32, desirably formed of hard rubber or other suitable elastomeric material, extend from the housing and rest upon the upper surface of the back plate 27 of the platen sub-assembly 19. Each of the posts 32 is provided with a central bore which desirably accommodates a molded in place insert 33 which is adapted to threadedly receive fastening means such as screw 34 in order to operatively connect the platen assembly to the posts 32. As shown in FIG. 3, screws 34 are inserted through

apertures

30, 31 of the pad 28 and back plate 27, respectively, and screwed into inserts 33 to releaseably lock the platen sub-assembly 19 to the bottoms of the posts 32 at each corner of the housing.

The housing 10 is, as aforestated, of clam shell type. It is provided at each end with a transversely extending, generally U-shaped recess 35 dimensioned to receive a top flange 36 which is formed on each of posts 32 as hereinafter described. As shown most clearly in FIGS. 2, 3 and 5, a pair of posts are positioned at each end of the housing 10, each such pair comprising first and second posts which are spaced from each other and are located on opposite sides of the longitudinally split housing 10. Each such post 32 is provided with a top flange 36 of generally rectangular configuration. The thickness of the flange is such that upon assembly with the housing the flange will be accepted within the recess 35. Preferably a sliding fit between the flange and internal walls of the recess is provided although the height of the recess may be tapered slightly from the opening at the longitudinal split in the housing to the outer sidewall of the housing to enhance retention of the flange within the recess. It will also be appreciated that by forming the recess with a tapered height the insertion of the flange into the recess during assembly will be facilitated, thereby contributing to mass production manufacture of the machine.

The resilient posts 32 are formed with a columnar body portion 32a, preferably of cylindrical configuration, and with a flange section 36 at one extremity of the body portion 32a. One end of the flange preferably begins at the face of the underlying wall of body 32a and the flange extends substantially beyond the face of the opposed sidewall of body 32a. The overall length of the flange is such that when both halves of the housing are brought together into mated relationship, the end faces of the flanges of each respective pair of posts adjacent the longitudinal centerline of the housing are brought into abutting relationship. Such cooperative dimensioning of the lengths of the abutting flanges aids in self-locking of the upper segments of the posts 32 within the recesses. This self locking feature may also be achieved by dimensioning the length of each flange such that it is slightly longer than the transverse extent of the recess in which it is received. Thus, as shown by areas a and b in FIG. 4, a portion of each flange is caused to undergo a relatively small degree of stress upon mating of the housing halves. Such constructions for the abutting flanges serves to maintain the upper segments of the posts in their designed positions within the housing and thereby provide the desired degree of stability for the mounting of the platen. Of course, it will be appreciated that one of the flanges may be formed slightly smaller in length than the length of the recess whereas its abutting flange may be formed with a length sufficiently great so that the desired abutment between contiguous flanges nevertheless occurs.

As may be clearly seen from FIGS. 2 and 3 of the drawings the posts 32 are desirably positioned one in each corner of the housing. The flanges 36 of the post pairs at each end of the housing on opposite sides of the longitudinal split in the housing extend a substantial distance beyond the body of the post towards the inner portion of the housing. The length of the flanges are preferably approximately twice the dimension of the post body 320 although such proportion is by no means critical. Thus, during operation of the machine the upper and lower segments of the posts 32 are maintained in relatively stable and fixed relationship relative to the housing 10 and platen 19 to which they are secured. Yet the intermediate region of the body 32a is afforded the degree of resiliency necessary to impart the desired oscillatory motion to the platen.

From the foregoing it will be seen that applicant has provided an extremely simple construction for securing the oscillatable platen to the housing by means of the plurality of resilient posts. Nevertheless, the resilient posts are maintained within the housing at the predetermined designed locations by virtue of the particular flange construction retained within the transverse recess in the housing and through use of the fastening means at the other end of the posts.

Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.

