US2787251A

US2787251A - Muffled vibrator

Info

Publication number: US2787251A
Application number: US486820A
Authority: US
Inventors: James E Becker
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-02-08
Filing date: 1955-02-08
Publication date: 1957-04-02
Anticipated expiration: 1974-04-02

Description

April 2, 1957 J. E. BECKER 2,787,251

MUFFLED VIBRATOR Filed Feb. s, 1955 IN1 'ENToR. dal/les E. Becker BY g. 4 @fd/277% @MM 27M /4 TfOR/VL'YS railroad hopper cars, bins, and chutes.

United States Patent() MUFFLED. VIBRATOR JamesE. Becker, Rocky River,V Ohio Application February..8,1955,-SerialNo. 486320 2 Claims. (Cl. 121-17)` The invention relates to industrial vibrators such `as are used, for example, to facilitate discharge of granulated or nondescript comminuted material from sloping walled containers, such as discharge of sand or slag from Other familiar uses are, for example, vibration tables, foundry shakeouts, pneumatic hammers or the like.

As is familiar to those skilled in related arts of this type, a vibrator usually operates on a principle involving rapid reciprocati'on, or perhaps off-center rotation, of a movable element within a housing, said housing being bolted or otherwise irmly attached to the article which must be Vibrateds such as the cope of a mold or the body of the bin or hopper car. Compressed air is the usual motive power for the vibrator, and the exhaust air normally escapes to atmosphere, the resulting air disturbance causing loud, and harsh noises, the pitch of course depending on the frequency of successive exhaust discharges. In an enclosed space such as a factory or workshop, or when attached lto a steel walled hopper or other container, the resultant noise can be most irritating to anyone in the vicinity. The ordinary pedestrian has been subjected to the disturbing eiect created by the use of pneumatic hammers by pavement workers.

An object of the present invention is to provide a pneumatic power tool of the vibrator type wherein the exhaust discharge noise is reduced almost to an imperceptible level, certainly to a non-irritating level, without reducing the efficiency of the vibrator.

Another object of the invention is to provide a vibrator of the type defined in the last preceding paragraph which can be manufactured at a cost not substantially exceeding the cost of a conventional non-muled vibrator.

Other objects and advantages will be apparent from a study of the following description of several embodiments of the invention, in conjunction with the accompanying drawings, in which:

Fig. 1 is a sectional View .taken axially on a vibrator embodying my invention.

Fig. 2 is a view partly in plan and partly in section, showing a slightly modified form of my invention.

Fig. 3 is a View similar to Fig 2 but showing yet another embodiment of the invention.

Fig. 4 is an enlarged view showing a structural detail of part of the apparatus shown in Fig. 3.

Referring rst to Fig. 1, there is shown a housing of tubular character and of sturdy construction having ra bored aperture 11 Itherethrough, the aperture being closed at both ends by

end plates

12 and 13 which are held in tight, leak-proof contact with the body by tie bolts 14. The tie bolts can pass outside the body, as indicated in the embodiments of Figs. 2 and 3, passing between lugs in the end plates which clear the body portion 1i). Obviously the end plates could be held in place by studs threaded into rtapped apertures in the body, although the method I show avoids the necessity of drilling and tapping the body ends.

A reciprocable member, or piston 15 has a slidable it within boreV 11 and ithastwo annular peripheral grooves 1'6 and 17, groove 16` having iiuid ll'owA communication with Ithe piston end 15a through passage 16a, and; groove 17 being` in communication with the piston' end 15b through passage 17a thereby providing access to

endhead chambers

18 and 19.

A bored exhaust passage, 20 extends' longitudinally througlithe body wall, and it has two portsl 2T and 22 communicating with respective opposedj end chambers 18 and' 1'9'. EndE plate 13 hasexhaust ports 23 establishingv communication` between. exhaust `passage 20" andt at'- nrosphere. Spaced from exhaust passage 20`tlie' bodywall has an air inlet port 24 located centrally to permit periodic registry with either groove 16 or groove 17 on the piston 15. To facilitate proper operation, as described immediately hereinafter, the inner body wall has an annular groove 25 in registry with port 24. Exhaust passage 20 is packed with permeable material such as bronze wool 27, or any sound deadening material.

