VIBRATION ABSORBER FOR A SUPPORTED MEMBER

• US 3,690,414 A
• Filed: 11/04/1970
• Issued: 09/12/1972
• Est. Priority Date: 11/04/1970
• Status: Expired due to Term

• Current Assignee: John R. Hasz, Trilok C. Aggarwal
• Original Assignee: John R. Hasz, Trilok C. Aggarwal
• Inventors: Hasz, John R., Aggarwal, Trilok C.
• Primary Examiner(s): Reger, Duane A.
• Application Number:
  US05/086,727
• Time in Patent Office: 678 Days
• Field of Search: 188/1B 408/143
• US Class Current: 188/378
• CPC Class Codes: B23Q 11/0032 Arrangements for preventing or isolating vibrations in parts of the machine B23B29/022, B23D47/005 take precedence; means for damping or suppressing vibrations, in general F16F
• CPC Class Codes: F16F 7/108 on plastics springs
• CPC Class Codes: Y10T 408/76 Tool-carrier with vibration-damping means

Abstract

A series of damper dampens the vibrations in a bar extending from a quill of a bar milling machine with the damper damping each of a plurality of different natural frequencies of the extending bar depending upon the length of the extension of the bar from the quill. The damper includes a plurality of damper masses mounted on a rod with viscoelastic material between each of the adjacent damper masses and also between the supports for the rod and the adjacent damper masses. By selecting the weights of the masses and their locations on the rod, the length and diameter of the rod, and the stiffness of the viscoelastic material, the damper is designed to cover a wide frequency range, i.e., bar extension. The damper need not be tuned for each bar extension each time that the bar has a different extension since the plurality of damper masses permits the damper to dampen vibrations anywhere within the designed frequency range.

Claims

1. A vibration absorber for a supported member subject to vibrations of different frequencies and said absorber absorbing vibrations of the supported member within a range of frequencies, said absorber including:

damping means supported by the supported member; and

said damping means including;

a plurality of separate damper masses disposed within the supported member and forming at least one series damper;

a rod supported within the supported member and supporting said damper masses; and

viscoelastic means cooperating with each of said damper masses, said viscoelastic means and said rod cooperating to absorb vibrations of the supported member within a range of frequencies of vibration.

2. THe vibration absorber according to claim 1 in which each of said damper masses of said damping means has a weight equal to at least 10 percent of the maximum effective weight of the supported member.

3. The vibration absorber according to claim 1 including:

means to support each end of said rod; and

means to connect each of said end rod support means to the supported member.

4. The vibration absorber according to claim 3 in which said viscoelastic means is disposed between each of said end rod support means and the adjacent of said damper masses and between each adjacent pair of said damper masses of the same series damper.

5. The vibration absorber according to claim 4 including:

at least one rod support means disposed intermediate the ends of said rod;

said damper masses being supported on said rod to form at least two series dampers with each of the series dampers being separated from the adjacent series damper by said intermediate rod support means; and

said viscoelastic means is disposed between said intermediate rod support means and said damper mass on each side thereof.

6. The vibration absorber according to claim 5 including:

means to connect said rod to each of said end rod support means; and

means to adjust the preload on said viscoelastic means by adjusting the connection of said rod to one of said end rod support means.

7. The vibration absorber according to claim 5 in which said rod has a first diameter between one of said end rod support means and said intermediate rod support means and a second diameter, different than the first diameter, between the other of said end rod support means and said intermediate rod support means.

8. The vibration absorber according to claim 1 in which each of said damper masses has a cylindrical shape.

9. The vibration absorber according to claim 1 in which each of said viscoelastic means comprises a single element of viscoelastic material concentrically disposed with respect to said rod.

10. The vibration absorber according to claim 1 including means to adjust the preload on said viscoelastic means.