Having thus set forth the nature of the invention, what is claimed herein is:

1. In an electrically-driven portable surface-treating machine in which the motor and means driven thereby for oscillating a platen are mounted within a longitudinally divided clam shell housing and said platen is connected to said housing by being secured to a plurality of resilient posts connected to said housing, the improvement which comprises:

a. transversely extending recesses formed in the opposite ends of the housing,

b. a plurality of resilient posts each of which is provided at one end thereof with a flange dimensioned to fit within said recesses to secure said one end of the post therewithin,

c. said posts being provided at the other end thereof with a locking element cooperable with a locking element associated with the other of said platen and housing to secure said other ends of said posts thereto,

cl. an oscillatable platen connected to an end of each of said resilient posts,

e. said posts being positioned between said housing and platen in pairs with a first post of each pair secured to said platen and housing on one side of the longitudinal division in said housing and the second post of each pair secured to said platen and housing on the other side of the longitudinal division in said housing, and

f. each of said posts is located in a comer of said housing with the flange of each post in each said pair of posts extending towards the flange of the other posts in the pair a predetermined distance beyond the columnar body of the post such that the contiguous end faces of the flanges of each of said first and second posts are in abutting relationship, and the lengths of the abutting flanges are sufficiently great to stress the terminal portion of each such flange in the region of the abutting end faces upon assembly of the divided halves of the housing.

2. A portable sanding tool comprising:

a. a clam shell housing having a pair of housing halves interconnected to each other along a longitudinal split in said housing,

b. an electric motor mounted in the housing,

c. drive means mounted in the housing to be powered by the motor,

d. a pair of spaced recesses formed in each housing halve to extend transversely of the longitudinal split,

e. each pair of recesses in one housing halve formed in alignment with the pair of recesses in the other housing halve,

f. a plurality of resilient posts adapted to extend from a position adjacent each comer of the housing,

g. a platen connected to each of the resilient posts, and operatively connected to be driven by the drive means,

h. each of the resilient posts having an integrally formed flange extending a predetermined distance outwardly therefrom to define an end face thereon, and

. each flange insertable into one of the recesses of the housing halves to be independently held therein and having the end face of the flange extending toward the longitudinal split whereby on assembly of the housing halves the adjacent end faces to come into engagement with each other forcing the resilient posts to be locked into their respective comer positions.

Claims

1. In an electrically-driven portable surface-treating machine in which the motor and means driven thereby for oscillating a platen are mounted within a longitudinally divided clam shell housing and said platen is connected to said housing by being secured to a plurality of resilient posts connected to said housing, the improvement which comprises: a. transversely extending recesses formed in the opposite ends of the housing, b. a plurality of resilient posts each of which is provided at one end thereof with a flange dimensioned to fit within said recesses to secure said one end of the post therewithin, c. said posts being provided at the other end thereof with a locking element cooperable with a locking element associated with the other of said platen and housing to secure said other ends of said posts thereto, d. an oscillatable platen connected to an end of each of said resilient posts, e. said posts being positioned between said housing and platen in pairs with a first post of each pair secured to said platen and housing on one side of the longitudinal division in said housing and the second post of each pair secured to said platen and housing on the other side of the longitudinal division in said housing, and f. each of said posts is located in a corner of said housing with the flange of each post in each said pair of posts extending towards the flange of the other posts in the pair a predetermined distance beyond the columnar body of the post such that the contiguous end faces of the flanges of each of said first and second posts are in abutting relationship, and the lengths of the abutting flanges are sufficiently great to stress the terminal portion of each such flange in the region of the abutting end faces upon assembly of the divided halves of the housing.

2. A portable sanding tool comprising: a. a clam shell housing having a pair of housing halves interconnected to each other along a longitudinal split in said housing, b. an electric motor mounted in the housing, c. drive means mounted in the housing To be powered by the motor, d. a pair of spaced recesses formed in each housing halve to extend transversely of the longitudinal split, e. each pair of recesses in one housing halve formed in alignment with the pair of recesses in the other housing halve, f. a plurality of resilient posts adapted to extend from a position adjacent each corner of the housing, g. a platen connected to each of the resilient posts, and operatively connected to be driven by the drive means, h. each of the resilient posts having an integrally formed flange extending a predetermined distance outwardly therefrom to define an end face thereon, and i. each flange insertable into one of the recesses of the housing halves to be independently held therein and having the end face of the flange extending toward the longitudinal split whereby on assembly of the housing halves the adjacent end faces to come into engagement with each other forcing the resilient posts to be locked into their respective corner positions.