In operation the device functions as follows. In the position shown in Fig. 1, grooves 16 and 25 are in registry. If compressed air is admitted through port 24, it will pass through passage 16a to end chamber 1S, whereupon piston 15 is thrown towards the left end. This movement quickly interrupts communication between port 24 and passage 16a but the piston continues its movement (chamber 19 being still vented through outlets 22, 2i), and 23 in succession) until piston end 15a clears outlet 21 at which time chamber 18 is vented to exhaust through 21, 20, and 23, tand passage 22 is closed by piston end 15b. At this stage compression of residual air in chamber begins to impede the movement of piston 15, and about the same time groove 17 comes to registry with groove 25 and port 24 thereby admitting compressed air through passage 17a to chamber 19, reversing the piston motion and completing a cycle. All this of course takes place with great rapidity. In this design the piston never comes to actual contact with either

plate

12 or 13.

It will be observed that the exhaust air, from

chambers

18 and 19 alternately, passes through respective passages 21 and 22, and then through the permeable material 27 before passing outwardly through vents 23 to atmosphere. l have found that the provision of the muling passage 20 very materially quiets the operation of the vibrator so that it becomes actually unnoticeable except for 'a slight hissing noise7 and there is no sensation of motor boating, or no siren-like noise, these latter two phenomena being exempliiications lof low or high fre quency exhaust discharges. The invention of course is not limited to vibrators of the type just mentioned, but can also be utilized in connection with rotary type vibrators in which the exhaust is practically continuous.

In the embodiment of ig. l, it will be noted that the ultimate discharge is Iall through the right end so that the alternate discharges from

chambers

18 and 19 pass through respectively varying amounts of mufing material. In the embodiment illustrated in Fig. 2, the ports 28 have been drilled centrally of the length of the exhaust passage 20a, so that air escaping from either of the end chambers of the cylinder tnavels through approximately the same amount of mui'lling material.

Figs. 3 and 4 show another embodiment wherein the exhaust chamber 20b has a conventional type of muffler inserted therein. Any typeof noise-muflling device will be satisfactory las long as it is adaptable 'to the somewhat limited space requirements of the exhaust passage 2012.

Merely as an illustration, I show several concentric tubes` 29 and 30, spaced from each other and from the exhaust passage wall. The tubes have a plurality of perforations 31 therethrough, and there are annular spacers 32 which 3 serve to baffle air flow and maintain the spacing of the tubes. This type of muffler can be manufactured separately and inserted endwise into chamber 20b. Air emerging from port 33, for example, must travel through a circuitous course before exhausting to atmosphere through vents 34, while undergoing successive expansions.

What I claim is:

1. Vibrator means of the character described compris ing an elongated body having an axial aperture therein, an inlet port to each end `of said aperture from the body exterior, a second aperture in the body wall generally paral- Ilel to said lirst aperture, and having an opening to atmosphere, a pair of exhaust ports, one from each of the opposite ends of said iirst aperture and opening into sai'd second aperture, said second aperture being filled with noise muting material, and an element in said irst aperture rapidly reciprooable responsive to admission of pressure uid to said inlet port.

2. Vibrator means as defined in claim l wherein the opening to atmosphere from said second aperture is substantially evenly spaced from, and between, said exhaust ports whereby the exhaust from each end of the said first aperture travels approximately an equal distance through said noise muling material.

References Cited in the file of this patent UNITED STATES PATENTS 2,073,480 Jimerson Mar. 9, 1937 2,516,949 Bourne Aug. 1, 1950 2,590,155 Cannon Mar. 25, 1952 2,678,637 Doeden May 18, 1954